2000 Microchip Technology Inc. May 2000 DS30277C
In-Circuit Serial Programming™
(ICSP™) Guide
DS30277C - page ii 2000 Microchip Technology Inc.
All rights reserved. Copyright 2000, Microchip Technology
Incorporated, USA. Information contained in this publication regarding
device applications and the like is intended through suggestion only and
may be superseded by updates. No representation or warranty is given
and no liability is assumed by Microchip Technology Incorporated with
respect to the accuracy or use of such information, or infringement of
patents arising from such use or otherwise. Use of Microchip’s products
as critical components in life support systems is not authorized except
with express written approval by Microchip. No licenses are conveyed,
implicitly or otherwise, under any intellectual property rights.”
The Microchip name and logo, PIC, PICmicro, PRO MATE, PICSTART,
MPLAB, and The Embedded Control Solutions Company are registered
trademarks of Microchip Technology Inc. in the U.S.A. and other coun-
tries.
In-Circuit Serial Programming and ICSP are trademarks and SQTP is a
service mark of Microchip Technology Inc.
All other trademarks mentioned herein are property of their respective
companies.
2000 Microchip Technology Inc. DS30277C-page iii
PAGE
SECTION 1 INTRODUCTION
In-Circuit Serial Programming™ (ICSP™) Guide ............................................................................................. 1-1
SECTION 2 TECHNICAL BRIEFS
How to Implement ICSP™ Using PIC12C5XX OTP MCUs ............................................................................. 2-1
How to Implement ICSP™ Using PIC16CXXX OTP MCUs ............................................................................. 2-9
How to Implement ICSP™ Using PIC17CXXX OTP MCUs ........................................................................... 2-15
How to Implement ICSP™ Using PIC16F8X FLASH MCUs .......................................................................... 2-21
SECTION 3 PROGRAMMING SPECIFICATIONS
In-Circuit Serial Programming for PIC12C5XX OTP MCUs ............................................................................. 3-1
In-Circuit Serial Programming for PIC12C67X and PIC12CE67X OTP MCUs .............................................. 3-15
In-Circuit Serial Programming for PIC14000 OTP MCUs ............................................................................... 3-27
In-Circuit Serial Programming for PIC16C55X OTP MCUs ............................................................................ 3-39
In-Circuit Serial Programming for PIC16C6XX/7XX/9XX OTP MCUs ............................................................ 3-51
In-Circuit Serial Programming for PIC17C7XX OTP MCUs ...........................................................................3-71
In-Circuit Serial Programming for PIC18CXXX OTP MCUs ...........................................................................3-97
In-Circuit Serial Programming for PIC16F62X FLASH MCUs ...................................................................... 3-135
In-Circuit Serial Programming for PIC16F8X FLASH MCUs ........................................................................ 3-149
In-Circuit Serial Programming for PIC16F8XX FLASH MCUs ..................................................................... 3-165
SECTION 4 APPLICATION NOTES
In-Circuit Serial Programming™ (ICSP™) of Calibration Parameters Using a PICmicro® Microcontroller ...... 4-1
Table of Contents
DS30277C-page iv © 2000 Microchip Technology Inc.
DS30277C-page 1-ii 2000 Microchip Technology Inc.
2000 Microchip Technology Inc. DS30277C-page 1-1
INTRODUCTION
WHAT IS IN-CIRCUIT SERIAL
PROGRAMMING (ICSP)?
In-System Programming (ISP) is a technique where a
programmable device is programmed after the device
is placed in a circuit board.
In-Circuit Serial Programming (ICSP) is an enhanced
ISP technique implemented in Microchip’s PICmicro®
One-Time-Programmable (OTP) and FLASH RISC
microcontrollers (MCU). Use of only two I/O pins to
serially input and output data makes ICSP easy to use
and less intrusive on the normal operation of the MCU.
Because they can accommodate rapid code changes
in a manufacturing line, PICmicro OTP and FLASH
MCUs offer tremendous flexibility, reduce development
time and manufacturing cycles, and improve time to
market.
In-Circuit Serial Programming enhances the flexibility
of the PICmicro even further.
This In-Circuit Serial Programming Guide is designed
to show you how you can use ICSP to get an edge over
your competition. Microchip has helped its customers
implement ICSP using PICmicro MCUs since 1992.
Contact your local Microchip sales representative today
for more information on implementing ICSP in your
product.
PICmicro MCUs MAKE IN-CIRCUIT
SERIAL PROGRAMMING A CINCH
Unlike many other MCUs, most PICmicro MCUs offer a
simple serial programming interface using only two I/O
pins (plus power, ground and VPP). Following very sim-
ple guidelines, these pins can be fully utilized as I/O
pins during normal operation and programming pins
during ICSP.
ICSP can be activated through a simple 5-pin connec-
tor and a standard PICmicro programmer supporting
serial programming mode such as Microchip’s
PRO MATE® II.
No other MCU has a simpler and less intrusive Serial
Programming Mode to facilitate your ICSP needs.
WHAT CAN I DO WITH IN-CIRCUIT
SERIAL PROGRAMMING?
ICSP is truly an enabling technology that can be used
in a variety of ways including:
•Reduce Cost of Field Upgrades
The cost of upgrading a system’s code can be
dramatically reduced using ICSP. With very little
effort and planning, a PICmicro OTP- or FLASH-
based system can be designed to have code updates
in the field.
For PICmicro FLASH devices, the entire code
memory can be rewritten with new code. In PICmicro
OTP devices, new code segments and parameter
tables can be easily added in program memory areas
left blank for update purpose. Often, only a portion of
the code (such as a key algorithm) requires update.
•Reduce Time to Market
In instances where one product is programmed with
different customer codes, generic systems can be
built and inventoried ahead of time. Based on actual
mix of customer orders, the PICmicro MCU can be
programmed using ICSP, then tested and shipped.
The lead-time reduction and simplification of finished
goods inventory are key benefits.
•Calibrate Your System During Manufacturing
Many systems require calibration in the final stages
of manufacturing and testing. Typically, calibration
parameters are stored in Serial EEPROM devices.
Using PICmicro MCUs, it is possible to save the addi-
tional system cost by programming the calibration
parameters directly into the program memory.
•Add Unique ID Code to Your System During
Manufacturing
Many products require a unique ID number or a
serial number. An example application would be a
remote keyless entry device. Each transmitter has a
unique “binary key” that makes it very easy to pro-
gram in the access code at the very end of the man-
ufacturing process and prior to final test.
Serial number, revision code, date code, manufac-
turer ID and a variety of other useful information can
also be added to any product for traceability. Using
ICSP, you can eliminate the need for DIP switches or
jumpers.
In-Circuit Serial Programming™ (ICSP™) Guide
In-Circuit Serial Programming and ICSP are trademarks of Microchip Technology Inc. SQTP is a service mark of Microchip Technology Inc.
Introduction
DS30277C-page 1-2 2000 Microchip Technology Inc.
In fact, this capability is so important to many of our
customers that Microchip offers a factory program-
ming service called Serialized Quick Turn Program-
ming (SQTPSM), where each PICmicro MCU device is
coded with up to 16 bytes of unique code.
•Calibrate Your System in the Field
Calibration need not be done only in the factory.
During installation of a system, ICSP can be used to
further calibrate the system to actual operating
environment.
In fact, recalibration can be easily done during
periodic servicing and maintenance. In OTP parts,
newer calibration data can be written to blank
memory locations reserved for such use.
•Customize and Configure Your System in the
Field
Like calibration, customization need not done in the
factory only. In many situations, customizing a
product at installation time is very useful. A good
example is home or car security systems where ID
code, access code and other such information can
be burned in after the actual configuration is deter-
mined. Additionally, you can save the cost of DIP
switches and jumpers, which are traditionally used.
•Program Dice When Using Chip-On-Board
(COB)
If you are using COB, Microchip offers a comprehen-
sive die program. You can get dice that are
preprogrammed, or you may want to program the die
once the circuit board is assembled. Programming
and testing in one single step in the manufacturing
process is simpler and more cost effective.
PROGRAMMING TIME
CONSIDERATIONS
Programming time can be significantly different
between OTP and FLASH MCUs. OTP (EPROM) bytes
typically program with pulses in the order of several
hundred microseconds. FLASH, on the other hand,
require several milliseconds or more per byte (or word)
to program.
Figure 1 and Figure 2 below illustrate the programming
time differences between OTP and FLASH MCUs.
Figure 1 shows programming time in an ideal program-
mer or tester, where the only time spent is actually pro-
gramming the device. This is only important to illustrate
the minimum time required to program such devices,
where the programmer or the tester is fully optimized.
Figure 2 is a more realistic programming time compar-
ison, where the “overhead” time for programmer or a
tester is built in. The programmer often requires 3 to 5
times the “theoretically” minimum programming time.
FIGURE 1: PROGRAMMING TIME FOR FLASH AND OTP MCUS
(THEORETICAL MINIMUM TIMES)
0
5
10
15
20
25
30
35
40
45
0 1K 2K 4K 8K 16K
Typical
Flash
MCU
Microchip
OTP MCU
Programming Time (Seconds)
Note 1: The programming times shown here only include the total programming time for all memory. Typically, a
programmer will have quite a bit of overhead over this “theoretical minimum” programming time.
2: In the PIC16CXX MCU (used here for comparison) each word is 14 bits wide. For the sake of simplicity,
each word is viewed as “two bytes”.
Memory Size (in bytes)
Ty p i ca l
FLASH MCU
Microchip
OTP MCU
2000 Microchip Technology Inc. DS30277C-page 1-3
Introduction
FIGURE 2: PROGRAMMING TIME FOR FLASH AND OTP MCUS
(TYPICAL PROGRAMMING TIMES ON A PROGRAMMER)
Ramifications
The programming time differences between FLASH
and OTP MCUs are not particular material for prototyp-
ing quantities. However, its impact can be significant in
large volume production.
MICROCHIP PROVIDES A COMPLETE
SOLUTION FOR ICSP
Products
Microchip offers the broadest line of ICSP-capable
MCUs:
•PIC12C5XX OTP, 8-pin Family
•PIC12C67X OTP, 8-pin Family
•PIC12CE67X OTP, 8-pin Family
•PIC16C6XX OTP, Mid-Range Family
•PIC17C7XX OTP High-End Family
•PIC18CXXX OTP, High-End Family
•PIC16F62X FLASH, Mid-Range Family
•PIC16F8X FLASH, Mid-Range Family
•PIC6F8XX FLASH, Mid-Range Family
All together, Microchip currently offers over 40 MCUs
capable of ICSP.
Development Tools
Microchip offers a comprehensive set of development
tools for ICSP that allow system engineers to quickly
prototype, make code changes and get designs out the
door faster than ever before.
PRO MATE II Production Programmer – a production
quality programmer designed to support the Serial
Programming Mode in MCUs up to midvolume produc-
tion. PRO MATE II runs under DOS in a Command Line
Mode, Microsoft® Windows® 3.1, Windows® 95/98,
and Windows NT®. PRO MATE II is also capable of
Serialized Quick Turn ProgrammingSM (SQTPSM),
where each device can be programmed with up to 16
bytes of unique code.
Microchip offers an ICSP kit that can be used with the
Universal Microchip Device Programmer,
PRO MATE II. Together these two tools allow you to
implement ICSP with minimal effort and use the ICSP
capability of Microchip’s PICmicro MCUs.
Technical support
Microchip has been delivering ICSP capable MCUs
since 1992. Many of our customers are using ICSP
capability in full production. Our field and factory appli-
cation engineers can help you implement ICSP in your
product.
Programming Time (Seconds)
Memory Size (in bytes)
Note 1: The programming times shown are actual programming times on vendor supplied programmers.
2: Microchip OTP programming times are based on PRO MATE II programmer.
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
0 1K2K4K8K16K
Typical
Flash
MCU
Microchip
OTP MCU
Typica l
FLASH MCU
Microchip
OTP MCU
Introduction
DS30277C-page 1-4 2000 Microchip Technology Inc.
NOTES:
2000 Microchip Technology Inc. DS30277C-page 2-i
HOW TO IMPLEMENT ICSP™ USING PIC12C5XX OTP MCUS ........................................................... 2-1
HOW TO IMPLEMENT ICSP™ USING PIC16CXXX OTP MCUS ..........................................................2-9
HOW TO IMPLEMENT ICSP™ USING PIC17CXXX OTP MCUS ........................................................2-15
HOW TO IMPLEMENT ICSP™ USING PIC16F8X FLASH MCUS .......................................................2-21
SECTION 2
TECHNICAL BRIEFS
DS30277C-page 2-ii 2000 Microchip Technology Inc.
2000 Microchip Technology Inc. Preliminary DS91017B-page 2-1
TB017
INTRODUCTION
The technical brief describes how to implement in-cir-
cuit serial programming™ (ICSP) using the
PIC12C5XX OTP PICmicro® MCU.
ICSP is a simple way to manufacture your board with
an unprogrammed PICmicro MCU and program the
device just before shipping the product. Programming
the PIC12C5XX MCU in-circuit has many advantages
for developing and manufacturing your product.
•Reduces inventory of products with old
firmware. With ICSP, the user can manufacture
product without programming the PICmicro MCU.
The PICmicro MCU will be programmed just
before the product is shipped.
•ICSP in production. New software revisions or
additional software modules can be programmed
during production into the PIC12C5XX MCU.
•ICSP in the field. Even after your product has
been sold, a service man can update your
program with new program modules.
•One hardware with different software. ICSP
allows the user to have one hardware, whereas
the PIC12C5XX MCU can be programmed with
different types of software.
•Last minute programming. Last minute pro-
gramming can also facilitate quick turnarounds on
custom orders for your products.
IN-CIRCUIT SERIAL PROGRAMMING
To implement ICSP into an application, the user needs
to consider three main components of an ICSP system:
Application Circuit, Programmer and Programming
Environment.
Application Circuit
During the initial design phase of the application circuit,
certain considerations have to be taken into account.
Figure 1 shows and typical circuit that addresses the
details to be considered during design. In order to
implement ICSP on your application board you have to
put the following issues into consideration:
1. Isolation of the GP3/MCLR/VPP pin from the rest
of the circuit.
2. Isolation of pins GP1 and GP0 from the rest of
the circuit.
3. Capacitance on each of the VDD, GP3/MCLR/
VPP, GP1, and GP0 pins.
4. Interface to the programmer.
5. Minimum and maximum operating voltage for
VDD.
FIGURE 1: TYPICAL APPLICATION CIRCUIT
Author: Thomas Schmidt
Microchip Technology Inc.
Application PCB
PIC12C5XX
GP3/MCLR/VPP
VDD
VSS
GP0
GP1
VDD VDD
To application circuit
Isolation circuits
ICSP Connector
How to Implement ICSP™ Using PIC12C5XX OTP MCUs
PICmicro, PRO MATE and PICSTART are registered trademarks of Microchip Technology Inc.
In-Circuit Serial Programming and ICSP are trademarks of Microchip Technology Inc.
TB017
DS91017B-page 2-2 Preliminary 2000 Microchip Technology Inc.
Isolation of the GP3/MCLR/VPP Pin from the
Rest of the Circuit
PIC12C5XX devices have two ways of configuring the
MCLR pin:
•MCLR can be connected either to an external RC
circuit or
•MCLR is tied internally to VDD
When GP3/MCLR/VPP pin is connected to an external
RC circuit, the pull-up resistor is tied to VDD, and a
capacitor is tied to ground. This circuit can affect the
operation of ICSP depending on the size of the capac-
itor.
Another point of consideration with the GP3/MCLR/VPP
pin, is that when the PICmicro MCU is programmed,
this pin is driven up to 13V and also to ground. There-
fore, the application circuit must be isolated from the
voltage coming from the programmer.
When MCLR is tied internally to VDD, the user has only
to consider that up to 13V are present during program-
ming of the GP3/MCLR/VPP pin. This might affect other
components connected to that pin.
For more information about configuring the GP3/
MCLR/VPP internally to VDD, please refer to the
PIC12C5XX data sheet (DS40139).
Isolation of Pins GP1 and GP0 from the Rest
of the Circuit
Pins GP1 and GP0 are used by the PICmicro MCU for
serial programming. GP1 is the clock line and GP0 is
the data line.
GP1 is driven by the programmer. GP0 is a bidirectional
pin that is driven by the programmer when program-
ming and driven by the PICmicro MCU when verifying.
These pins must be isolated from the rest of the appli-
cation circuit so as not to affect the signals during pro-
gramming. You must take into consideration the output
impedance of the programmer when isolating GP1 and
GP0 from the rest of the circuit. This isolation circuit
must account for GP1 being an input on the PICmicro
MCU and for GP0 being bidirectional pin.
For example, PRO MATE® II has an output impedance
of 1 kΩ. If the design permits, these pins should not be
used by the application. This is not the case with most
designs. As a designer, you must consider what type of
circuitry is connected to GP1 and GP0 and then make
a decision on how to isolate these pins.
Total Capacitance on VDD, GP3/MCLR/VPP,
GP1, and GP0
The total capacitance on the programming pins affects
the rise rates of these signals as they are driven out of
the programmer. Typical circuits use several hundred
microfarads of capacitance on VDD, which helps to
dampen noise and improve electromagnetic interfer-
ence. However, this capacitance requires a fairly strong
driver in the programmer to meet the rise rate timings
for VDD.
Interface to the Programmer
Most programmers are designed to simply program the
PICmicro MCU itself and don’t have strong enough
drivers to power the application circuit.
One solution is to use a driver board between the pro-
grammer and the application circuit. The driver board
needs a separate power supply that is capable of driv-
ing the VPP, VDD, GP1, and GP0 pins with the correct
ramp rates and also should provide enough current to
power-up the application circuit.
The cable length between the programmer and the cir-
cuit is also an important factor for ICSP. If the cable
between the programmer and the circuit is too long, sig-
nal reflections may occur. These reflections can
momentarily cause up to twice the voltage at the end of
the cable, that was sent from the programmer. This volt-
age can cause a latch-up. In this case, a termination
resistor has to be used at the end of the signal line.
Minimum and Maximum Operating Voltage
for VDD
The PIC12C5XX programming specification states that
the device should be programmed at 5V. Special con-
siderations must be made if your application circuit
operates at 3V only. These considerations may include
totally isolating the PICmicro MCU during program-
ming. The other point of consideration is that the device
must be verified at minimum and maximum operation
voltage of the circuit in order to ensure proper program-
ming margin.
For example, a battery driven system may operate from
three 1.5V cells giving an operating voltage range of
2.7V to 4.5V. The programmer must program the device
at 5V and must verify the program memory contents at
both 2.7V and 4.5V to ensure that proper programming
margins have been achieved.
2000 Microchip Technology Inc. Preliminary DS91017B-page 2-3
TB017
THE PROGRAMMER
PIC12C5XX MCUs only use serial programming and,
therefore, all programmers supporting these devices
will support the ICSP. One issue with the programmer
is the drive capability. As discussed before, it must be
able to provide the specified rise rates on the ICSP sig-
nals and also provide enough current to power the
application circuit. It is recommended that you buffer
the programming signals.
Another point of consideration for the programmer is
what VDD levels are used to verify the memory contents
of the PICmicro MCU. For instance, the PRO MATE II
verifies program memory at the minimum and maxi-
mum VDD levels for the specified device and is there-
fore considered a production quality programmer. On
the other hand, the PICSTART® Plus only verifies at 5V
and is for prototyping use only. The PIC12C5XX pro-
gramming specifications state that the program mem-
ory contents should be verified at both the minimum
and maximum VDD levels that the application circuit will
be operating. This implies that the application circuit
must be able to handle the varying VDD voltages.
There are also several third-party programmers that
are available. You should select a programmer based
on the features it has and how it fits into your program-
ming environment. The Microchip Development Sys-
tems Ordering Guide (DS30177) provides detailed
information on all our development tools. The Microchip
Third Party Guide (DS00104) provides information on
all of our third party development tool developers.
Please consult these two references when selecting a
programmer. Many options exist including serial or par-
allel PC host connection, stand-alone operation, and
single or gang programmers.
PROGRAMMING ENVIRONMENT
The programming environment will affect the type of
programmer used, the programmer cable length, and
the application circuit interface. Some programmers
are well suited for a manual assembly line while others
are desirable for an automated assembly line. A gang
programmer should be chosen for programming multi-
ple MCUs at one time. The physical distance between
the programmer and the application circuit affects the
load capacitance on each of the programming signals.
This will directly affect the drive strength needed to pro-
vide the correct signal rise rates and current. Finally,
the application circuit interface to the programmer
depends on the size constraints of the application cir-
cuit itself and the assembly line. A simple header can
be used to interface the application circuit to the pro-
grammer. This might be more desirable for a manual
assembly line where a technician plugs the
programmer cable into the board.
A different method is the uses spring loaded test pins
(often referred as pogo-pins). The application circuit
has pads on the board for each of the programming sig-
nals. Then there is a movable fixture that has pogo pins
in the same configuration as the pads on the board.
The application circuit is moved into position and the
fixture is moved such that the spring loaded test pins
come into contact with the board. This method might be
more suitable for an automated assembly line.
After taking into consideration the issues with the
application circuit, the programmer, and the program-
ming environment, anyone can build a high quality,
reliable manufacturing line based on ICSP.
OTHER BENEFITS
ICSP provides several other benefits such as calibra-
tion and serialization. If program memory permits, it
would be cheaper and more reliable to store calibration
constants in program memory instead of using an
external serial EEPROM.
Field Programming of PICmicro OTP MCUs
An OTP device is not normally capable of being repro-
grammed, but the PICmicro MCU architecture gives
you this flexibility provided the size of your firmware is
less than half that of the desired device.
This method involves using jump tables for the reset
and interrupt vectors. Example 1 shows the location of
a main routine and the reset vector for the first time a
device with 0.5K-words of program memory is pro-
grammed. Example 2 shows the location of a second
main routine and its reset vector for the second time the
same device is programmed. You will notice that the
GOTO Main that was previously at location 0x0002 is
replaced with an NOP. An NOP is a program memory
location with all the bits programmed as 0s. When the
reset vector is executed, it will execute an NOP and
then a GOTO Main1 instruction to the new code.
TB017
DS91017B-page 2-4 Preliminary 2000 Microchip Technology Inc.
EXAMPLE 1: LOCATION OF THE FIRST MAIN ROUTINE AND ITS INTERRUPT VECTOR
MOVLW XX
MOVWF OSCAL
PROGRAM MEMORY
0X000
0X1FF
GOTO MAIN1
0X001
MAIN1
0X040
0X080
CALIBRATION VALUE
RESET VECTOR
MAIN1 ROUTINE
UNPROGRAMMED
UNPROGRAMMED
LEGEND: XX = CALIBRATION VALUE
2000 Microchip Technology Inc. Preliminary DS91017B-page 2-5
TB017
EXAMPLE 2: LOCATION OF THE SECOND MAIN ROUTINE AND IT INTERRUPT VECTOR
(AFTER SECOND PROGRAMMING)
MOVLW XX
MOVWF OSCAL
PROGRAM MEMORY
0X000
0X1FF
NOP
0X001
MAIN1
0X040
0X080
CALIBRATION VALUE
RESET VECTOR
MAIN1 ROUTINE
GOTO MAIN2
MAIN2
MAIN2 ROUTINE
0X10E
0X136
UNPROGRAMMED
UNPROGRAMMED
0X002
LEGEND: XX = CALIBRATION VALUE
TB017
DS91017B-page 2-6 Preliminary 2000 Microchip Technology Inc.
Since the program memory of the PIC12C5XX devices
is organized in 256 x 12 word pages, placement of such
information as look-up tables and CALL instructions
must be taken into account. For further information,
please refer to application note AN581, Implementing
Long Calls and application note AN556, Implementing
a Table Read.
CONCLUSION
Microchip Technology Inc. is committed to supporting
your ICSP needs by providing you with our many years
of experience and expertise in developing in-circuit sys-
tem programming solutions. Anyone can create a reli-
able in-circuit system programming station by coupling
our background with some forethought to the circuit
design and programmer selection issues previously
mentioned. Your local Microchip representative is avail-
able to answer any questions you have about the
requirements for ICSP.
2000 Microchip Technology Inc. Preliminary DS91017B-page 2-7
TB017
APPENDIX A: SAMPLE DRIVER BOARD SCHEMATIC
R6
1
V
PP
_OUT
TO CIRCUIT
3
2 1
4
1U1A
TLE2144A
R9
100
R9
100
V
CC
Q1
2N3906
R10
100
R2
33k
5
6 7
U1B
TLE2144A
V
CC
V
CC
15V
EXTERNAL POWER SUPPLY
R12
100k
V
PP
_IN
FROM
PROGRAMMER
C1
1NF
D1
12.7V
Q2
2N2222
R13
5k
Q3
2N3906
C3
0.1µF
V
DD
_OUT
R15
1TO CIRCUIT
C6
0.1µF
10
9 8
U1C
TLE2144A
V
CC
R18
100
R17
100
Q4
2N2222
R22
5k
R19
100
C4
1NF
D2
6.2V
V
DD
_IN
12
13 14
U1D
TLE2144A
R4
10k
R21
100k
FROM
PROGRAMMER
GP1_IN
GND_IN GND_OUT
FROM
PROGRAMMER
FROM
PROGRAMMER
TO CIRCUIT
GP1_OUT GP0_IN
FROM
PROGRAMMER
TO CIRCUIT
GP0_OUT
TO CIRCUIT
Note: The driver board design MUST be tested in the user’s
application to determine the effects of the applications
circuit on the programming signals timing. Changes
may be required if the application places a significant
load on V
DD
, V
PP
, GP0 or GP1.
*see text in technical brief.
*see text in technical brief.
TB017
DS91017B-page 2-8 Preliminary 2000 Microchip Technology Inc.
NOTES:
2000 Microchip Technology Inc. Preliminary DS91013B-page 2-9
TB013
INTRODUCTION
In-Circuit Serial Programming™ (ICSP) is a great way
to reduce your inventory overhead and time-to-market
for your product. By assembling your product with a
blank Microchip microcontroller (MCU), you can stock
one design. When an order has been placed, these
units can be programmed with the latest revision of
firmware, tested, and shipped in a very short time. This
method also reduces scrapped inventory due to old
firmware revisions. This type of manufacturing system
can also facilitate quick turnarounds on custom orders
for your product.
Most people would think to use ICSP with PICmicro®
OTP MCUs only on an assembly line where the device
is programmed once. However, there is a method by
which an OTP device can be programmed several
times depending on the size of the firmware. This
method, explained later, provides a way to field
upgrade your firmware in a way similar to EEPROM- or
Flash-based devices.
HOW DOES ICSP WORK?
Now that ICSP appeals to you, what steps do you take
to implement it in your application? There are three
main components of an ICSP system: Application
Circuit, Programmer and Programming Environment.
Application Circuit
The application circuit must be designed to allow all the
programming signals to be directly connected to the
PICmicro MCU. Figure 1 shows a typical circuit that is
a starting point for when designing with ICSP. The
application must compensate for the following issues:
1. Isolation of the MCLR/VPP pin from the rest of
the circuit.
2. Isolation of pins RB6 and RB7 from the rest of
the circuit.
3. Capacitance on each of the VDD, MCLR/VPP,
RB6, and RB7 pins.
4. Minimum and maximum operating voltage for
VDD.
5. PICmicro Oscillator.
6. Interface to the programmer.
The MCLR/VPP pin is normally connected to an RC cir-
cuit. The pull-up resistor is tied to VDD and a capacitor
is tied to ground. This circuit can affect the operation of
ICSP depending on the size of the capacitor. It is, there-
fore, recommended that the circuit in Figure 1 be used
when an RC is connected to MCLR/VPP. The diode
should be a Schottky-type device. Another issue with
MCLR/VPP is that when the PICmicro MCU device is
programmed, this pin is driven to approximately 13V
and also to ground. Therefore, the application circuit
must be isolated from this voltage provided by the
programmer.
FIGURE 1: TYPICAL APPLICATION CIRCUIT
Author: Rodger Richey
Microchip Technology Inc.
Application PCB
PIC16CXXX
MCLR/Vpp
Vdd
Vss
RB7
RB6
Vdd Vdd
To application circuit
Isolation circuits
ICSP Connector
How to Implement ICSP™ Using PIC16CXXX OTP MCUs
TB013
DS91013B-page 2-10 Preliminary 2000 Microchip Technology Inc.
Pins RB6 and RB7 are used by the PICmicro MCU for
serial programming. RB6 is the clock line and RB7 is
the data line. RB6 is driven by the programmer. RB7 is
a bidirectional pin that is driven by the programmer
when programming, and driven by the PICmicro MCU
when verifying. These pins must be isolated from the
rest of the application circuit so as not to affect the sig-
nals during programming. You must take into consider-
ation the output impedance of the programmer when
isolating RB6 and RB7 from the rest of the circuit. This
isolation circuit must account for RB6 being an input on
the PICmicro MCU, and for RB7 being bidirectional
(can be driven by both the PICmicro MCU and the pro-
grammer). For instance, PRO MATE® II has an output
impedance of 1k¾. If the design permits, these pins
should not be used by the application. This is not the
case with most applications so it is recommended that
the designer evaluate whether these signals need to be
buffered. As a designer, you must consider what type of
circuitry is connected to RB6 and RB7 and then make
a decision on how to isolate these pins. Figure 1 does
not show any circuitry to isolate RB6 and RB7 on the
application circuit because this is very application
dependent.
The total capacitance on the programming pins affects
the rise rates of these signals as they are driven out of
the programmer. Typical circuits use several hundred
microfarads of capacitance on VDD which helps to
dampen noise and ripple. However, this capacitance
requires a fairly strong driver in the programmer to
meet the rise rate timings for VDD. Most programmers
are designed to simply program the PICmicro MCU
itself and don’t have strong enough drivers to power the
application circuit. One solution is to use a driver board
between the programmer and the application circuit.
The driver board requires a separate power supply that
is capable of driving the VPP and VDD pins with the
correct rise rates and should also provide enough cur-
rent to power the application circuit. RB6 and RB7 are
not buffered on this schematic but may require buffer-
ing depending upon the application. A sample driver
board schematic is shown in Appendix A.
The Microchip programming specification states that
the device should be programmed at 5V. Special con-
siderations must be made if your application circuit
operates at 3V only. These considerations may include
totally isolating the PICmicro MCU during program-
ming. The other issue is that the device must be verified
at the minimum and maximum voltages at which the
application circuit will be operating. For instance, a bat-
tery operated system may operate from three 1.5V
cells giving an operating voltage range of 2.7V to 4.5V.
The programmer must program the device at 5V and
must verify the program memory contents at both 2.7V
and 4.5V to ensure that proper programming margins
have been achieved. This ensures the PICmicro MCU
option over the voltage range of the system.
This final issue deals with the oscillator circuit on the
application board. The voltage on MCLR/VPP must rise
to the specified program mode entry voltage before the
device executes any code. The crystal modes available
on the PICmicro MCU are not affected by this issue
because the Oscillator Start-up Timer waits for 1024
oscillations before any code is executed. However, RC
oscillators do not require any startup time and, there-
fore, the Oscillator Startup Timer is not used. The pro-
grammer must drive MCLR/VPP to the program mode
entry voltage before the RC oscillator toggles four
times. If the RC oscillator toggles four or more times,
the program counter will be incremented to some value
X. Now when the device enters programming mode,
the program counter will not be zero and the program-
mer will start programming your code at an offset of X.
There are several alternatives that can compensate for
a slow rise rate on MCLR/VPP. The first method would
be to not populate the R, program the device, and then
insert the R. The other method would be to have the
programming interface drive the OSC1 pin of the
PICmicro MCU to ground while programming. This will
prevent any oscillations from occurring during program-
ming.
Now all that is left is how to connect the application cir-
cuit to the programmer. This depends a lot on the
programming environment and will be discussed in that
section.
Programmer
The second consideration is the programmer.
PIC16CXXX MCUs only use serial programming and
therefore all programmers supporting these devices
will support ICSP. One issue with the programmer is the
drive capability. As discussed before, it must be able to
provide the specified rise rates on the ICSP signals and
also provide enough current to power the application
circuit. Appendix A shows an example driver board.
This driver schematic does not show any buffer circuitry
for RB6 and RB7. It is recommended that an evaluation
be performed to determine if buffering is required.
Another issue with the programmer is what VDD levels
are used to verify the memory contents of the PICmicro
MCU. For instance, the PRO MATE II verifies program
memory at the minimum and maximum VDD levels for
the specified device and is therefore considered a pro-
duction quality programmer. On the other hand, the
PICSTART® Plus only verifies at 5V and is for prototyp-
ing use only. The Microchip programming specifica-
tions state that the program memory contents should
be verified at both the minimum and maximum VDD lev-
els that the application circuit will be operating. This
implies that the application circuit must be able to han-
dle the varying VDD voltages.
Note: The driver board design MUST be tested
in the user’s application to determine the
effects of the application circuit on the
programming signals timing. Changes
may be required if the application places
a significant load on VDD, VPP, RB6 OR
RB7.
2000 Microchip Technology Inc. Preliminary DS91013B-page 2-11
TB013
There are also several third party programmers that are
available. You should select a programmer based on
the features it has and how it fits into your programming
environment. The Microchip Development Systems
Ordering Guide (DS30177) provides detailed informa-
tion on all our development tools. The Microchip Third
Party Guide (DS00104) provides information on all of
our third party tool developers. Please consult these
two references when selecting a programmer. Many
options exist including serial or parallel PC host con-
nection, stand-alone operation, and single or gang pro-
grammers. Some of the third party developers include
Advanced Transdata Corporation, BP Microsystems,
Data I/O, Emulation Technology and Logical Devices.
Programming Environment
The programming environment will affect the type of
programmer used, the programmer cable length, and
the application circuit interface. Some programmers
are well suited for a manual assembly line while others
are desirable for an automated assembly line. You may
want to choose a gang programmer to program multiple
systems at a time.
The physical distance between the programmer and
the application circuit affects the load capacitance on
each of the programming signals. This will directly
affect the drive strength needed to provide the correct
signal rise rates and current. This programming cable
must also be as short as possible and properly
terminated and shielded, or the programming signals
may be corrupted by ringing or noise.
Finally, the application circuit interface to the program-
mer depends on the size constraints of the application
circuit itself and the assembly line. A simple header can
be used to interface the application circuit to the pro-
grammer. This might be more desirable for a manual
assembly line where a technician plugs the
programmer cable into the board. A different method is
the use of spring loaded test pins (commonly referred
to as pogo pins). The application circuit has pads on
the board for each of the programming signals. Then
there is a fixture that has pogo pins in the same config-
uration as the pads on the board. The application circuit
or fixture is moved into position such that the pogo pins
come into contact with the board. This method might be
more suitable for an automated assembly line.
After taking into consideration the issues with the appli-
cation circuit, the programmer, and the programming
environment, anyone can build a high quality, reliable
manufacturing line based on ICSP.
Other Benefits
ICSP provides other benefits, such as calibration and
serialization. If program memory permits, it would be
cheaper and more reliable to store calibration con-
stants in program memory instead of using an external
serial EEPROM. For example, your system has a ther-
mistor which can vary from one system to another.
Storing some calibration information in a table format
allows the microcontroller to compensate in software
for external component tolerances. System cost can be
reduced without affecting the required performance of
the system by using software calibration techniques.
But how does this relate to ICSP? The PICmicro MCU
has already been programmed with firmware that per-
forms a calibration cycle. The calibration data is trans-
ferred to a calibration fixture. When all calibration data
has been transferred, the fixture places the PICmicro
MCU in programming mode and programs the
PICmicro MCU with the calibration data. Application
note AN656, In-Circuit Serial Programming of Calibra-
tion Parameters Using a PICmicro Microcontroller,
shows exactly how to implement this type of calibration
data programming.
The other benefit of ICSP is serialization. Each individ-
ual system can be programmed with a unique or ran-
dom serial number. One such application of a unique
serial number would be for security systems. A typical
system might use DIP switches to set the serial num-
ber. Instead, this number can be burned into program
memory, thus reducing the overall system cost and low-
ering the risk of tampering.
Field Programming of PICmicro OTP MCUs
An OTP device is not normally capable of being
reprogrammed, but the PICmicro MCU architecture
gives you this flexibility provided the size of your firm-
ware is at least half that of the desired device and the
device is not code protected. If your target device does
not have enough program memory, Microchip provides
a wide spectrum of devices from 0.5K to 8K program
memory with the same set of peripheral features that
will help meet the criteria.
The PIC16CXXX microcontrollers have two vectors,
reset and interrupt, at locations 0x0000 and 0x0004.
When the PICmicro MCU encounters a reset or inter-
rupt condition, the code located at one of these two
locations in program memory is executed. The first list-
ing of Example 1 shows the code that is first pro-
grammed into the PICmicro MCU. The second listing of
Example 1 shows the code that is programmed into the
PICmicro MCU for the second time.
TB013
DS91013B-page 2-12 Preliminary 2000 Microchip Technology Inc.
EXAMPLE 1: PROGRAMMING CYCLE LISTING FILES
First Program Cycle Second Program Cycle
_________________________________________________________________________________________
Prog Opcode Assembly |Prog Opcode Assembly
Mem Instruction |Mem Instruction
-----------------------------------------------------------------------------------------
0000 2808 goto Main ;Main loop |0000 0000 nop
0001 3FFF <blank> ;at 0x0008 |0001 2860 goto Main ;Main now
0002 3FFF <blank> |0002 3FFF <blank> ;at 0x0060
0003 3FFF <blank> |0003 3FFF <blank>
0004 2848 goto ISR ;ISR at |0004 0000 nop
0005 3FFF <blank> ;0x0048 |0005 28A8 goto ISR ;ISR now at
0006 3FFF <blank> |0006 3FFF <blank> ;0x00A8
0007 3FFF <blank> |0007 3FFF <blank>
0008 1683 bsf STATUS,RP0 | 0008 1683 bsf STATUS,RP0
0009 3007 movlw 0x07 |0009 3007 movlw 0x07
000A 009F movwf ADCON1 |000A 009F movwf ADCON1
. | .
. | .
. | .
0048 1C0C btfss PIR1,RBIF | 0048 1C0C btfss PIR1,RBIF
0049 284E goto EndISR |0049 284E goto EndISR
004A 1806 btfsc PORTB,0 |004A 1806 btfsc PORTB,0
. | .
. | .
. | .
0060 3FFF <blank> |0060 1683 bsf STATUS,RP0
0061 3FFF <blank> |0061 3005 movlw 0x05
0062 3FFF <blank> |0062 009F movwf ADCON1
. | .
. | .
. | .
00A8 3FFF <blank> |00A8 1C0C btfss PIR1,RBIF
00A9 3FFF <blank> |00A9 28AE goto EndISR
00AA 3FFF <blank> |00AA 1806 btfsc PORTB,0
. | .
. | .
. | .
-----------------------------------------------------------------------------------------
2000 Microchip Technology Inc. Preliminary DS91013B-page 2-13
TB013
The example shows that to program the PICmicro MCU
a second time the memory location 0x0000, originally
goto Main (0x2808), is reprogrammed to all 0’s which
happens to be a nop instruction. This location cannot
be reprogrammed to the new opcode (0x2860)
because the bits that are 0’s cannot be reprogrammed
to 1’s, only bits that are 1’s can be reprogrammed to
0’s. The next memory location 0x0001 was originally
blank (all 1’s) and now becomes a goto Main
(0x2860). When a reset condition occurs, the PICmicro
MCU executes the instruction at location 0x0000 which
is the nop, a completely benign instruction, and then
executes the goto Main to start the execution of code.
The example also shows that all program memory loca-
tions after 0x005A are blank in the original program so
that the second time the PICmicro MCU is pro-
grammed, the revised code can be programmed at
these locations. The same descriptions can be given
for the interrupt vector at location 0x0004.
This method changes slightly for PICmicro MCUs with
>2K words of program memory. Each of the goto
Main and goto ISR instructions are replaced by the
following code segments due to paging on devices with
>2K words of program memory.
movlw <page> movlw <page>
movwf PCLATH movwf PCLATH
goto Main goto ISR
Now your one time programmable PICmicro MCU is
exhibiting more EEPROM- or Flash-like qualities.
CONCLUSION
Microchip Technology Inc. is committed to supporting
your ICSP needs by providing you with our many years
of experience and expertise in developing ICSP
solutions. Anyone can create a reliable ICSP program-
ming station by coupling our background with some
forethought to the circuit design and programmer
selection issues previously mentioned. Your local
Microchip representative is available to answer any
questions you have about the requirements for ICSP.
TB013
DS91013B-page 2-14 Preliminary 2000 Microchip Technology Inc.
APPENDIX A: SAMPLE DRIVER BOARD SCHEMATIC
R6
1
V
PP
_OUT
TO CIRCUIT
3
2 1
4
1U1A
TLE2144A
R9
100
R9
100
V
CC
Q1
2N3906
R10
100
R2
33k
5
6 7
U1B
TLE2144A
V
CC
V
CC
15V
EXTERNAL POWER SUPPLY
R12
100k
V
PP
_IN
FROM
PROGRAMMER
C1
1NF
D1
12.7V
Q2
2N2222
R13
5k
Q3
2N3906
C3
0.1µF
V
DD
_OUT
R15
1TO CIRCUIT
C6
0.1µF
10
9 8
U1C
TLE2144A
V
CC
R18
100
R17
100
Q4
2N2222
R22
5k
R19
100
C4
1NF
D2
6.2V
V
DD
_IN
12
13 14
U1D
TLE2144A
R4
10k
R21
100k
FROM
PROGRAMMER
RB6_IN
GND_IN GND_OUT
FROM
PROGRAMMER
FROM
PROGRAMMER
TO CIRCUIT
RB6_OUT RB7_IN
FROM
PROGRAMMER
TO CIRCUIT
RB7_OUT
TO CIRCUIT
Note: The driver board design MUST be tested in the user’s
application to determine the effects of the application
circuit on the programming signals timing. Changes
may be required if the application places a significant
load on Vdd, Vpp, RB6 or RB7.
*see text in technical brief.
*see text in technical brief.
2000 Microchip Technology Inc. Preliminary DS91015A-page 2-15
TB015
INTRODUCTION
PIC17CXXX microcontroller (MCU) devices can be
serially programmed using an RS-232 or equivalent
serial interface. As shown in Figure 2, using just three
pins, the PIC17CXXX can be connected to an external
interface and programmed. In-Circuit Serial Program-
ming (ICSP™) allows for a greater flexibility in an appli-
cation as well as a faster time to market for the user's
product.
This technical brief will demonstrate the practical
aspects associated with ICSP using the PIC17CXXX. It
will also demonstrate some key capabilities of OTP
devices when used in conjunction with ICSP.
Implementation
The PIC17CXXX devices have special instructions,
which enables the user to program and read the
PIC17CXXX's program memory. The instructions are
TABLWT and TLWT which implement the program mem-
ory write operation and TABLRD and TLRD which per-
form the program memory read operation. For more
details, please check the In-Circuit Serial Programming
for PIC17CXXX OTP Microcontrollers Specification
(DS30273), PIC17C4X data sheet (DS30412) and
PIC17C75X data sheet (DS30264).
When doing ICSP, the PIC17CXXX runs a boot code,
which configures the USART port and receives data
serially through the RX line. This data is then pro-
grammed at the address specified in the serial data
string. A high voltage (about 13V) is required for the
EPROM cell to get programmed, and this is usually
supplied by the programming header as shown in
Figure 2 and Figure 3. The PIC17CXXX's boot code
enables and disables the high voltage line using a ded-
icated I/O line.
FIGURE 2: PIC17CXXX IN-CIRCUIT SERIAL PROGRAMMING USING TABLE WRITE
INSTRUCTIONS
Author: Stan D’Souza
Microchip Technology Inc.
PIC17CXXX
Data
Memory Program
Memory
Data L
Data H
Boot
Code
USART Level Converter
In-Circuit
Programming
Connector
I/O 13V Enable
SYSTEM BOARD
VPP
13V
RX
TX
Data H:Data L
How to Implement ICSP™ Using PIC17CXXX OTP MCUs
TB015
DS91015A-page 2-16 Preliminary 2000 Microchip Technology Inc.
FIGURE 3: PIC17CXXX IN-CIRCUIT SERIAL PROGRAMMING SCHEMATIC
ICSP Boot Code
The boot code is normally programmed, into the
PIC17CXXX device using a PRO MATE® or
PICSTART® Plus or any third party programmer. As
depicted in the flowchart in Figure 5, on power-up, or a
reset, the program execution always vectors to the boot
code. The boot code is normally located at the bottom
of the program memory space e.g. 0x700 for a
PIC17C42A (Figure 4).
Several methods could be used to reset the
PIC17CXXX when the ICSP header is connected to the
system board. The simplest method, as shown in
Figure 3, is to derive the system 5V, from the 13V sup-
plied by the ICSP header. It is quite common in manu-
facturing lines, to have system boards programmed
with only the boot code ready and available for testing,
calibration or final programming. The ICSP header
would thus supply the 13V to the system and this 13V
would then be stepped down to supply the 5V required
to power the system. Please note that the 13V supply
should have enough drive capability to supply power to
the system as well as maintain the programming volt-
age of 13V.
The first action of the boot code (as shown in flowchart
Figure 5) is to configure the USART to a known baud
rate and transmit a request sequence to the ICSP host
system. The host immediately responds with an
acknowledgment of this request. The boot code then
gets ready to receive ICSP data. The host starts send-
ing the data and address byte sequences to the
PIC17CXXX. On receiving the address and data
information, the 16-bit address is loaded into the
TBLPTR registers and the 16-bit data is loaded into the
TABLAT registers. The RA2 pin is driven low to enable
13V at MCLR. The PIC17CXXX device then executes
a table write instruction. This instruction in turn causes
a long write operation, which disables further code exe-
cution. Code execution is resumed when an internal
interrupt occurs. This delay ensures that the program-
ming pulse width of 1 ms (max.) is met. Once a location
is written, RA2 is driven high to disable further writes
and a verify operation is done using the Table read
instruction. If the result is good, an acknowledge is sent
to the host. This process is repeated till all desired loca-
tions are programmed.
In normal operation, when the ICSP header is not con-
nected, the boot code would still execute and the
PIC17CXXX would send out a request to the host.
However it would not get a response from the host, so
it would abort the boot code and start normal code
execution.
FIGURE 4: BOOT CODE EXAMPLE FOR
PIC17C42A
PIC17CXXX
Vdd
MCLR
RA2
RX
Vss
+5V
MAX232
2N3905 13V
+5V
Serial Port TX
Serial Port RX
TX
7805
Programming Header
Reset Vector
Boot Code
Program Memory
0x700
0x7FF
2000 Microchip Technology Inc. Preliminary DS91015A-page 2-17
TB015
FIGURE 5: FLOWCHART FOR ICSP BOOT CODE
Start
Received Host’s
Configure USART
and send request
Goto Boot Code
Prepare to receive
ICSP data
Do Table Write
operation
Received Address
and Data info?
Last Data/Address
Signal Programming
Error
END
sequence?
ACK?
Time-out complete?
Start Code
Execution
Interrupt?
Read Program
Location
Program location
verified correctly?
No
Ye s
No
Ye s
No
Ye s
No
Ye s
Ye s
No
Ye s
No
TB015
DS91015A-page 2-18 Preliminary 2000 Microchip Technology Inc.
USING THE ICSP FEATURE ON
PIC17CXXX OTP DEVICES
The ICSP feature is a very powerful tool when used in
conjunction with OTP devices.
Saving Calibration Information Using ICSP
One key use of ICSP is to store calibration constants or
parameters in program memory. It is quite common to
interface a PIC17CXXX device to a sensor. Accurate,
pre-calibrated sensors can be used, but they are more
expensive and have long lead times. Uncalibrated sen-
sors on the other hand are inexpensive and readily
available. The only caveat is that these sensors have to
be calibrated in the application. Once the calibration
constants have been determined, they would be unique
to a given system, so they have to be saved in program
memory. These calibration parameters/constants can
then be retrieved later during program execution and
used to improve the accuracy of low cost un-calibrated
sensors. ICSP thus offers a cost reduction path for the
end user in the application.
Saving Field Calibration Information Using
ICSP
Sensors typically tend to drift and lose calibration over
time and usage. One expensive solution would be to
replace the sensor with a new one. A more cost effec-
tive solution however, is to re-calibrated the system and
save the new calibration parameter/constants into the
PIC17CXXX devices using ICSP. The user program
however has to take into account certain issues:
1. Un-programmed or blank locations have to be
reserved at each calibration constant location in
order to save new calibration parameters/con-
stants.
2. The old calibration parameters/constants are all
programmed to 0, so the user program will have
to be “intelligent” and differentiate between blank
(0xFFFF), zero (0x0000), and programmed locations.
Figure 6 shows how this can be achieved.
Programming Unique Serial Numbers Using
ICSP
There are applications where each system needs to
have a unique and sometimes random serial number.
Example: security devices. One common solution is to
have a set of DIP switches which are then set to a
unique value during final test. A more cost effective
solution however would be to program unique serial
numbers into the device using ICSP. The user applica-
tion can thus eliminate the need for DIP switches and
subsequently reduce the cost of the system.
FIGURE 6: FIELD CALIBRATION USING ICSP
Parameter 1.1
0xFFFF
0xFFFF
0xFFFF
Parameter 2.1
0xFFFF
0xFFFF
0xFFFF
Factory Settings
0x0000
Parameter 1.2
0xFFFF
0xFFFF
0x0000
Parameter 2.2
0xFFFF
0xFFFF
Field Calibrate #1
0x0000
0x0000
Parameter 1.3
0xFFFF
0x0000
0x0000
Parameter 2.3
0xFFFF
Field Calibrate #2
2000 Microchip Technology Inc. Preliminary DS91015A-page 2-19
TB015
Code Updates in the Field Using ICSP
With fast time to market it is not uncommon to see
application programs which need to be updated or cor-
rected for either enhancements or minor errors/bugs. If
ROM parts were used, updates would be impossible
and the product would either become outdated or
recalled from the field. A more cost effective solution
is to use OTP devices with ICSP and program them in
the field with the new updates. Figure 7 shows an
example where the user has allowed for one field
update to his program.
Here are some of the issues which need to be
addressed:
1. The user has to reserve sufficient blank memory
to fit his updated code.
2. At least one blank location needs to be saved at
the reset vector as well as for all the interrupts.
3. Program all the old “goto” locations (located at
the reset vector and the interrupts vectors) to 0
so that these instructions execute as NOPs.
4. Program new “goto” locations (at the reset vec-
tor and the interrupt vectors) just below the old
“goto” locations.
5. Finally, program the new updated code in the
blank memory space.
CONCLUSION
ICSP is a very powerful feature available on the
PIC17CXXX devices. It offers tremendous design flex-
ibility to the end user in terms of saving calibration con-
stants and updating code in final production as well as
in the field, thus helping the user design a low-cost and
fast time-to-market product.
FIGURE 7: CODE UPDATES USING ICSP
Goto Boot
Goto Main1
0xFFFF
0xFFFF
Production Program
0x0000
Main1
Main
Boot
Goto Main
Goto Boot
0x0000
Goto Main2
0xFFFF
Code Update #1
Main1
Main
Boot
Goto Main
Main2
0x0000
TB015
DS91015A-page 2-20 Preliminary 2000 Microchip Technology Inc.
NOTES:
2000 Microchip Technology Inc. DS91016B-page 2-21
TB016
INTRODUCTION
In-Circuit Serial Programming™ (ICSP) with
PICmicro® FLASH microcontrollers (MCU) is not only a
great way to reduce your inventory overhead and time-
to-market for your product, but also to easily provide
field upgrades of firmware. By assembling your product
with a Microchip FLASH-based MCU, you can stock the
shelf with one system. When an order has been placed,
these units can be programmed with the latest revision
of firmware, tested, and shipped in a very short time.
This type of manufacturing system can also facilitate
quick turnarounds on custom orders for your product.
You don’t have to worry about scrapped inventory
because of the FLASH-based program memory. This
gives you the advantage of upgrading the firmware at
any time to fix those “features” that pop up from time to
time.
HOW DOES ICSP WORK?
Now that ICSP appeals to you, what steps do you take
to implement it in your application? There are three
main components of an ICSP system.
These are the: Application Circuit, Programmer and
Programming Environment.
Application Circuit
The application circuit must be designed to allow all the
programming signals to be directly connected to the
PICmicro MCUs. Figure 1 shows a typical circuit that is
a starting point for when designing with ICSP. The
application must compensate for the following issues:
1. Isolation of the MCLR/VPP pin from the rest of
the circuit.
2. Isolation of pins RB6 and RB7 from the rest of
the circuit.
3. Capacitance on each of the VDD, MCLR/VPP,
RB6, and RB7 pins.
4. Minimum and maximum operating voltage for
VDD.
5. PICmicro Oscillator.
6. Interface to the programmer.
The MCLR/VPP pin is normally connected to an RC cir-
cuit. The pull-up resistor is tied to VDD and a capacitor
is tied to ground. This circuit can affect the operation of
ICSP depending on the size of the capacitor. It is, there-
fore, recommended that the circuit in Figure 1 be used
when an RC is connected to MCLR/VPP. The diode
should be a Schottky-type device. Another issue with
MCLR/VPP is that when the PICmicro MCU device is
programmed, this pin is driven to approximately 13V
and also to ground. Therefore, the application circuit
must be isolated from this voltage provided by the
programmer.
FIGURE 1: TYPICAL APPLICATION CIRCUIT
Author: Rodger Richey
Microchip Technology Inc.
Application PCB
PIC16F8X
MCLR/VPP
Vdd
Vss
RB7
RB6
Vdd Vdd
To application circuit
Isolation circuits
ICSP Connector
How to Implement ICSP™ Using PIC16F8X FLASH MCUs
PICmicro, PRO MATE, and PICSTART are registered trademarks of Microchip Technology Inc.
In-Circuit Serial Programming and ICSP are trademarks of Microchip Technology Inc.
TB016
DS91016B-page 2-22 2000 Microchip Technology Inc.
Pins RB6 and RB7 are used by the PICmicro MCU for
serial programming. RB6 is the clock line and RB7 is
the data line. RB6 is driven by the programmer. RB7 is
a bidirectional pin that is driven by the programmer
when programming, and driven by the PICmicro MCU
when verifying. These pins must be isolated from the
rest of the application circuit so as not to affect the sig-
nals during programming. You must take into consider-
ation the output impedance of the programmer when
isolating RB6 and RB7 from the rest of the circuit. This
isolation circuit must account for RB6 being an input on
the PICmicro MCU and for RB7 being bidirectional (can
be driven by both the PICmicro MCU and the program-
mer). For instance, PRO MATE® II has an output
impedance of 1k¾. If the design permits, these pins
should not be used by the application. This is not the
case with most applications so it is recommended that
the designer evaluate whether these signals need to be
buffered. As a designer, you must consider what type of
circuitry is connected to RB6 and RB7 and then make
a decision on how to isolate these pins. Figure 1 does
not show any circuitry to isolate RB6 and RB7 on the
application circuit because this is very application
dependent.
The total capacitance on the programming pins affects
the rise rates of these signals as they are driven out of
the programmer. Typical circuits use several hundred
microfarads of capacitance on VDD which helps to
dampen noise and ripple. However, this capacitance
requires a fairly strong driver in the programmer to
meet the rise rate timings for VDD. Most programmers
are designed to simply program the PICmicro MCU
itself and don’t have strong enough drivers to power the
application circuit. One solution is to use a driver board
between the programmer and the application circuit.
The driver board requires a separate power supply that
is capable of driving the VPP and VDD pins with the cor-
rect rise rates and should also provide enough current
to power the application circuit. RB6 and RB7 are not
buffered on this schematic but may require buffering
depending upon the application. A sample driver board
schematic is shown in Appendix A.
The Microchip programming specification states that
the device should be programmed at 5V. Special con-
siderations must be made if your application circuit
operates at 3V only. These considerations may include
totally isolating the PICmicro MCU during program-
ming. The other issue is that the device must be verified
at the minimum and maximum voltages at which the
application circuit will be operating. For instance, a bat-
tery operated system may operate from three 1.5V
cells giving an operating voltage range of 2.7V to 4.5V.
The programmer must program the device at 5V and
must verify the program memory contents at both 2.7V
and 4.5V to ensure that proper programming margins
have been achieved. This ensures the PICmicro MCU
option over the voltage range of the system.
This final issue deals with the oscillator circuit on the
application board. The voltage on MCLR/VPP must rise
to the specified program mode entry voltage before the
device executes any code. The crystal modes available
on the PICmicro MCU are not affected by this issue
because the Oscillator Start-up Timer waits for 1024
oscillations before any code is executed. However, RC
oscillators do not require any startup time and, there-
fore, the Oscillator Startup Timer is not used. The pro-
grammer must drive MCLR/VPP to the program mode
entry voltage before the RC oscillator toggles four
times. If the RC oscillator toggles four or more times,
the program counter will be incremented to some value
X. Now when the device enters programming mode,
the program counter will not be zero and the program-
mer will start programming your code at an offset of X.
There are several alternatives that can compensate for
a slow rise rate on MCLR/VPP. The first method would
be to not populate the R, program the device, and then
insert the R. The other method would be to have the
programming interface drive the OSC1 pin of the
PICmicro MCU to ground while programming. This will
prevent any oscillations from occurring during program-
ming.
Now all that is left is how to connect the application cir-
cuit to the programmer. This depends a lot on the
programming environment and will be discussed in that
section.
Programmer
The second consideration is the programmer.
PIC16F8X MCUs only use serial programming and
therefore all programmers supporting these devices
will support ICSP. One issue with the programmer is the
drive capability. As discussed before, it must be able to
provide the specified rise rates on the ICSP signals and
also provide enough current to power the application
circuit. Appendix A shows an example driver board.
This driver schematic does not show any buffer circuitry
for RB6 and RB7. It is recommended that an evalua-
tion be performed to determine if buffering is required.
Another issue with the programmer is what VDD levels
are used to verify the memory contents of the PICmicro
MCU. For instance, the PRO MATE II verifies program
memory at the minimum and maximum VDD levels for
the specified device and is therefore considered a pro-
duction quality programmer. On the other hand, the
PICSTART® Plus only verifies at 5V and is for prototyp-
ing use only. The Microchip programming specifica-
tions state that the program memory contents should
be verified at both the minimum and maximum VDD lev-
els that the application circuit will be operating. This
implies that the application circuit must be able to han-
dle the varying VDD voltages.
Note: The driver board design MUST be tested
in the user’s application to determine the
effects of the application circuit on the
programming signals timing. Changes
may be required if the application places
a significant load on Vdd, VPP, RB6 or
RB7.
2000 Microchip Technology Inc. DS91016B-page 2-23
TB016
There are also several third party programmers that are
available. You should select a programmer based on
the features it has and how it fits into your programming
environment. The Microchip Development Systems
Ordering Guide (DS30177) provides detailed informa-
tion on all our development tools. The Microchip Third
Party Guide (DS00104) provides information on all of
our third party tool developers. Please consult these
two references when selecting a programmer. Many
options exist including serial or parallel PC host con-
nection, stand-alone operation, and single or gang pro-
grammers. Some of the third party developers include
Advanced Transdata Corporation, BP Microsystems,
Data I/O, Emulation Technology and Logical Devices.
Programming Environment
The programming environment will affect the type of
programmer used, the programmer cable length, and
the application circuit interface. Some programmers
are well suited for a manual assembly line while others
are desirable for an automated assembly line. You may
want to choose a gang programmer to program multiple
systems at a time.
The physical distance between the programmer and
the application circuit affects the load capacitance on
each of the programming signals. This will directly
affect the drive strength needed to provide the correct
signal rise rates and current. This programming cable
must also be as short as possible and properly termi-
nated and shielded or the programming signals may be
corrupted by ringing or noise.
Finally, the application circuit interface to the program-
mer depends on the size constraints of the application
circuit itself and the assembly line. A simple header can
be used to interface the application circuit to the pro-
grammer. This might be more desirable for a manual
assembly line where a technician plugs the
programmer cable into the board. A different method is
the use of spring loaded test pins (commonly referred
to as pogo pins). The application circuit has pads on
the board for each of the programming signals. Then
there is a fixture that has pogo pins in the same config-
uration as the pads on the board. The application circuit
or fixture is moved into position such that the pogo pins
come into contact with the board. This method might be
more suitable for an automated assembly line.
After taking into consideration the issues with the appli-
cation circuit, the programmer, and the programming
environment, anyone can build a high quality, reliable
manufacturing line based on ICSP.
Other Benefits
ICSP provides other benefits, such as calibration and
serialization. If program memory permits, it would be
cheaper and more reliable to store calibration con-
stants in program memory instead of using an external
serial EEPROM. For example, your system has a ther-
mistor which can vary from one system to another.
Storing some calibration information in a table format
allows the microcontroller to compensate in software
for external component tolerances. System cost can be
reduced without affecting the required performance of
the system by using software calibration techniques.
But how does this relate to ICSP? The PICmicro MCU
has already been programmed with firmware that per-
forms a calibration cycle. The calibration data is trans-
ferred to a calibration fixture. When all calibration data
has been transferred, the fixture places the PICmicro
MCU in programming mode and programs the
PICmicro MCU with the calibration data. Application
note AN656, In-Circuit Serial Programming of Calibra-
tion Parameters Using a PICmicro Microcontroller,
shows exactly how to implement this type of calibration
data programming.
The other benefit of ICSP is serialization. Each individ-
ual system can be programmed with a unique or ran-
dom serial number. One such application of a unique
serial number would be for security systems. A typical
system might use DIP switches to set the serial num-
ber. Instead, this number can be burned into program
memory thus reducing the overall system cost and low-
ering the risk of tampering.
Field Programming of FLASH PICmicro MCUs
With the ISP interface circuitry already in place, these
FLASH-based PICmicro MCUs can be easily repro-
grammed in the field. These FLASH devices allow you
to reprogram them even if they are code protected. A
portable ISP programming station might consist of a
laptop computer and programmer. The technician
plugs the ISP interface cable into the application circuit
and downloads the new firmware into the PICmicro
MCU. The next thing you know the system is up and
running without those annoying “bugs”. Another
instance would be that you want to add an additional
feature to your system. All of your current inventory can
be converted to the new firmware and field upgrades
can be performed to bring your installed base of sys-
tems up to the latest revision of firmware.
CONCLUSION
Microchip Technology Inc. is committed to supporting
your ICSP needs by providing you with our many years
of experience and expertise in developing ICSP
solutions. Anyone can create a reliable ICSP program-
ming station by coupling our background with some
forethought to the circuit design and programmer
selection issues previously mentioned. Your local
Microchip representative is available to answer any
questions you have about the requirements for ICSP.
TB016
DS91016B-page 2-24 2000 Microchip Technology Inc.
APPENDIX A: SAMPLE DRIVER BOARD SCHEMATIC
R6
1
V
PP
_OUT
TO CIRCUIT
3
2 1
4
1U1A
TLE2144A
R9
100
R9
100
Vcc
Q1
2N3906
R10
100
R2
33k
5
6 7
U1B
TLE2144A
Vcc
Vcc
15V
EXTERNAL POWER SUPPLY
R12
100k
V
PP
_IN
FROM
PROGRAMMER
C1
1NF
D1
12.7V
Q2
2N2222
R13
5k
Q3
2N3906
C3
0.1mF
V
DD
_OUT
R15
1TO CIRCUIT
C6
0.1mF
10
9 8
U1C
TLE2144A
VccR18
100
R17
100
Q4
2N2222
R22
5k
R19
100
C4
1NF
D2
6.2V
Vdd_IN
12
13 14
U1D
TLE2144A
R4
10k
R21
100k
FROM
PROGRAMMER
RB6_IN
GND_IN GND_OUT
FROM
PROGRAMMER
FROM
PROGRAMMER
TO CIRCUIT
RB6_OUT RB7_IN
from
programmer
TO CIRCUIT
RB7_OUT
To Circuit
Note: The driver board design MUST be tested in the user’s
application to determine the effects of the application
circuit on the programming signals timing. Changes
may be required if the application places a significant
load on Vdd, V
PP
, RB6 or RB7.
*see text in technical brief.
*see text in technical brief.
2000 Microchip Technology Inc. DS30277C-page 3-i
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC12C5XX OTP MCUs .................................................. 3-1
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC12C67X AND PIC12CE67X OTP MCUs ................. 3-15
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC14000 OTP MCUs ................................................... 3-27
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC16C55X OTP MCUs ................................................ 3-39
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC16C6XX/7XX/9XX OTP MCUsS .............................. 3-51
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC17C7XX OTP MCUs ................................................ 3-71
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC18CXXX OTP MCUs ................................................ 3-97
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC16F62X FLASH MCUs .......................................... 3-135
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC16F8X FLASH MCUs ............................................ 3-149
IN-CIRCUIT SERIAL PROGRAMMING FOR PIC16F8XX FLASH MCUs .......................................... 3-165
SECTION 3
PROGRAMMING SPECIFICATIONS
DS30277C-page 3-ii 2000 Microchip Technology Inc.
2000 Microchip Technology Inc. DS30557E-page 3-1
PIC12C5XX
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC12C5XX
The PIC12C5XX can be programmed using a serial
method. Due to this serial programming, the
PIC12C5XX can be programmed while in the user’s
system increasing design flexibility. This programming
specification applies to PIC12C5XX devices in all pack-
ages.
1.1 Hardware Requirements
The PIC12C5XX requires two programmable power
supplies, one for VDD (2.0V to 6.5V recommended) and
one for VPP (12V to 14V). Both supplies should have a
minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC12C5XX allows
programming of user program memory, special loca-
tions used for ID, and the configuration word for the
PIC12C5XX.
Pin Diagram
• PIC12C508 • PIC12C508A • PIC12CE518
• PIC12C509 • PIC12C509A • PIC12CE519
PDIP, SOIC, JW
8
7
6
5
1
2
3
4
VDD
GP5/OSC1/CLKIN
GP4/OSC2/CLKOUT
GP3/MCLR/Vpp
VSS
GP0
GP1
GP2/T0CKI
PIC12C5XX
PIC12C5XXA
PIC12CE5XXA
In-Circuit Serial Programming for PIC12C5XX OTP MCUs
PIC12C5XX
DS30557E-page 3-2 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
The program/verify test mode is entered by holding
pins DB0 and DB1 low while raising MCLR pin from VIL
to VIHH. Once in this test mode the user program mem-
ory and the test program memory can be accessed and
programmed in a serial fashion. The first selected
memory location is the fuses. GP0 and GP1 are
Schmitt trigger inputs in this mode.
Incrementing the PC once (using the increment
address command) selects location 0x000 of the regu-
lar program memory. Afterwards all other memory loca-
tions from 0x001-01FF (PIC12C508/CE518), 0x001-
03FF (PIC12C509/CE519) can be addressed by incre-
menting the PC.
If the program counter has reached the last user pro-
gram location and is incremented again, the on-chip
special EPROM area will be addressed. (See
Figure 2-2 to determine where the special EPROM
area is located for the various PIC12C5XX devices).
2.1 Programming Method
The programming technique is described in the follow-
ing section. It is designed to guarantee good program-
ming margins. It does, however, require a variable
power supply for VCC.
2.1.1 PROGRAMMING METHOD DETAILS
Essentially, this technique includes the following steps:
1. Perform blank check at VDD = VDDmin. Report
failure. The device may not be properly erased.
2. Program location with pulses and verify after
each pulse at VDD = VDDP:
where VDDP = VDD range required during pro-
gramming (4.5V - 5.5V).
a) Programming condition:
VPP = 13.0V to 13.25V
VDD = VDDP = 4.5V to 5.5V
VPP must be ≥ VDD + 7.25V to keep “programming
mode” active.
b) Verify condition:
VDD = VDDP
VPP ≥ VDD + 7.5V but not to exceed 13.25V
If location fails to program after “N” pulses, (sug-
gested maximum program pulses of 8) then report
error as a programming failure.
3. Once location passes “Step 2", apply 11X over
programming, i.e., apply 11 times the number of
pulses that were required to program the loca-
tion. This will guarantee a solid programming
margin. The over programming should be made
“software programmable” for easy updates.
4. Program all locations.
5. Verify all locations (using speed verify mode) at
VDD = VDDmin
6. Verify all locations at VDD = VDDmax
VDDmin is the minimum operating voltage spec. for
the part. VDDmax is the maximum operating volt-
age spec. for the part.
2.1.2 SYSTEM REQUIREMENTS
Clearly, to implement this technique, the most stringent
requirements will be that of the power supplies:
VPP:VPP can be a fixed 13.0V to 13.25V supply. It
must not exceed 14.0V to avoid damage to the pin and
should be current limited to approximately 100mA.
VDD:2.0V to 6.5V with 0.25V granularity. Since this
method calls for verification at different VDD values, a
programmable VDD power supply is needed.
Current Requirement: 40mA maximum
Microchip may release devices in the future with differ-
ent VDD ranges which make it necessary to have a pro-
grammable VDD.
It is important to verify an EPROM at the voltages
specified in this method to remain consistent with
Microchip's test screening. For example, a
PIC12C5XX specified for 4.5V to 5.5V should be
tested for proper programming from 4.5V to 5.5V.
2.1.3 SOFTWARE REQUIREMENTS
Certain parameters should be programmable (and
therefore easily modified) for easy upgrade.
a) Pulse width
b) Maximum number of pulses, present limit 8.
c) Number of over-programming pulses: should be
= (A • N) + B, where N = number of pulses
required in regular programming. In our current
algorithm A = 11, B = 0.
2.2 Programming Pulse Width
Program Memory Cells: When programming one
word of EPROM, a programming pulse width (TPW) of
100µs is recommended.
The maximum number of programming attempts
should be limited to 8 per word.
After the first successful verify, the same location
should be over-programmed with 11X over-program-
ming.
Configuration Word: The configuration word for oscil-
lator selection, WDT (watchdog timer) disable and
code protection, and MCLR enable, requires a pro-
gramming pulse width (TPWF) of 10ms. A series of
100µs pulses is preferred over a single 10ms pulse.
Note: Device must be verified at minimum and
maximum specified operating voltages as
specified in the data sheet.
Note: Any programmer not meeting the programma-
ble VDD requirement and the verify at VDDmax
and VDDmin requirement may only be classi-
fied as “prototype” or “development” program-
mer but not a production programmer.
2000 Microchip Technology Inc. DS30557E-page 3-3
PIC12C5XX
FIGURE 2-1: PROGRAMMING METHOD FLOWCHART
N > 8?
Start
Blank Check
@ VDD = VDDmin
Pass?
Report Possible Erase Failure
Continue Programming
at user’s option
Program 1 Location
@ VPP = 13.0V to 13.25V
VDD = VDDP
N = N + 1
(N = # of program pulses)
Report Programming Failure
Increment PC to point to
next location, N = 0
Apply 11N additional
program pulses
Pass?
All
locations
done?
Verify all locations
@ VDD = VDDmin
Pass? Report verify failure
@ VDDmin
VDD = VDD max.
Verify all locations
@ VDD = VDDmax
Pass? Report verify failure
@ VDDmax
Done
Ye s
No
Ye s
No
No
Ye s
No
Ye s
Ye s
Ye s
No
No
Now program
Configuration Word
Verify Configuration Word
@ VDDmax & VDDmin
PIC12C5XX
DS30557E-page 3-4 2000 Microchip Technology Inc.
FIGURE 2-2: PIC12C5XX SERIES PROGRAM MEMORY MAP IN PROGRAM/VERIFY MODE
Address
(Hex) 000
Bit Number
11 0
NNN
TTT
TTT + 1
TTT + 2
TTT + 3
TTT + 3F
(FFF)
For Customer Use
(4 x 4 bit usable)
For Factory Use
Configuration Word 5 bits
0 0 ID0
0 0 ID1
0 0 ID2
0 0 ID3
User Program Memory
(NNN + 1) x 12 bit
NNN Highest normal EPROM memory address. NNN = 0x1FF for PIC12C508/CE518.
NNN = 0x3FF for PIC12C509/CE519.
TTT Start address of special EPROM area and ID locations.
Note that some versions will have an oscillator calibration value programmed at NNN
2000 Microchip Technology Inc. DS30557E-page 3-5
PIC12C5XX
2.3 Special Memory Locations
The highest address of program memory space is
reserved for the internal RC oscillator calibration value.
This location should not be overwritten except when
this location is blank, and it should be verified, when
programmed, that it is a MOVLW XX instruction.
The ID Locations area is only enabled if the device is in
programming/verify mode. Thus, in normal operation
mode only the memory location 0x000 to 0xNNN will be
accessed and the Program Counter will just roll over
from address 0xNNN to 0x000 when incremented.
The configuration word can only be accessed immedi-
ately after MCLR going from VIL to VHH. The Program
Counter will be set to all ’1’s upon MCLR =VIL. Thus,
it has the value “0xFFF” when accessing the configura-
tion EPROM. Incrementing the Program Counter once
causes the Program Counter to roll over to all '0's.
Incrementing the Program Counter 4K times after reset
(MCLR = VIL) does not allow access to the configura-
tion EPROM.
2.3.1 CUSTOMER ID CODE LOCATIONS
Per definition, the first four words (address TTT to TTT
+ 3) are reserved for customer use. It is recommended
that the customer use only the four lower order bits (bits
0 through 3) of each word and filling the eight higher
order bits with '0's.
A user may want to store an identification code (ID) in
the ID locations and still be able to read this code after
the code protection bit was programmed.
EXAMPLE 2-1: CUSTOMER CODE 0xD1E2
The Customer ID code “0xD1E2” should be stored in
the ID locations 0x200-0x203 like this (PIC12C508/
508A/CE518):
200: 0000 0000 1101
201: 0000 0000 0001
202: 0000 0000 1110
203: 0000 0000 0010
Reading these four memory locations, even with the
code protection bit programmed would still output on
GP0 the bit sequence “1101”, “0001”, “1110”, “0010”
which is “0xD1E2”.
2.4 Program/Verify Mode
The program/verify mode is entered by holding pins
GP1 and GP0 low while raising MCLR pin from VIL to
VIHH (high voltage). Once in this mode the user pro-
gram memory and the configuration memory can be
accessed and programmed in serial fashion. The mode
of operation is serial. GP0 and GP1 are Schmitt Trigger
inputs in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
Note: All other locations in PICmicro® MCU con-
figuration memory are reserved and
should not be programmed.
Note: The MCLR pin should be raised from VIL to
VIHH within 9 ms of VDD rise. This is to
ensure that the device does not have the
PC incremented while in valid operation
range.
PIC12C5XX
DS30557E-page 3-6 2000 Microchip Technology Inc.
2.4.1 PROGRAM/VERIFY OPERATION
The GP1 pin is used as a clock input pin, and the GP0
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (GP1) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin GP0 is required to have a minimum
setup and hold time (see AC/DC specs) with respect to
the falling edge of the clock. Commands that have data
associated with them (read and load) are specified to
have a minimum delay of 1 µs between the command
and the data. After this delay the clock pin is cycled 16
times with the first cycle being a start bit and the last
cycle being a stop bit. Data is also input and output LSB
first. Therefore, during a read operation the LSB will be
transmitted onto pin GP0 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1 µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of the
clock. To allow for decoding of commands and reversal
of data pin configuration, a time separation of at least 1
µs is required between a command and a data word (or
another command).
The commands that are available are listed in Table .
TABLE 2-1: COMMAND MAPPING
Command Mapping (MSB ... LSB) Data
Load Data 000010 0, data(14), 0
Read Data 000100 0, data(14), 0
Increment Address 000110
Begin programming 001000
End Programming 001110
Note: The clock must be disabled during in-circuit programming.
2000 Microchip Technology Inc. DS30557E-page 3-7
PIC12C5XX
2.4.1.1 LOAD DATA
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. Because this is a 12 bit core, the
two msb’s of the data word are ignored. A timing dia-
gram for the load data command is shown in
Figure 5-1.
2.4.1.2 READ DATA
After receiving this command, the chip will transmit
data bits out of the memory currently accessed starting
with the second rising edge of the clock input. The GP0
pin will go into output mode on the second rising clock
edge, and it will revert back to input mode (hi-imped-
ance) after the 16th rising edge. Because this is a 12-
bit core, the two MSB’s of the data are unused and read
as ’0’. A timing diagram of this command is shown in
Figure 5-2.
2.4.1.3 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.4.1.4 BEGIN PROGRAMMING
A load data command must be given before every
begin programming command. Programming of the
appropriate memory (test program memory or user
program memory) will begin after this command is
received and decoded. Programming should be per-
formed with a series of 100µs programming pulses. A
programming pulse is defined as the time between the
begin programming command and the end program-
ming command.
2.4.1.5 END PROGRAMMING
After receiving this command, the chip stops program-
ming the memory (configuration program memory or
user program memory) that it was programming at the
time.
2.5 Programming Algorithm Requires
Variable VDD
The PIC12C5XX uses an intelligent algorithm. The
algorithm calls for program verification at VDDmin as
well as VDDmax. Verification at VDDmin guarantees
good “erase margin”. Verification at VDDmax guaran-
tees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (4.75 - 5.25V).
VDDP =VCC range required during programming.
VDD min. = minimum operating VDD spec for the part.
VDDmax = maximum operating VDD spec for the part.
Programmers must verify the PIC12C5XX at its speci-
fied VDDmax and VDDmin levels. Since Microchip may
introduce future versions of the PIC12C5XX with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
PIC12C5XX
DS30557E-page 3-8 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC12C5XX family members have several config-
uration bits. These bits can be programmed (reads ’0’)
or left unprogrammed (reads ’1’) to select various
device configurations. Figure 3-1 provides an overview
of configuration bits.
FIGURE 3-1: CONFIGURATION WORD BIT MAP
Bit
Number: 11 10 9 8 7 654 321 0
PIC12C5XX ————— — —MCLRE CP WDTE FOSC1 FOSC0
bit 11-5:Reserved, '–' write as '0' for PIC12C5XX
bit 4: MCLRE, Master Clear pin Enable Bit
0 = MCLR internally connected to Vdd
1 = MCLR pin enabled
bit 3: CP, Code Protect Enable Bit
1 = Code Memory Unprotected
0 = Code Memory Protected
bit 2: WDTE, WDT Enable Bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC<1:0>, Oscillator Selection Bit
11: ExtRC oscillator
10: IntRC oscillator
01: XT oscillator
00: LP oscillator
2000 Microchip Technology Inc. DS30557E-page 3-9
PIC12C5XX
4.0 CODE PROTECTION
The program code written into the EPROM can be pro-
tected by writing to the CP bit of the configuration word.
In PIC12C5XX, it is still possible to program and read
locations 0x000 through 0x03F, after code protection.
Once code protection is enabled, all protected seg-
ments read '0's (or “garbage values”) and are pre-
vented from further programming. All unprotected
segments, including ID locations and configuration
word, read normally. These locations can be pro-
grammed.
Once code protection is enabled, all code protected
locations read 0’s. All unprotected segments, including
the internal oscillator calibration value, ID, and configu-
ration word read as normal.
4.1 Embedding Configuration Word and ID Information in the Hex File
TABLE 4-1: CODE PROTECTION
PIC12C508
To code protect:
•(CP enable pattern: XXXXXXXX0XXX)
PIC12C508A
To code protect:
•(CP enable pattern: XXXXXXXX0XXX)
PIC12C509
To code protect:
•(CP enable pattern: XXXXXXXX0XXX))
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read Enabled, Write Enabled Read Enabled, Write Enabled
[0x00:0x3F] Read Enabled, Write Enabled Read Enabled, Write Enabled
[0x40:0x1FF] Read Disabled (all 0’s), Write Disabled Read Enabled, Write Enabled
ID Locations (0x200 : 0x203) Read Enabled, Write Enabled Read Enabled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read enabled, Write Enabled Read enabled, Write Enabled
[0x00:0x3F] Read enabled, Write Enabled Read enabled, Write Enabled
[0x40:0x1FE] Read disabled (all 0’s), Write Disabled Read enabled, Write Enabled
0x1FF Oscillator Calibration Value Read enabled, Write Enabled Read enabled, Write Enabled
ID Locations (0x200 : 0x203) Read enabled, Write Enabled Read enabled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read enabled, Write Enabled Read enabled, Write Enabled
[0x00:0x3F] Read enabled, Write Enabled Read enabled, Write Enabled
[0x40:0x3FF] Read disabled (all 0’s), Write Disabled Read enabled, Write Enabled
ID Locations (0x400 : 0x403) Read enabled, Write Enabled Read enabled, Write Enabled
PIC12C5XX
DS30557E-page 3-10 2000 Microchip Technology Inc.
PIC12C509A
To code protect:
•(CP enable pattern: XXXXXXXX0XXX))
PIC12CE518
To code protect:
•(CP enable pattern: XXXXXXXX0XXX)
PIC12CE519
To code protect:
•(CP enable pattern: XXXXXXXX0XXX))
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read enabled, Write Enabled Read enabled, Write Enabled
[0x00:0x3F] Read enabled, Write Enabled Read enabled, Write Enabled
[0x40:0x3FE] Read disabled (all 0’s), Write Disabled Read enabled, Write Enabled
0x3FF Oscillator Calibration Value Read enabled, Write Enabled Read enabled, Write Enabled
ID Locations (0x400 : 0x403) Read enabled, Write Enabled Read enabled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read enabled, Write Enabled Read enabled, Write Enabled
[0x00:0x3F] Read enabled, Write Enabled Read enabled, Write Enabled
[0x40:0x1FE] Read disabled (all 0’s), Write Disabled Read enabled, Write Enabled
0x1FF Oscillator Calibration Value Read enabled, Write Enabled Read enabled, Write Enabled
ID Locations (0x200 : 0x203) Read enabled, Write Enabled Read enabled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0xFFF) Read enabled, Write Enabled Read enabled, Write Enabled
[0x00:0x3F] Read enabled, Write Enabled Read enabled, Write Enabled
[0x40:0x3FF] Read disabled (all 0’s), Write Disabled Read enabled, Write Enabled
ID Locations (0x400 : 0x403) Read enabled, Write Enabled Read enabled, Write Enabled
2000 Microchip Technology Inc. DS30557E-page 3-11
PIC12C5XX
4.2 Checksum
4.2.1 CHECKSUM CALCULATIONS
Checksum is calculated by reading the contents of the
PIC12C5XX memory locations and adding up the
opcodes up to the maximum user addressable location,
(not including the last location which is reserved for the
oscillator calibration value) e.g., 0x1FE for the
PIC12C508/CE518. Any carry bits exceeding 16-bits
are neglected. Finally, the configuration word (appropri-
ately masked) is added to the checksum. Checksum
computation for each member of the PIC12C5XX fam-
ily is shown in Table 4-2.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
The oscillator calibration value location is not used in
the above checksums.
TABLE 4-2: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank
Value
0x723 at
0 and max
address
PIC12C508 OFF
ON
SUM[0x000:0x1FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EE20
EDF7
DC68
D363
PIC12C508A OFF
ON
SUM[0x000:0x1FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EE20
EDF7
DC68
D363
PIC12C509 OFF
ON
SUM[0x000:0x3FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EC20
EBF7
DA68
D163
PIC12C509A OFF
ON
SUM[0x000:0x3FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EC20
EBF7
DA68
D163
PIC12CE518 OFF
ON
SUM[0x000:0x1FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EE20
EDF7
DC68
D363
PIC12CE519 OFF
ON
SUM[0x000:0x3FE] + CFGW & 0x01F
SUM[0x000:0x03F] + CFGW & 0x01F + SUM(IDS)
EC20
EBF7
DA68
D163
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
PIC12C5XX
DS30557E-page 3-12 2000 Microchip Technology Inc.
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
TABLE 5-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (20°C recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions
General
PD1 VDDP Supply voltage during programming 4.75 5.0 5.25 V
PD2 IDDP Supply current (from VDD)
during programming
20 mA
PD3 VDDV Supply voltage during verify VDDmin VDDmax V Note 1
PD4 VIHH1 Voltage on MCLR/VPP during
programming
12.75 13.25 V Note 2
PD5 VIHH2 Voltage on MCLR/VPP during verify VDD + 4.0 13.5
PD6 IPP Programming supply current (from
VPP)
50 mA
PD9 VIH1 (GP1, GP0) input high level 0.8 VDD V Schmitt Trigger input
PD8 VIL1 (GP1, GP0) input low level 0.2 VDD V Schmitt Trigger input
Serial Program Verify
P1 TRMCLR/VPP rise time (VSS to VHH) 8.0 µs
P2 Tf MCLR Fall time 8.0 µs
P3 Tset1 Data in setup time before clock ↓ 100 ns
P4 Thld1 Data in hold time after clock ↓ 100 ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 µs
P7 Tdly3 Clock ↑ to date out valid
(during read data)
200 ns
P8 Thld0 Hold time after MCLR ↑2µs
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
2000 Microchip Technology Inc. DS30557E-page 3-13
PIC12C5XX
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
}
}
100ns
min.
P4
P3
0
0
0
1ms min.
P5
1ms min.
P6
0
15
5432
1
6
5
Program/Verify Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
GP1
(CLOCK)
GP0
(DATA) 0
MCLR/VPP
}
00
1ms min.
P5
1ms min.
P6
15
5432
1
6
5
Program/Verify Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
GP1
(CLOCK)
GP0
(DATA) 0
MCLR/VPP
GP0 = output GP0
input
P7
}
}
}
0
000
00
11
12345 61
2
100ns
min
P3 P4
P6
1ms min. Next Command
P5
1ms min.
VIHH
MCLR/VPP
GP1
(CLOCK)
(DATA)
GP0
Reset
Program/Verify Mode
PIC12C5XX
DS30557E-page 3-14 2000 Microchip Technology Inc.
2000 Microchip Technology Inc. DS40175B-page 3-15
PIC12C67X AND PIC12CE67X
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC12C67X AND PIC12CE67X
The PIC12C67X and PIC12CE67X can be pro-
grammed using a serial method. In serial mode the
PIC12C67X and PIC12CE67X can be programmed
while in the users system. This allows for increased
design flexibility.
1.1 Hardware Requirements
The PIC12C67X and PIC12CE67X requires two pro-
grammable power supplies, one for VDD (2.0V to 6.0V
recommended) and one for VPP (12V to 14V). Both
supplies should have a minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC12C67X and
PIC12CE67X allows programming of user program
memory, special locations used for ID, and the configu-
ration word for the PIC12C67X and PIC12CE67X.
Pin Diagram:
• PIC12C671
• PIC12C672
•PIC12CE673
•PIC12CE674
PDIP, SOIC, JW
8
7
6
5
1
2
3
4
PIC12C67X
GP5/OSC1/CLKIN
GP4/OSC2/AN3/
GP3/MCLR/VPP
VDD VSS
GP0/AN0
GP1/AN1/VREF
GP2/T0CKI/
AN2/INT
CLKOUT
PDIP, JW
8
7
6
5
1
2
3
4
GP5/OSC1/CLKIN
GP4/OSC2/AN3/
GP3/MCLR/VPP
VDD VSS
GP0/AN0
GP1/AN1/VREF
GP2/T0CKI/
AN2/INT
CLKOUT
PIC12CE67X
In-Circuit Serial Programming for PIC12C67X and PIC12CE67X OTP MCUs
PIC12C67X and PIC12CE67X
DS40175B-page 3-16 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). Table 2-1 shows actual implementation
of program memory in the PIC12C67X family.
When the PC reaches the last location of the imple-
mented program memory, it will wrap around and
address a location within the physically implemented
memory (see Figure 2-1).
In programming mode the program memory space
extends from 0x0000 to 0x3FFF, with the first half
(0x0000-0x1FFF) being user program memory and the
second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x1FFF
and wrap to 0x000 or 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ’1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode, as described in
Section 2.2.
The last location of the program memory space holds
the factory programmed oscillator calibration value.
This location should not be programmed except when
blank (a non-blank value should not cause the device to
fail a blank check). If blank, the programmer should pro-
gram it to a RETLW XX statement where “XX” is the
calibration value.
In the configuration memory space, 0x2000-0x20FF
are utilized. When in configuration memory, as in the
user memory, the 0x2000-0x2XFF segment is repeat-
edly accessed as the PC exceeds 0x2XFF (see
Figure 2-1).
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000:
0x2003].
Note 1: All other locations in PICmicro® MCU con-
figuration memory are reserved and should
not be programmed.
2: Due to the secure nature of the on-board
EEPROM memory in the PIC12CE673/674,
it can be accessed only by the user pro-
gram.
TABLE 2-1: IMPLEMENTATION OF
PROGRAM MEMORY IN THE
PIC12C67X
Device Program Memory Size
PIC12C671/
PIC12CE673
0x000 - 0x3FF (1K)
PIC12C672/
PIC12CE674
0x000 - 0x7FF (2K)
2000 Microchip Technology Inc. DS40175B-page 3-17
PIC12C67X and PIC12CE67X
FIGURE 2-1: PROGRAM MEMORY MAPPING
0
3FF
400
7FF
800
BFF
C00
FFF
1000
1FFF
2000
2008
2100
3FFF
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000
2001
2002
2003
2004
2005
2006
2007
1FF
1KW 2KW
Implemented Implemented
Implemented
Reserved
Reserved
Reserved Reserved
Reserved Reserved
PIC12C67X and PIC12CE67X
DS40175B-page 3-18 2000 Microchip Technology Inc.
2.2 Program/Verify Mode
The program/verify mode is entered by holding pins
GP1 and GP0 low while raising MCLR pin from VIL to
VIHH (high voltage). VDD is then raised from VIL to
VIH.Once in this mode the user program memory and
the configuration memory can be accessed and pro-
grammed in serial fashion. The mode of operation is
serial, and the memory that is accessed is the user pro-
gram memory. GP1 is a Schmitt Trigger input in this
mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
2.2.1 PROGRAM/VERIFY OPERATION
The GP1 pin is used as a clock input pin, and the GP0
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (GP1) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin GP0 is required to have a minimum
setup and hold time (see AC/DC specs) with respect to
the falling edge of the clock. Commands that have data
associated with them (read and load) are specified to
have a minimum delay of 1µs between the command
and the data. After this delay the clock pin is cycled 16
times with the first cycle being a start bit and the last
cycle being a stop bit. Data is also input and output LSB
first. Therefore, during a read operation the LSB will be
transmitted onto pin GP0 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of the
clock. To allow for decoding of commands and reversal
of data pin configuration, a time separation of at least
1µs is required between a command and a data word
(or another command).
The commands that are available are listed in Table .
2.2.1.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits a “data word”
as described above, to be programmed into the config-
uration memory. A description of the memory mapping
schemes for normal operation and configuration mode
operation is shown in Figure 2-1. After the configura-
tion memory is entered, the only way to get back to the
user program memory is to exit the program/verify test
mode by taking MCLR low (VIL).
Note 1:The MCLR pin must be raised from VIL
to VIHH before VDD is applied. This is to
ensure that the device does not have the
PC incremented while in valid operation
range.
Note 2:Do not power GP2, GP4 or GP5
before VDD is applied.
TABLE 1-1: COMMAND MAPPING
Command Mapping (MSB ... LSB) Data
Load Configuration 000000 0, data(14), 0
Load Data 000010 0, data(14), 0
Read Data 000100 0, data(14), 0
Increment Address 000110
Begin programming 001000
End Programming 001110
2000 Microchip Technology Inc. DS40175B-page 3-19
PIC12C67X and PIC12CE67X
FIGURE 2-2: PROGRAM FLOW CHART - PIC12C67X AND PIC12CE67X PROGRAM MEMORY
Start
Set VDD = VDDP•
N = N + 1
Load Data
Command
Increment Address
Command
Report Verify
@ VDD MAX Error
End Programming
Command
Begin Programming
Command
Apply 3N Additional
Program Cycles
Read Data
Command
Program Cycle
Program Cycle N > 25
Data Correct?
Done
No
Ye s
Ye s
No
No
Ye s
Set VPP = VIHH1
N = 0
All Locations Done?
Verify all Locations
@ VDD MIN.•
VPP = VIHH2
Data Correct?
Ye s
Verify all Locations
@ VDD MAX.
VPP = VIHH2
Data Correct?
Ye s
Report Programming
Failure
Wait 100 µs
Report Verify
@ VDD MIN. Error
No
No
• VDDP = VDD range for programming (typically 4.75V - 5.25V).
VDD MIN. = Minimum VDD for device operation.
VDD MAX. = Maximum VDD for device operation.
N = # of Program Cycles
PIC12C67X and PIC12CE67X
DS40175B-page 3-20 2000 Microchip Technology Inc.
FIGURE 2-3: PROGRAM FLOW CHART - PIC12C67X AND PIC12CE67X CONFIGURATION WORD
& ID LOCATIONS
VDDmin
VDDmax
Start
Load Configuration
Command
Increment Address
Command N = N + 1
N = # of Program
ID/Configuration
Error
Increment Address
Command
Increment Address
Command
Increment Address
Command
Program Cycle
100 Cycles
Read Data
Command
Apply 3N
Program Cycles
Read Data
Command
Report Program
ID/Config. Error
Set VDD = VDDmax
Program Cycle
N = 0
Data Correct?
Data Correct?
Data Correct?
Data Correct?
N > 25
Address = 2004
Program ID Loc?
Done
Ye s
No
No
Ye s
No
Ye s
Ye s
Ye s
No
Ye s
No
No
No Yes
Read Data Command
Set VPP = VIHH2
Set VDD = VDDmin
Read Data Command
Set VPP = VIHH2
Cycles
Set VPP = VIHH1
2000 Microchip Technology Inc. DS40175B-page 3-21
PIC12C67X and PIC12CE67X
2.2.1.2 LOAD DATA
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
2.2.1.3 READ DATA
After receiving this command, the chip will transmit
data bits out of the memory currently accessed starting
with the second rising edge of the clock input. The GP0
pin will go into output mode on the second rising clock
edge, and it will revert back to input mode (hi-imped-
ance) after the 16th rising edge. A timing diagram of
this command is shown in Figure 5-2.
2.2.1.4 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.2.1.5 BEGIN PROGRAMMING
A load command (load configuration or load data)
must be given before every begin programming
command. Programming of the appropriate memory
(test program memory or user program memory) will
begin after this command is received and decoded.
Programming should be performed with a series of
100µs programming pulses. A programming pulse is
defined as the time between the begin programming
command and the end programming command.
2.2.1.6 END PROGRAMMING
After receiving this command, the chip stops program-
ming the memory (configuration program memory or
user program memory) that it was programming at the
time.
2.3 Programming Algorithm Requires
Variable VDD
The PIC12C67X and PIC12CE67X uses an intelligent
algorithm. The algorithm calls for program verification
at VDDmin as well as VDDmax. Verification at VDDmin
guarantees good “erase margin”. Verification at
VDDmax guarantees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (4.75 - 5.25V).
VDDP =VCC range required during programming.
VDD min. = minimum operating VDD spec for the part.
VDD max.= maximum operating VDD spec for the part.
Programmers must verify the PIC12C67X and
PIC12CE67X at its specified VDDmax and VDDmin lev-
els. Since Microchip may introduce future versions of
the PIC12C67X and PIC12CE67X with a broader VDD
range, it is best that these levels are user selectable
(defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
PIC12C67X and PIC12CE67X
DS40175B-page 3-22 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC12C67X and PIC12CE67X family members
have several configuration bits. These bits can be pro-
grammed (reads ’0’) or left unprogrammed (reads ’1’) to
select various device configurations. Figure 3-1 pro-
vides an overview of configuration bits.
FIGURE 3-1: CONFIGURATION WORD
Bit Number:
11 10 9 8 7654 32
FOSC2
1
FOSC1
0
FOSC0
WDTE
bit 13-8, 6-5: CP1:CP0: Code Protection bits (1) (2)
11 = Code protection off
10 = 0400h-07FFh code protected;
01 = 0200h-07FFh code protected;
00 = 0000h-07FFh code protected;
bit 7: MCLRE: GP3/MCLR pin function select
1 = GP3/MCLR pin function is MCLR
0 = GP3/MCLR pin function is digital I/O, MCLR internally tied to Vdd
bit 4: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 3: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 2-0: FOSC2:FOSC0: Oscillator Selection bits
111 = EXTRC oscillator / CLKOUT function on GP4/OSC2/CLKOUT pin
110 = EXTRC oscillator / GP4 function on GP4/OSC2/CLKOUT pin
101 = INTRC oscillator / CLKOUT function on GP4/OSC2/CLKOUT pin
100 = INTRC oscillator / GP4 function on GP4/OSC2/CLKOUT pin
011 = invalid selection
010 = HS oscillator
001 = XT oscillator
000 = LP oscillator
3: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
4: 07FFh is always uncode protected on the 12C672 and 03FFh is always uncode protected on the 12C671. This location
contains the RETLW xx calibration instruction for the INTRC.
13 12
CP0
MCLRE CP1
CP0CP1 CP0CP1 CP0CP1 PWRTE Register: CONFIG
Address 2007h
2000 Microchip Technology Inc. DS40175B-page 3-23
PIC12C67X and PIC12CE67X
4.0 CODE PROTECTION
The program code written into the EPROM can be pro-
tected by writing to the CP0 & CP1 bits of the configu-
ration word.
For PIC12C67X and PIC12CE67X devices, once code
protection is enabled, all protected segments read ’0’s
(or “garbage values”) and are prevented from further
programming. All unprotected segments, including ID
and configuration word locations, and calibration word
location read normally and can be programmed.
4.1 Embedding Configuration Word and ID Information in the Hex File
TABLE 1-2: CONFIGURATION WORD
PIC12C671, PIC12CE673
To code protect:
•Protect all memory 00 0000 X00X XXXX
•Protect 0200h-07FFh 01 0101 X01X XXXX
•No code protection 11 1111 X11X XXXX
PIC12C672, PIC12CE674
To code protect:
•Protect all memory 00 0000 X00X XXXX
•Protect 0200h-07FFh 01 0101 X01X XXXX
•Protect 0400h-07FFh 10 1010 X10X XXXX
•No code protection 11 1111 X11X XXXX
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Unprotected memory segment Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
INTRC Calibration Word (0X3FF) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Unprotected memory segment Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
INTRC Calibration Word (0X7FF) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
PIC12C67X and PIC12CE67X
DS40175B-page 3-24 2000 Microchip Technology Inc.
4.2 Checksum
4.2.1 CHECKSUM CALCULATIONS
Checksum is calculated by reading the contents of the
PIC12C67X and PIC12CE67X memory locations and
adding the opcodes up to the maximum user address-
able location, excluding the oscillator calibration loca-
tion in the last address, e.g., 0x3FE for the PIC12C671/
CE673. Any carry bits exceeding 16-bits are neglected.
Finally, the configuration word (appropriately masked)
is added to the checksum. Checksum computation for
each member of the PIC12C67X and PIC12CE67X
devices is shown in Table 4-1.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 4-1: CHECKSUM COMPUTATION
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
Device Code
Protect Checksum* Blank
Value
Ox25E6 at
0 and max
address
PIC12C671
PIC12CE673
OFF
1/2
ALL
SUM[0x000:0x3FE] + CFGW & 0x3FFF
SUM[0x000:0x1FF] + CFGW & 0x3FFF + SUM_ID
CFGW & 0x3FFF + SUM_ID
3B3F
4E5E
3B4E
070D
0013
071C
PIC12C672
PIC12CE674
OFF
1/2
3/4
ALL
SUM[0x000:0x7FE] + CFGW & 0x3FFF
SUM[0x000:0x3FF] + CFGW & 0x3FFF + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3FFF + SUM_ID
CFGW & 0x3FFF + SUM_ID
373F
5D6E
4A5E
374E
030D
0F23
FC13
031C
2000 Microchip Technology Inc. DS40175B-page 3-25
PIC12C67X and PIC12CE67X
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
TABLE 1-3: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (25°C is recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions
General
PD1 VDDP Supply voltage during programming 4.75 5.0 5.25 V
PD2 IDDP Supply current (from VDD)
during programming
20 mA
PD3 VDDV Supply voltage during verify VDDmin VDDmax V Note 1
PD4 VIHH1 Voltage on MCLR/VPP during
programming
12.75 13.25 V Note 2
PD5 VIHH2 Voltage on MCLR/VPP during verify VDD + 4.0 13.5
PD6 IPP Programming supply current (from
VPP)
50 mA
PD9 VIH1 (GP0, GP1) input high level 0.8 VDD V Schmitt Trigger input
PD8 VIL1 (GP0, GP1) input low level 0.2 VDD V Schmitt Trigger input
Serial Program Verify
P1 TRMCLR/VPP rise time (VSS to VIHH)
for test mode entry
8.0 µs
P2 Tf MCLR Fall time 8.0 µs
P3 Tset1 Data in setup time before clock ↓ 100 ns
P4 Thld1 Data in hold time after clock ↓ 100 ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 µs
P7 Tdly3 Clock ↑ to data out valid
(during read data)
200 ns
P8 Thld0 Hold time after VDD↑2µs
P9 TPPDP Hold time after VPP↑5µs
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
PIC12C67X and PIC12CE67X
DS40175B-page 3-26 2000 Microchip Technology Inc.
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
}
}
100ns
min.
P4
P3
0
0
0
1µs min.
P5
1µs min.
P6
0
155432165
Program/Verify Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
GP1
(CLOCK)
GP0
(DATA) 0
MCLR/VPP
VDD
P9
}
00
1µs min.
P5
1µs min.
P6
155432165
Program/Verify Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
GP1
(CLOCK)
GP0
(DATA) 0
MCLR/VPP
RB7 = output RB7
input
P7
}
VDD
P9
}
}
0
000
00
11
123456 12
100ns
min
P3 P4
P6
1µs min. Next Command
P5
1µs min.
VIHH
MCLR/VPP
GP1
(CLOCK)
(DATA)
GP0
Reset
Program/Verify Mode
VDD P9
2000 Microchip Technology Inc. DS30555B-page 3-27
PIC14000
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE PIC14000
The PIC14000 can be programmed using a serial
method. In serial mode the PIC14000 can be pro-
grammed while in the users system. This allows for
increased design flexibility. This programming specifi-
cation applies to PIC14000 devices in all packages.
1.1 Hardware Requirements
The PIC14000 requires two programmable power sup-
plies, one for VDD (2.0V to 6.5V recommended) and
one for VPP (12V to 14V).
1.2 Programming Mode
The programming mode for the PIC14000 allows pro-
gramming of user program memory, configuration
word, and calibration memory.
PIN DIAGRAM
• PIC14000 PDIP, SOIC, SSOP, Windowed CERDIP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RA2/AN2
RA3/AN3
RD4/AN4
RD5/AN5
RD6/AN6
RD7/AN7
CDAC
SUM
VSS
RC0/REFA
RC1/CMPA
RC2
RC3/T0CKI
RC4
PIC14000
• 1
2
3
4
5
6
7
8
9
10
11
12
13
14
RA1/AN1
RA0/AN0
RD3/REFB
RD2/CMPB
RD1/SDAB
RD0/SCLB
OSC2/CLKOUT
OSC1/PBTN
VDD
VREG
RC7/SDAA
RC6/SCLA
RC5
MCLR/VPP
In-Circuit Serial Programming for PIC14000 OTP MCUs
PIC14000
DS30555B-page 3-28 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The program and calibration memory space extends
from 0x000 to 0xFFF (4096 words). Table 2-1 shows
actual implementation of program memory in the
PIC14000.
TABLE 2-1: IMPLEMENTATION OF
PROGRAM AND
CALIBRATION MEMORY IN
THE PIC14000P
When the PC reaches address 0xFFF, it will wrap
around and address a location within the physically
implemented memory (see Figure 2-1).
In programming mode the program memory space
extends from 0x0000 to 0x3FFF, with the first half
(0x0000-0x1FFF) being user program memory and the
second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x1FFF
and wrap to 0x0000, or 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ’1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode, as described in
Section 2.2.
In the configuration memory space, 0x2000-0x20FF
are utilized. When in configuration memory, as in the
user memory, the 0x2000-0x2XFF segment is repeat-
edly accessed as PC exceeds 0x2XFF (Figure 2-1).
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000:
0x2003]. All other locations are reserved and should
not be programmed.
The ID locations read out normally, even after code pro-
tection. To understand how the devices behave, refer to
Tabl e 4- 1 .
To understand the scrambling mechanism after code
protection, refer to Section 4.1.
Area Memory Space Access to
Memory
Program 0x000-0xFBF PC<12:0>
Calibration 0xFC0 -0xFFF PC<12:0>
2000 Microchip Technology Inc. DS30555B-page 3-29
PIC14000
FIGURE 2-1: PROGRAM MEMORY MAPPING
0
0FC0
0FFF
1FFF
20FF
3FFF
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000
2001
2002
2003
2004
2005
2006
2007
0FBF
2000
Program
Reserved
Calibration
Test
Reserved
PIC14000
DS30555B-page 3-30 2000 Microchip Technology Inc.
2.2 Program/Verify Mode
The program/verify mode is entered by holding pins
RC6 and RC7 low while raising MCLR pin from VIL to
VIHH (high voltage). Once in this mode the user pro-
gram memory and the configuration memory can be
accessed and programmed in serial fashion. The mode
of operation is serial, and the memory that is accessed
is the user program memory. RC6 and RC7 are both
Schmitt Trigger inputs in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
2.2.1 PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RC6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin RC7 is required to have a minimum
setup and hold time (see AC/DC specs) with respect to
the falling edge of the clock. Commands that have data
associated with them (read and load) are specified to
have a minimum delay of 1µs between the command
and the data. After this delay the clock pin is cycled 16
times with the first cycle being a start bit and the last
cycle being a stop bit. Data is also input and output LSB
first. Therefore, during a read operation the LSB will be
transmitted onto pin RC7 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of the
clock. To allow for decoding of commands and reversal
of data pin configuration, a time separation of at least
1µs is required between a command and a data word
(or another command).
The commands that are available are listed in Table .
2.2.1.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits a “data word”
as described above, to be programmed into the config-
uration memory. A description of the memory mapping
schemes for normal operation and configuration mode
operation is shown in Figure 2-1. After the configura-
tion memory is entered, the only way to get back to the
user program memory is to exit the program/verify test
mode by taking MCLR low (VIL).
Note: The MCLR pin should be raised as quickly
as possible from VIL to VIHH. This is to
ensure that the device does not have the
PC incremented while in valid operation
range.
TABLE 2-1: COMMAND MAPPING
Command Mapping (MSB ... LSB) Data
Load Configuration 0 0 0 0 0 0 0, data(14), 0
Load Data 0000100, data(14), 0
Read Data 0001000, data(14), 0
Increment Address 0 0 0 1 1 0
Begin programming 0 0 1 0 0 0
End Programming 001110
Note: The CPU clock must be disabled during in-circuit programming (to avoid incrementing the PC).
2000 Microchip Technology Inc. DS30555B-page 3-31
PIC14000
FIGURE 2-2: PROGRAM FLOW CHART - PIC14000 PROGRAM MEMORY AND CALIBRATION
* VDDP = VDD range for programming (typically 4.75V - 5.25V).
VDDmin = Minimum VDD for device operation.
VDDmax = Maximum VDD for device operation.
Start
No
Yes
Yes
Yes
Done
No
No
No
Data Correct?
Program Cycle
Read Data
Command N = N + 1 N = #
of Program Cycles
N > 25 Report Programming
Failure
Increment Address
Command
Apply 3N Additional
Program Cycles
All Locations Done?
Data Correct? Report Verify
@ VDD min. Error
Program Cycle
Load Data
Command
Begin Programming
Command
Wait 100 µs
End Programming
Command
No
Yes
Data Correct? Report Verify
@ VDD max. Error
N = 0
Yes
Set VDD = VDDP*
Verify all Locations
@ VDD min.*
VPP = VIHH2
Verify all Locations
@ VDD max.
VPP = VIHH2
PIC14000
DS30555B-page 3-32 2000 Microchip Technology Inc.
FIGURE 2-3: PROGRAM FLOW CHART - PIC14000 CONFIGURATION WORD & ID LOCATIONS
VDDmin
VDDmax
Start
Load Configuration
Command
Increment Address
Command N = N + 1 N = #
of Program Cycles
Report ID
Configuration Error
Increment Address
Command
Increment Address
Command
Increment Address
Command
Program Cycle
100 Cycles
Read Data
Command
Apply 3N
Program Cycles
Read Data
Command
Report Program
ID/Config. Error
Set VDD = VDDmax
Program Cycle
N = 0
Data Correct?
Data Correct?
Data Correct?
Data Correct?
N > 25
Address = 2004
Program ID Loc?
Done
Ye s
No
No
Ye s
No
Ye s
Ye s
Ye s
No
Ye s
No
No
No Yes
Read Data Command
Set VPP = VIHH2
Set VDD = VDDmin
Read Data Command
Set VPP = VIHH2
2000 Microchip Technology Inc. DS30555B-page 3-33
PIC14000
2.2.1.2 LOAD DATA
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
2.2.1.3 READ DATA
After receiving this command, the chip will transmit
data bits out of the memory currently accessed starting
with the second rising edge of the clock input. The RC7
pin will go into output mode on the second rising clock
edge, and it will revert back to input mode (hi-imped-
ance) after the 16th rising edge. A timing diagram of
this command is shown in Figure 5-2.
2.2.1.4 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.2.1.5 BEGIN PROGRAMMING
A load command (load configuration or load data)
must be given before every begin programming
command. Programming of the appropriate memory
(test program memory or user program memory) will
begin after this command is received and decoded.
Programming should be performed with a series of
100µs programming pulses. A programming pulse is
defined as the time between the begin programming
command and the end programming command.
2.2.1.6 END PROGRAMMING
After receiving this command, the chip stops program-
ming the memory (configuration program memory or
user program memory) that it was programming at the
time.
2.3 Programming Algorithm Requires
Variable VDD
The PIC14000 uses an intelligent algorithm. The algo-
rithm calls for program verification at VDDmin as well as
VDDmax. Verification at VDDmin guarantees good
“erase margin”. Verification at VDDmax guarantees
good “program margin”.
The actual programming must be done with VDD in the
VDDP range (4.75 - 5.25V).
VDDP =VCC range required during programming.
VDDmin = minimum operating VDD spec for the part.
VDDmax = maximum operating VDD spec for the part.
Programmers must verify the PIC14000 at its specified
VDDmax and VDDmin levels. Since Microchip may
introduce future versions of the PIC14000 with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
PIC14000
DS30555B-page 3-34 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC14000 has several configuration bits. These
bits can be programmed (reads ’0’) or left unpro-
grammed (reads ’1’) to select various device configura-
tions. Figure 3-1 provides an overview of configuration
bits.
FIGURE 3-1: CONFIGURATION WORD BIT MAP
Bit
Number: 13 12 11 10 9 8 7 654 3 2 1 0
PIC14000 CPC CPP1 CPP0 CPP0 CPP1 CPC CPC F CPP1 CPP0 PWRTE WDTE F FOSC
CPP<1:0>
11: All Unprotected
10: N/A
01: N/A
00: All Protected
bit 1,6: F Internal trim, factory programmed. DO NOT CHANGE! Program as ‘1’. Note 1.
bit 3: PWRTE, Power Up Timer Enable Bit
0 = Power up timer enabled
1 = Power up timer disabled (unprogrammed)
bit 2: WDTE, WDT Enable Bit
0 = WDT disabled
1 = WDT enabled (unprogrammed)
bit 0: FOSC<1:0>, Oscillator Selection Bit
0: HS oscillator (crystal/resonator)
1: Internal RC oscillator (unprogrammed)
Note 1: See Section 4.1.2 for cautions.
2000 Microchip Technology Inc. DS30555B-page 3-35
PIC14000
4.0 CODE PROTECTION
The memory space in the PIC14000 is divided into two
areas: program space (0-0xFBF) and calibration space
(0xFC0-0xFFF).
For program space or user space, once code protection
is enabled, all protected segments read ‘0’s (or “gar-
bage values”) and are prevented from further program-
ming. All unprotected segments, including ID locations
and configuration word, read normally. These locations
can be programmed.
4.1 Calibration Space
The calibration space can contain factory-generated
and programmed values. For non-JW devices, the CPC
bits in the configuration word are set to ‘0’ at the factory,
and the calibration data values are write-protected;
they may still be read out, but not programmed. JW
devices contain the factory values, but DO NOT have
the CPC bits set.
Microchip does not recommend setting code protect
bits in windowed devices to ‘0’. Once code-protected,
the device cannot be reprogrammed.
4.1.1 CALIBRATION SPACE CHECKSUM
The data in the calibration space has its own check-
sum. When properly programmed, the calibration
memory will always checksum to 0x0000. When this
checksum is 0x0000, and the checksum of memory
[0x0000:0xFBF] is 0x2FBF, the part is effectively blank,
and the programmer should indicate such.
If the CPC bits are set to ‘1’, but the checksum of the
calibration memory is 0x0000, the programmer should
NOT program locations in the calibration memory
space, even if requested to do so by the operator. This
would be the case for a new JW device.
If the CPC bits are set to ‘1’, and the checksum of the
calibration memory is NOT 0x0000, the programmer is
allowed to program the calibration space as directed by
the operator.
The calibration space contains specially coded data
values used for device parameter calibration. The pro-
grammer may wish to read these values and display
them for the operator’s convenience. For further infor-
mation on these values and their coding, refer to
AN621 (DS00621B).
4.1.2 REPROGRAMMING CALIBRATION SPACE
The operator should be allowed to read and store the
data in the calibration space, for future reprogramming
of the device. This procedure is necessary for repro-
gramming a windowed device, since the calibration
data will be erased along with the rest of the memory.
When saving this data, Configuration Word <1,6> must
also be saved, and restored when the calibration data
is reloaded.
4.2 Embedding Configuration Word and ID Information in the Hex File
TABLE 4-1: CODE PROTECT OPTIONS
•Protect calibration memory
0XXXX00XXXXXXX
•Protect program memory
X0000XXX00XXXX
•No code protection
1111111X11XXXX
Legend: X = Don’t care
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Unprotected memory segment Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
Protected calibration memory Read Unscrambled, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
PIC14000
DS30555B-page 3-36 2000 Microchip Technology Inc.
4.3 Checksum
4.3.1 CHECKSUM CALCULATIONS
Checksum is calculated by reading the contents of the
PIC14000 memory locations and adding up the
opcodes up to the maximum user addressable location,
0xFBF. Any carry bits exceeding 16-bits are neglected.
Finally, the configuration word (appropriately masked)
is added to the checksum. Checksum computation for
the PIC14000 device is shown in Table 4-2:
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 4-2: CHECKSUM COMPUTATION
Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
OFF
OFF OTP
ON
SUM[0000:0FBF] + CFGW & 0x3FBD
SUM[0000:0FBF] + CFGW & 0x3FBD
CFGW & 0x3FBD + SUM(IDs)
0x2FFD
0x0E7D
0x300A
0xFBCB
0xDA4B
0xFBD8
Legend: CFGW = Configuration Word
SUM[A:B] = [Sum of locations a through b inclusive]
SUM(ID) = ID locations masked by 0x7F then made into a 28-bit value with ID0 as the most significant byte
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
2000 Microchip Technology Inc. DS30555B-page 3-37
PIC14000
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
TABLE 5-1: AC/DC CHARACTERISTICS
AC/DC TIMING REQUIREMENTS FOR PROGRAM/VERIFY MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (25°C recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions
General
PD1 VDDP Supply voltage during programming 4.75 5.0 5.25 V
PD2 IDDP Supply current (from VDD)
during programming
––20 mA
PD3 VDDV Supply voltage during verify VDDmin VDDmax V Note 1
PD4 VIHH1 Voltage on MCLR/VPP during
programming
12.75 –13.25 V Note 2
PD5 VIHH2 Voltage on MCLR/VPP during verify VDD + 4.0 13.5
PD6 IPP Programming supply current (from
VPP)
––50 mA
PD9 VIH1 (RC6, RC7) input high level 0.8 VDD –– V Schmitt Trigger input
PD8 VIL1 (RC6, RC7) input low level 0.2 VDD –– V Schmitt Trigger input
Serial Program Verify
P1 TRMCLR/VPP rise time (VSS to VHH)
for test mode entry
––8.0 µs
P2 Tf MCLR Fall time ––8.0 µs
P3 Tset1 Data in setup time before clock ↓ 100 ––ns
P4 Thld1 Data in hold time after clock ↓ 100 ––ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 ––µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 ––µs
P7 Tdly3 Clock ↑ to date out valid
(during read data)
200 ––ns
P8 Thld0 Hold time after MCLR ↑2––µs
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
Note 2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
PIC14000
DS30555B-page 3-38 2000 Microchip Technology Inc.
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
}
}
100ns
min.
P4
P3
0
0
0
1µs min.
P5
1µs min.
P6
0
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RC6
(CLOCK)
RC7
(DATA) 0
MCLR/VPP
}
00
1µs min.
P5
1µs min.
P6
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RC6
(CLOCK)
RC7
(DATA) 0
MCLR/VPP
RC7 = output RC7
input
P7
}
}
}
0
000
00
11
12345 61
2
100ns
min
P3 P4
P6
1µs min. Next Command
P5
1µs min.
VIHH
MCLR/VPP
RC6
(CLOCK)
(DATA)
RC7
Reset
Program/Verify Test Mode
2000 Microchip Technology Inc. DS30261C-page 3-39
PIC16C55X
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC16C55X
The PIC16C55X can be programmed using a serial
method. In serial mode the PIC16C55X can be pro-
grammed while in the users system. This allows for
increased design flexibility.
1.1 Hardware Requirements
The PIC16C55X requires two programmable power
supplies, one for VDD (2.0V to 6.5V recommended) and
one for VPP (12V to 14V). Both supplies should have a
minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC16C55X allows pro-
gramming of user program memory, special locations
used for ID, and the configuration word for the
PIC16C55X.
PIN Diagrams
• PIC16C554
• PIC16C556
• PIC16C558 RA1
RA0
OSC2/CLKOUT
VDD
RB7
RB6
RB5
RB4
OSC1/CLKIN
RA2
RA3
MCLR
VSS
RB0/INT
RB1
RB2
RB3
RA4/T0CKI
PIC16C55X
RA1
RA0
OSC2/CLKOUT
VDD
RB7
RB6
RB5
RB4
OSC1/CLKIN
RA2
RA3
MCLR
VSS
VSS
RB0/INT
RB1
RB2
RA4/T0CKI
PIC16C55X
RB3RB3
VDD
PDIP, SOIC, Windowed CERDIP
SSOP
2
3
4
5
6
7
8
9
10
•1
2
3
4
5
6
7
8
9
•1
19
18
16
15
14
13
12
11
17
18
17
15
14
13
12
11
10
16
20
In-Circuit Serial Programming for PIC16C55X OTP MCUs
30261C.fm Page 39 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page 3-40 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). Table 2-1 shows actual implementation
of program memory in the PIC16C55X family.
TABLE 2-1: IMPLEMENTATION OF
PROGRAM MEMORY IN THE
PIC16C55X
When the PC reaches the last location of the imple-
mented program memory, it will wrap around and
address a location within the physically implemented
memory (see Figure 2-1).
In programming mode the program memory space
extends from 0x0000 to 0x3FFF, with the first half
(0x0000-0x1FFF) being user program memory and the
second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x1FFF
and wrap to 0x000 or 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ’1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode, as described in
Section 2.2.
In the configuration memory space, 0x2000-0x20FF
are utilized. When in a configuration memory, as in the
user memory, the 0x2000-0x2XFF segment is repeat-
edly accessed as the PC exceeds 0x2XFF (see
Figure 2-1).
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000:
0x2003]. It is recommended that the user use only the
four least significant bits of each ID location. In some
devices, the ID locations read-out in a scrambled fash-
ion after code protection is enabled. For these devices,
it is recommended that ID location is written as “11
1111 1000 bbbb” where 'bbbb' is ID information.
Note: All other locations are reserved and should
not be programmed.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 4-1.
To understand the scrambling mechanism after code
protection, refer to Section 4.1.
Device Program Memory Size
Access to
Program
Memory
PIC16C554 0x000 - 0x1FF (0.5K) PC<8:0>
PIC16C556 0x000 - 0x3FF (1K) PC<9:0>
PIC16C558 0x000 - 0x7FF (2K) PC<10:0>
30261C.fm Page 40 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30261C-page 3-41
PIC16C55X
FIGURE 2-1: PROGRAM MEMORY MAPPING
0.5KW 1KW 2KW
Implemented Implemented
Implemented
Reserved
Reserved Reserved Reserved
Reserved Reserved Reserved
0
3FF
400
7FF
800
BFF
C00
FFF
1000
1FFF
2000
2008
2100
3FFF
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000
2001
2002
2003
2004
2005
2006
2007
1FF
Reserved
Reserved
Implemented
Reserved
Reserved
30261C.fm Page 41 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page3-42 2000 Microchip Technology Inc.
2.2 Program/Verify Mode
The program/verify mode is entered by holding pins
RB6 and RB7 low while raising MCLR pin from VIL to
VIHH (high voltage). Once in this mode the user pro-
gram memory and the configuration memory can be
accessed and programmed in serial fashion. The mode
of operation is serial, and the memory that is accessed
is the user program and configuration memory. RB6 is
a Schmitt Trigger input in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
2.2.1 PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RB6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin RB7 is required to have a minimum
setup and hold time (see AC/DC specs) with respect to
the falling edge of the clock. Commands that have data
associated with them (read and load) are specified to
have a minimum delay of 1µs between the command
and the data. After this delay the clock pin is cycled 16
times with the first cycle being a start bit and the last
cycle being a stop bit. Data is also input and output LSB
first. Therefore, during a read operation the LSB will be
transmitted onto pin RB7 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
The commands that are available are listed
in Table 2-1.
2.2.1.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits a “data word”
as described above, to be programmed into the config-
uration memory. A description of the memory mapping
schemes for normal operation and configuration mode
operation is shown in Figure 2-1. After the configura-
tion memory is entered, the only way to get back to the
user program memory is to exit the program/verify test
mode by taking MCLR low (VIL).
Note: The MCLR pin should be raised as quickly
as possible from VIL to VIHH. this is to
ensure that the device does not have the
PC incremented while in valid operation
range.
TABLE 2-1: COMMAND MAPPING
Command Mapping (MSB ... LSB) Data
Load Configuration 000000 0, data(14), 0
Load Data 000010 0, data(14), 0
Read Data 000100 0, data(14), 0
Increment Address 000110
Begin programming 001000
End Programming 001110
Note: The CPU clock must be disabled during in-circuit programming.
30261C.fm Page 42 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30261C-page 3-43
PIC16C55X
FIGURE 2-2: PROGRAM FLOW CHART - PIC16C55X PROGRAM MEMORY
* VDDP = VDD range for programming (typically 4.75V - 5.25V).
VDDmin = Minimum VDD for device operation.
VDDmax = Maximum VDD for device operation.
Start
No
Yes
Yes
Yes
Done
No
No
No
Data Correct?
Program Cycle
Read Data
Command N = N + 1 N = #
of Program Cycles
N > 25 Report Programming
Failure
Increment Address
Command
Apply 3N Additional
Program Cycles
All Locations Done?
Data Correct? Report Verify
@ V
DD
min. Error
Program Cycle
Load Data
Command
Begin Programming
Command
Wait 100 µs
End Programming
Command
No
Yes
Data Correct? Report Verify
@ V
DD
max. Error
N = 0
Yes
Set V
DD
= V
DDP
*
Verify all Locations
@ V
DD
min.*
V
PP
= V
IHH2
Verify all Locations
@ V
DD
max.
V
PP
= V
IHH2
30261C.fm Page 43 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page 3-44 2000 Microchip Technology Inc.
FIGURE 2-3: PROGRAM FLOW CHART - PIC16C55X CONFIGURATION WORD & ID LOCATIONS
VDDmin
VDDmax
Start
Load Configuration
Command
Increment Address
Command N = N + 1 N = #
of Program Cycles
ID/Configuration
Error
Increment Address
Command
Increment Address
Command
Increment Address
Command
Program Cycle
100 Cycles
Read Data
Command
Apply 3N
Program Cycles
Read Data
Command
Report Program
ID/Config. Error
Set VDD = VDDmax
Program Cycle
N = 0
Data Correct?
Data Correct?
Data Correct?
Data Correct?
N > 25
Address = 2004
Program ID Loc?
Done
Ye s
No
No
Ye s
No
Ye s
Ye s
Ye s
No
Ye s
No
No
No Yes
Read Data Command
Set VPP = VIHH2
Set VDD = VDDmin
Read Data Command
Set VPP = VIHH2
30261C.fm Page 44 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30261C-page 3-45
PIC16C55X
2.2.1.2 LOAD DATA
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
2.2.1.3 READ DATA
After receiving this command, the chip will transmit
data bits out of the memory currently accessed starting
with the second rising edge of the clock input. The RB7
pin will go into output mode on the second rising clock
edge, and it will revert back to input mode (hi-imped-
ance) after the 16th rising edge. A timing diagram of
this command is shown in Figure 5-2.
2.2.1.4 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.2.1.5 BEGIN PROGRAMMING
A load command (load configuration or load data)
must be given before every begin programming
command. Programming of the appropriate memory
(test program memory or user program memory) will
begin after this command is received and decoded.
Programming should be performed with a series of
100µs programming pulses. A programming pulse is
defined as the time between the begin programming
command and the end programming command.
2.2.1.6 END PROGRAMMING
After receiving this command, the chip stops program-
ming the memory (configuration program memory or
user program memory) that it was programming at the
time.
2.3 Programming Algorithm Requires
Variable VDD
The PIC16C55X uses an intelligent algorithm. The
algorithm calls for program verification at VDDmin as
well as VDDmax. Verification at VDDmin guarantees
good “erase margin”. Verification at VDDmax guaran-
tees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (4.75 - 5.25V).
VDDP =VCC range required during programming.
VDD min. = minimum operating VDD spec for the part.
VDD max.= maximum operating VDD spec for the part.
Programmers must verify the PIC16C55X at its speci-
fied VDDmax and VDDmin levels. Since Microchip may
introduce future versions of the PIC16C55X with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
30261C.fm Page 45 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page 3-46 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC16C55X family members have several configu-
ration bits. These bits can be programmed (reads ’0’) or
left unprogrammed (reads ’1’) to select various device
configurations. Figure 3-1 provides an overview of con-
figuration bits.
FIGURE 3-1: CONFIGURATION WORD BIT MAP
Bit
Number: 13 12 11 10 9 8 7 654 3 2 1 0
PIC16C554/556/558 CP1 CP0 CP1 CP0 CP1 CP0 —0CP1
CP0 PWRTE WDTE FOSC1 FOSC0
bit 7: Reserved for future use
bit 6: Set to 0
bit 5-4: CP1:CP0, Code Protect
bit 8-13
bit 3: PWRTE, Power Up Timer Enable Bit
PIC16C554/556/558:
0 = Power up timer enabled
1 = Power up timer disabled
bit 2: WDTE, WDT Enable Bit
1 = WDT enabled
0 = WDT disabled
bit 1-0:FOSC<1:0>, Oscillator Selection Bit
11: RC oscillator
10: HS oscillator
01: XT oscillator
00: LP oscillator
Device CP1 CP0 Code Protection
PIC16C554 All memory protected
Do not use
Do not use
Code protection off
0 0
0 1
1 0
1 1
PIC16C556 All memory protected
Upper 1/2 memory protected
Do not use
Code protection off
0 0
0 1
1 0
1 1
PIC16C558 All memory protected
Upper 3/4 memory protected
Upper 1/2 memory protected
Code protection off
0 0
0 1
1 0
1 1
30261C.fm Page 46 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30261C-page 3-47
PIC16C55X
4.0 CODE PROTECTION
The program code written into the EPROM can be pro-
tected by writing to the CP0 & CP1 bits of the configu-
ration word.
4.1 Programming Locations 0x0000 to
0x03F after Code Protection
For PIC16C55X devices, once code protection is
enabled, all protected segments read '0's (or “garbage
values”) and are prevented from further programming.
All unprotected segments, including ID locations and
configuration word, read normally. These locations can
be programmed.
4.2 Embedding Configuration Word and ID Information in the Hex File
TABLE 4-1: CONFIGURATION WORD
PIC16C554
To code protect:
•Protect all memory 0000001000XXXX
•No code protection 1111111011XXXX
PIC16C556
To code protect:
•Protect all memory 0000001000XXXX
•Protect upper 1/2 memory 0101011001XXXX
•No code protection 1111111011XXXX
PIC16C558
To code protect:
•Protect all memory 0000001000XXXX
•Protect upper 3/4 memory 0101011001XXXX
•Protect upper 1/2 memory 1010101010XXXX
•No code protection 1111111011XXXX
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Protected memory segment Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations (0x2000 : 0x2003) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
30261C.fm Page 47 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page 3-48 2000 Microchip Technology Inc.
4.3 Checksum
4.3.1 CHECKSUM CALCULATIONS
Checksum is calculated by reading the contents of the
PIC16C55X memory locations and adding up the
opcodes up to the maximum user addressable location,
e.g., 0x1FF for the PIC16C74. Any carry bits exceeding
16-bits are neglected. Finally, the configuration word
(appropriately masked) is added to the checksum.
Checksum computation for each member of the
PIC16C55X devices is shown in Table .
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 4-2: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
PIC16C554 OFF
ALL
SUM[0x000:0x1FF] + CFGW & 0x3F3F
SUM_ID + CFGW & 0x3F3F
3D3F
3D4E
090D
091C
PIC16C556 OFF
1/2
ALL
SUM[0x000:0x3FF] + CFGW & 0x3F3F
SUM[0x000:0x1FF] + CFGW & 0x3F3F + SUM_ID
CFGW & 0x3F3F + SUM_ID
3B3F
4E5E
3B4E
070D
0013
071C
PIC16C558 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F3F
SUM[0x000:0x3FF] + CFGW & 0x3F3F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F3F + SUM_ID
CFGW & 0x3F3F + SUM_ID
373F
5D6E
4A5E
374E
030D
0F23
FC13
031C
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
30261C.fm Page 48 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30261C-page 3-49
PIC16C55X
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
TABLE 5-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (25°C is recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions
General
PD1 VDDP Supply voltage during programming 4.75 5.0 5.25 V
PD2 IDDP Supply current (from VDD)
during programming
--20 mA
PD3 VDDV Supply voltage during verify VDDmin - VDDmax V Note 1
PD4 VIHH1 Voltage on MCLR/VPP during
programming
12.75 - 13.25 V Note 2
PD5 VIHH2 Voltage on MCLR/VPP during verify VDD + 4.0 - 13.5 -
PD6 IPP Programming supply current (from
VPP)
--50mA
PD9 VIH1 (RB6, RB7) input high level 0.8 VDD - - V Schmitt Trigger input
PD8 VIL1 (RB6, RB7) input low level 0.2 VDD - - V Schmitt Trigger input
Serial Program Verify
P1 T
RMCLR/VPP rise time (VSS to VHH)
for test mode entry
--8.0µs
P2 Tf MCLR Fall time - - 8.0 µs
P3 Tset1 Data in setup time before clock ↓ 100 - - ns
P4 Thld1 Data in hold time after clock ↓ 100 - - ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 - - µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 - - µs
P7 Tdly3 Clock ↑ to date out valid
(during read data)
200 - - ns
P8 Thld0 Hold time after MCLR ↑2--µs
- Tpw Programming Pulse Width 10 100 1000 µs
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
30261C.fm Page 49 Wednesday, May 3, 2000 12:18 PM
PIC16C55X
DS30261C-page 3-50 2000 Microchip Technology Inc.
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
}
}
100ns
min.
P4
P3
0
0
0
1µs min.
P5
1µs min.
P6
0
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR/VPP
}
00
1µs min.
P5
1µs min.
P6
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR/VPP
RB7 = output RB7
input
P7
}
}
}
0
000
00
11
12345 61
2
100ns
min
P3 P4
P6
1µs min. Next Command
P5
1µs min.
VIHH
MCLR/VPP
RB6
(CLOCK)
(DATA)
RB7
Reset
Program/Verify Test Mode
30261C.fm Page 50 Wednesday, May 3, 2000 12:18 PM
2000 Microchip Technology Inc. DS30228J-page 3-51
PIC16C6XX/7XX/9XX
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC16C6XX/7XX/9XX
The PIC16C6XX/7XX/9XX can be programmed using a
serial method. In serial mode the PIC16C6XX/7XX/
9XX can be programmed while in the users system.
This allows for increased design flexibility. This pro-
gramming specification applies to PIC16C6XX/7XX/
9XX devices in all packages.
1.1 Hardware Requirements
The PIC16C6XX/7XX/9XX requires two programmable
power supplies, one for VDD (2.0V to 6.5V recom-
mended) and one for VPP (12V to 14V). Both supplies
should have a minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC16C6XX/7XX/9XX
allows programming of user program memory, special
locations used for ID, and the configuration word for the
PIC16C6XX/7XX/9XX.
Pin Diagrams
• PIC16C61 • PIC16C72A • PIC16CE623
• PIC16C62 • PIC16C73 • PIC16CE624
• PIC16C62A • PIC16C73A • PIC16CE625
• PIC16C62B • PIC16C73B • PIC16C710
• PIC16C63 • PIC16C74 • PIC16C711
• PIC16C63A • PIC16C74A • PIC16C712
• PIC16C64 • PIC16C74B • PIC16C716
• PIC16C64A • PIC16C76 • PIC16C745
• PIC16C65 • PIC16C77 • PIC16C765
• PIC16C65A • PIC16C620 • PIC16C773
• PIC16C65B • PIC16C620A • PIC16C774
• PIC16C66 • PIC16C621 • PIC16C923
• PIC16C67 • PIC16C621A • PIC16C924
• PIC16C71 • PIC16C622
• PIC16C72 • PIC16C622A
PIC16C62/62A/63/66/72/72A
PIC16C73/73A/73B/76/745
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RD7
RD6
RD5
RD4
RC7
RC6
RC5
RC4
RD3
RD2
MCLR/VPP
RA0
RA1
RA2
RA3
RA4/T0CKI
RA5
RE0
RE1
RE2
VDD
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0
RC1
RC2
RC3
RD0
RD1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
PDIP, Windowed CERDIP
PDIP, SOIC, Windowed CERDIP (300 mil)
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RC7
RC6
RC5
RC4
• 1
2
3
4
5
6
7
8
9
10
11
12
13
14
MCLR/VPP
RA0
RA1
RA2
RA3
RA4/T0CKI
RA5
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0
RC1
RC2
RC3
PIC16C64/64A/65/65A/67
PIC16C74/74A/74B/77/765
In-Circuit Serial Programming for PIC16C6XX/7XX/9XX OTP MCUs
PIC16C6XX/7XX/9XX
DS30228J-page 3-52 2000 Microchip Technology Inc.
Pin Diagrams (Con’t)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
9
8
7
6
5
4
3
2
1
68
67
66
65
64
63
62
61
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
PIC16C924
RD5/SEG29/COM3
RG6/SEG26
RG5/SEG25
RG4/SEG24
RG3/SEG23
RG2/SEG22
RG1/SEG21
RG0/SEG20
RG7/SEG28
RF7/SEG19
RF6/SEG18
RF5/SEG17
RF4/SEG16
RF3/SEG15
RF2/SEG14
RF1/SEG13
RF0/SEG12
RA4/T0CKI
RA5/AN4/SS
RB1
RB0/INT
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
VLCD2
VLCD3
AVDD
VDD
VSS
C1
C2
OSC1/CLKIN
OSC2/CLKOUT
RC0/T1OSO/T1CKI
RA3/AN3/V
REF
RA2/AN2
V
SS
RA1/AN1
RA0/AN0
RB2
RB3
MCLR/V
PP
N/C
RB4
RB5
RB7
RB6
V
DD
COM0
RD7/SEG31/COM1
RD6/SEG30/COM2
RC1/T1OSI
RC2/CCP1
V
LCD
1
VLCDADJ
RD0/SEG00
RD1/SEG01
RD2/SEG02
RD3/SEG03
RD4/SEG04
RE7/SEG27
RE0/SEG05
RE1/SEG06
RE2/SEG07
RE3/SEG08
RE4/SEG09
RE6/SEG11
RE5/SEG10
PLCC
PDIP, SOIC, Windowed CERDIP
18
17
16
15
14
13
12
11
10
• 1
2
3
4
5
6
7
8
9
RA2
RA3
RA4/T0CKI
MCLR/VPP
VSS
RB0/INT
RB1
RB2
RB3
RA1
RA0
OSC1/CLKIN
OSC2/CLKOUT
VDD
RB7
RB6
RB5
RB4
PIC16C61/71
PIC16C62X
PIC16C710/711
PIC16C923
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/VRL
RA3/AN3/VREF+/VRH
RA4/T0CKI
AVDD
AVSS
OSC1/CLKIN
OSC2/CLKOUT
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RB7
RB6
RB5
RB4
RB3/AN9/LVDIN
RB2/AN8
RB1/SS
RB0/INT
VDD
VSS
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
• 1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
300 mil. SDIP, SOIC, Windowed CERDIP, SSOP
PIC16C773
PIC16C712
RA2/AN2
RA4/T0CKI
RB0/INT
RB1/T1OSO/T1CKI
RA0/AN0
OSC1/CLKIN
RB7
RB6
• 1
2
3
4
5
6
7
18
17
16
15
14
13
12
8
9
11
10
18 pin PDIP, SOIC, Windowed CERDIP
MCLR/VPP
RA3/AN3/VREF
RB2/T1OSI
RB3/CCP1 RB4
RB5
RA1/AN1
VDD
OSC2/CLKOUT
VSS
PIC16C716
PIC16C712
RA2/AN2
RA4/T0CKI
RB0/INT
RB1/T1OSO/T1CKI
RA0/AN0
OSC1/CLKIN
RB7
RB6
• 1
2
3
4
5
6
7
20
19
18
17
16
15
14
8
9
13
12
20 pin SSOP
MCLR/VPP
RA3/AN3/VREF
RB2/T1OSI
RB3/CCP1 RB4
RB5
RA1/AN1
VDD
OSC2/CLKOUT
VSS
PIC16C716
10
VSS VDD
11
2000 Microchip Technology Inc. DS30228J-page 3-53
PIC16C6XX/7XX/9XX
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). Table 2-1 shows actual implementation
of program memory in the PIC16C6XX/7XX/9XX fam-
ily.
TABLE 2-1: IMPLEMENTATION OF
PROGRAM MEMORY IN THE
PIC16C6XX/7XX/9XX
When the PC reaches the last location of the imple-
mented program memory, it will wrap around and
address a location within the physically implemented
memory (see Figure 2-1).
Once in configuration memory, the highest bit of the PC
stays a ’1’, thus always pointing to the configuration
memory. The only way to point to user program mem-
ory is to reset the part and reenter program/verify
mode, as described in Section 2.2.
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000:
0x2003]. It is recommended that the user use only the
four least significant bits of each ID location. In some
devices, the ID locations read-out in a scrambled fash-
ion after code protection is enabled. For these devices,
it is recommended that ID location is written as “11
1111 1bbb bbbb” where 'bbbb' is ID information.
Note: All other locations are reserved and should
not be programmed.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 4-1.
To understand the scrambling mechanism after code
protection, refer to Section 3.1.
Device Program Memory
Size
PIC16C61 0x000 – 0x3FF (1K)
PIC16C620/620A 0x000 – 0x1FF (0.5K)
PIC16C621/621A 0x000 – 0x3FF (1K)
PIC16C622/622A 0x000 – 0x7FF (2K)
PIC16C62/62A/62B 0x000 – 0x7FF (2K)
PIC16C63/63A 0x000 – 0xFFF (4K)
PIC16C64/64A 0x000 – 0x7FF (2K)
PIC16C65/65A/65B 0x000 – 0xFFF (4K)
PIC16CE623 0x000 – 0x1FF (0.5K)
PIC16CE624 0x000 – 0x3FF (1K)
PIC16CE625 0x000 – 0x7FF (2K)
PIC16C71 0x000 – 0x3FF (1K)
PIC16C710 0x000 – 0x1FF (0.5K)
PIC16C711 0x000 – 0x3FF (1K)
PIC16C712 0x000 – 0x3FF (1K)
PIC16C716 0x000 – 0x7FF (2K)
PIC16C72/72A 0x000 – 0x7FF (2K)
PIC16C73/73A/73B 0x000 – 0xFFF (4K)
PIC16C74/74A/74B 0x000 – 0xFFF (4K)
PIC16C66 0x000 – 0x1FFF (8K)
PIC16C67 0x000 – 0x1FFF (8K)
PIC16C76 0x000 – 0x1FFF (8K)
PIC16C77 0x000 – 0x1FFF (8K)
PIC16C745 0x000 – 0x1FFF (8K)
PIC16C765 0x000 – 0x1FFF (8K)
PIC16C773 0x000 – 0xFFF (4K)
PIC16C774 0x000 – 0xFFF (4K)
PIC16C923/924 0x000 – 0xFFF (4K)
PIC16C6XX/7XX/9XX
DS30228J-page 3-54 2000 Microchip Technology Inc.
FIGURE 2-1: PROGRAM MEMORY MAPPING
0.5K
words
1K
words
2K
words
4K
words
8K
words
Implemented Implemented Implemented Implemented Implemented
Implemented Implemented Implemented
Reserved Implemented Implemented
Reserved Implemented Implemented
Reserved Implemented
Reserved Implemented
Implemented
Implemented
Reserved Reserved Reserved Reserved Reserved
Reserved Reserved Reserved Reserved Reserved
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000h
2001h
2002h
2003h
2004h
2005h
2006h
2007h
0h
1FFh
3FFh
400h
7FFh
800h
BFFh
C00h
FFFh
1000h
1FFFh
2008h
2100h
3FFFh
2000 Microchip Technology Inc. DS30228J-page 3-55
PIC16C6XX/7XX/9XX
2.2 Program/Verify Mode
The program/verify mode is entered by holding pins
RB6 and RB7 low while raising MCLR pin from VSS to
the appropriate VIHH (high voltage). Once in this mode
the user program memory and the configuration mem-
ory can be accessed and programmed in serial fash-
ion. The mode of operation is serial, and the memory
that is accessed is the user program memory. RB6 is a
Schmitt Trigger input in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VSS). This means
that all I/O are in the reset state (High impedance
inputs).
2.2.1 PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RB6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSb) of the command being input first.
The data on pin RB7 is required to have a minimum
setup and hold time (see AC/DC specs) with respect to
the falling edge of the clock. Commands that have data
associated with them (read and load) are specified to
have a minimum delay of 1 µs between the command
and the data. After this delay the clock pin is cycled 16
times with the first cycle being a start bit and the last
cycle being a stop bit. Data is also input and output LSb
first. Therefore, during a read operation the LSb will be
transmitted onto pin RB7 on the rising edge of the sec-
ond cycle, and during a load operation the LSb will be
latched on the falling edge of the second cycle. A min-
imum 1 µs delay is also specified between consecutive
commands.
All commands are transmitted LSb first. Data words are
also transmitted LSb first. The data is transmitted on
the rising edge and latched on the falling edge of the
clock. To allow for decoding of commands and reversal
of data pin configuration, a time separation of at least
1µs is required between a command and a data word
(or another command).
The commands that are available are listed
in Table 2-2.
2.2.1.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits a “data word”
as described above, to be programmed into the config-
uration memory. A description of the memory mapping
schemes for normal operation and configuration mode
operation is shown in Figure 2-1. After the configura-
tion memory is entered, the only way to get back to the
user program memory is to exit the program/verify test
mode by taking MCLR low (VIL).
TABLE 2-2: COMMAND MAPPING
Note 1: The MCLR pin should be raised as quickly
as possible from VIL to VIHH. this is to
ensure that the device does not have the
PC incremented while in valid operation
range.
2: Do not power any pin before VDD is
applied.
Command Mapping (MSb... LSb) Data
Load Configuration 0000000, data(14), 0
Load Data 0000100, data(14), 0
Read Data 0001000, data(14), 0
Increment Address 000110
Begin programming 001000
End Programming 001110
Note: The clock must be disabled during In-Circuit Serial Programming.
PIC16C6XX/7XX/9XX
DS30228J-page 3-56 2000 Microchip Technology Inc.
FIGURE 2-2: PROGRAM FLOW CHART - PIC16C6XX/7XX/9XX PROGRAM MEMORY
* VDDP = VDD range for programming (typically 4.75V - 5.25V).
VDDmin = Minimum VDD for device operation.
VDDmax = Maximum VDD for device operation.
Start
N = 1
Set VDD = VDDP*
Program Cycle
Read Data
Command
Data correct?
Apply 3N Additional
Program Cycles
All locations done?
Verify all locations
@ VDD min.*
VPP = VIHH2
Data correct?
Verify all locations
@ VDD max.*
VPP = VIHH2
Data correct?
Done
N > 25? Report programming
failure
N = N + 1 N = #
of Program Cycles
Increment Address
Command
Report verify
@ VDD min. Error
Report verify
@ VDD max. Error
Load Data
Command
Begin Programming
Command
End Programming
Command
Wait 100 µs
Program Cycle
Ye s
No
No
Ye s
No
Ye s
No
No
Ye s
Ye s
Set VPP = VIHH1
2000 Microchip Technology Inc. DS30228J-page 3-57
PIC16C6XX/7XX/9XX
FIGURE 2-3: PROGRAM FLOW CHART - PIC16C6XX/7XX/9XX CONFIGURATION WORD & ID
LOCATIONS
VDDmin
VDDmax
Start
Load Configuration
Command
Increment Address
Command N = N + 1 N = #
of Program Cycles
Report ID
Configuration Error
Increment Address
Command
Increment Address
Command
Increment Address
Command
Program Cycle
100 Cycles
Read Data
Command
Apply 3N
Program Cycles
Read Data
Command
Report Program
ID/Config. Error
Set VDD = VDDmax
Program Cycle
N = 1
Data Correct?
Data Correct?
Data Correct?
Data Correct?
N > 25
Address = 2004
Program ID Loc?
Done
Ye s
No
No
Ye s
No
Ye s
Ye s
Ye s
No
Ye s
No
No
No Yes
Read Data Command
Set VPP = VIHH2
Set VDD = VDDmin
Read Data Command
Set VPP = VIHH2
Set VDD = VDDP*
Set VPP = VIHH1
VDDP = VDD Range for programming (Typically 4.25V – 5.25V)
VDDMIN = minimum VDD for device operation
VDDMAX = maximum VDD for device operation
PIC16C6XX/7XX/9XX
DS30228J-page 3-58 2000 Microchip Technology Inc.
2.2.1.2 LOAD DATA
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 4-1.
2.2.1.3 READ DATA
After receiving this command, the chip will transmit
data bits out of the memory currently accessed starting
with the second rising edge of the clock input. The RB7
pin will go into output mode on the second rising clock
edge, and it will revert back to input mode (hi-imped-
ance) after the 16th rising edge. A timing diagram of
this command is shown in Figure 4-2.
2.2.1.4 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 4-3.
2.2.1.5 BEGIN PROGRAMMING
A load command (load configuration or load data)
must be given before every begin programming
command. Programming of the appropriate memory
(test program memory or user program memory) will
begin after this command is received and decoded.
Programming should be performed with a series of
100µs programming pulses. A programming pulse is
defined as the time between the begin programming
command and the end programming command.
2.2.1.6 END PROGRAMMING
After receiving this command, the chip stops program-
ming the memory (configuration program memory or
user program memory) that it was programming at the
time.
2.3 Programming Algorithm Requires
Variable VDD
The PIC16C6XX/7XX/9XX uses an intelligent algo-
rithm. The algorithm calls for program verification at
VDDmin as well as VDDmax. Verification at VDDmin
guarantees good “erase margin”. Verification at
VDDmax guarantees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (4.75 - 5.25V).
VDDP =VCC range required during programming.
VDD min. = minimum operating VDD spec for the part.
VDDmax = maximum operating VDD spec for the part.
Programmers must verify the PIC16C6XX/7XX/9XX at
its specified VDDmax and VDDmin levels. Since
Microchip may introduce future versions of the
PIC16C6XX/7XX/9XX with a broader VDD range, it is
best that these levels are user selectable (defaults are
ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
2000 Microchip Technology Inc. DS30228J-page 3-59
PIC16C6XX/7XX/9XX
3.0 CONFIGURATION WORD
The PIC16C6XX/7XX/9XX family members have sev-
eral configuration bits. These bits can be programmed
(reads ’0’) or left unprogrammed (reads ’1’) to select
various device configurations. Figure 3-1 and
Figure 3-2 provides an overview of configuration bits.
PIC16C6XX/7XX/9XX
DS30228J-page 3-60 2000 Microchip Technology Inc.
FIGURE 3-1: CONFIGURATION WORD BIT MAP
Bit
Number: 13 12 11 10 9 8 7 6543 2 1 0
PIC16C61/71 ——————— — —CP0 PWRTE WDTE FOSC1 FOSC0
PIC16C62/64/65/73/74 ——————— 0 CP1 CP0 PWRTE WDTE FOSC1 FOSC0
PIC16C62A/62B/63A/CR62/
63/
64A/CR64/65A/65B/66/67/
72/72A/73A/73B/74A/74B/76/
77/620/620A/621/621A/622/
622A/
712/716 CP1 CP0 CP1 CP0 CP1 CP0 —BODEN CP1 CP0 PWRTE WDTE FOSC1 FOSC0
PIC16C9XX/745/765 CP1 CP0 CP1 CP0 CP1 CP0 ——CP1 CP0 PWRTE WDTE FOSC1 FOSC0
Reserved, '–' write as '1' for PIC16C6XX/7XX/9XX
CP <1:0>, Code Protect
bit 6: BODEN, Brown Out Enable Bit
1 = Enabled
2 = Disable
bit 4: PWRTE/PWRTE, Power Up Timer Enable Bit
PIC16C61/62/64/65/71/73/74:
1 = Power up timer enabled
0 = Power up timer disabled
PIC16C620/620A/621/621A/622/622A/62A/63/63A/65A/65B/66/67/72/72A/73A/73B/74A/74B/76/77/710/
711/923/924/745/765:
0 = Power up timer enabled
1 = Power up timer disabled
bit 3-2: WDTE, WDT Enable Bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC<1:0>, Oscillator Selection Bit
11: RC oscillator
10: HS oscillator
01: XT oscillator
00: LP oscillator
bit 1-0: FOSC<1:0>, PIC16C745/765
11: E external clock with 4k PLL
10: H HS oscillator with 4k PL enabled
01: EC external clock, clkout on osc2
00: HS
Note 1: Enabling Brown-out Reset automatically enables the Power-up Timer (PWRT) regardless of the value of bit
PWRTE. Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
Device CP1 CP0 Code Protection
PIC16C622/622A
PIC16C62/62A/62B 0 0 All memory protected
PIC16C63/63A
PIC16C64/64A/712/716 0 1 Upper 3/4 memory protected
PIC16C65/65A/65B
PIC16C66/67/72/72A 1 0 Upper 1/2 memory protected
PIC16C73/73A/73B
PIC16C74/74A/74B/76/77
PIC16C745/765
PIC16C9XX
1 1 Code protection off
PIC16C61/71
PIC16C710/711
—0 All memory protected
—1Off
PIC16C620 0 0 All memory protected
0 1 Do not use
1 0 Do not use
1 1 Code protection off
PIC16C621 0 0 All memory protected
1 0 Upper 1/2 memory protected
1 1 Code protection off
2000 Microchip Technology Inc. DS30228J-page 3-61
PIC16C6XX/7XX/9XX
FIGURE 3-2: CONFIGURATION WORD FOR PIC16C773/774 DEVICE
CP1 CP0 BORV1 BORV0 CP1 CP0 - BODEN CP1 CP0 PWRTE WDTE FOSC1 FOSC0 Register: CONFIG
Address 2007h
bit13 12 11 10 9 8 7 6 5 4 3 2 1 bit0
CP <1:0> Code Protection bits (2)
bit 11-10: BORV <1:0>: Brown-out Reset Voltage bits
11 = VBOR set to 2.5V
10 = VBOR set to 2.7V
01 = VBOR set to 4.2V
00 = VBOR set to 4.5V
bit 7: Unimplemented, Read as ’1’
bit 6: BODEN: Brown-out Reset Enable bit (1)
1 = Brown-out Reset enabled
0 = Brown-out Reset disabled
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC <1:0>: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Note 1: Enabling Brown-out Reset automatically enables the Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP <1:0> pairs have to be given the same value to enable the code protection scheme listed.
Device CP1 CP0 Code Protection
PIC16C773/774 0 0 All memory protected
0 1 Upper 3/4 memory protected
1 0 Upper 1/2 memory protected1
1 1 Code protection off
PIC16C6XX/7XX/9XX
DS30228J-page 3-62 2000 Microchip Technology Inc.
FIGURE 3-3: CONFIGURATION WORD, PIC16C710/711
CP0 CP0 CP0 CP0 CP0 CP0 CP0 BODEN CP0 CP0 PWRTE WDTE FOSC1 FOSC0 Register: CONFIG
Address 2007h
bit13 bit0
bit 13-7 CP0: Code protection bits (2)
5-4: 1 = Code protection off
0 = All memory is code protected, but 00h - 3Fh is writable
bit 6: BODEN: Brown-out Reset Enable bit (1)
1 = BOR enabled
0 = BOR disabled
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC <1:0>: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP0 bits have to be given the same value to enable the code protection scheme listed.
2000 Microchip Technology Inc. DS30228J-page 3-63
PIC16C6XX/7XX/9XX
3.1 Embedding Configuration Word and ID Information in the Hex File.
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Microchip Technology Inc. feels strongly that this feature is beneficial to the end customer.
PIC16C6XX/7XX/9XX
DS30228J-page 3-64 2000 Microchip Technology Inc.
3.2 Checksum
3.2.1 CHECKSUM CALCULATIONS
Checksum is calculated by reading the contents of the
PIC16C6XX/7XX/9XX memory locations and adding
up the opcodes up to the maximum user addressable
location, e.g., 0x1FF for the PIC16C74. Any carry bits
exceeding 16-bits are neglected. Finally, the configura-
tion word (appropriately masked) is added to the check-
sum. Checksum computation for each member of the
PIC16C6XX/7XX/9XX devices is shown in Table 3-1.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 3-1: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
PIC16C61 OFF
ON
SUM[0x000:0x3FF] + CFGW & 0x001F + 0x3FE0
SUM_XNOR7[0x000:0x3FF] + (CFGW & 0x001F | 0x0060)
0x3BFF
0xFC6F
0x07CD
0xFC15
PIC16C620 OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3F7F
SUM_ID + CFGW & 0x3F7F
0x3D7F
0x3DCE
0x094D
0x099C
PIC16C620A OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3F7F
SUM_ID + CFGW & 0x3F7F
0x3D7F
0x3DCE
0x094D
0x099C
PIC16C621 OFF
1/2
ALL
SUM[0x000:0x3FF] + CFGW & 0x3F7F
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x3B7F
0x4EDE
0x3BCE
0x074D
0x0093
0x079C
PIC16C621A OFF
1/2
ALL
SUM[0x000:0x3FF] + CFGW & 0x3F7F
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x3B7F
0x4EDE
0x3BCE
0x074D
0x0093
0x079C
PIC16C622 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C622A OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16CE623 OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3F7F
SUM_ID + CFGW & 0x3F7F
0x3D7F
0x3DCE
0x094D
0x099C
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_XNOR7[a:b] = XNOR of the seven high order bits of memory location with the seven low order bits summed over
locations a through b inclusive. For example, XNOR(0x3C31)=0x78 XNOR 0c31 = 0x0036.
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble. For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
| = Bitwise OR
2000 Microchip Technology Inc. DS30228J-page 3-65
PIC16C6XX/7XX/9XX
PIC16CE624 OFF
1/2
ALL
SUM[0x000:0x3FF] + CFGW & 0x3F7F
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x3B7F
0x4EDE
0x3BCE
0x074D
0x0093
0x079C
PIC16CE625 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C62 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x003F + 0x3F80
SUM[0x000:0x3FF] + SUM_XNOR7[0x400:0x7FF] + CFGW & 0x003F +
0x3F80
SUM[0x000:0x1FF] + SUM_XNOR7[0x200:0x7FF] + CFGW & 0x003F +
0x3F80
SUM_XNOR7[0x000:0x7FF] + CFGW & 0x003F + 0x3F80
0x37BF
0x37AF
0x379F
0x378F
0x038D
0x1D69
0x1D59
0x3735
PIC16C62A OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C62B OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C63 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C63A OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C64 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x003F + 0x3F80
SUM[0x000:0x3FF] + SUM_XNOR7[0x400:0x7FF] + CFGW & 0x003F +
0x3F80
SUM[0x000:0x1FF] + SUM_XNOR7[0x200:0x7FF] + CFGW & 0x003F +
0x3F80
SUM_XNOR7[0x000:0x7FF] + CFGW & 0x003F + 0x3F80
0x37BF
0x37AF
0x379F
0x378F
0x038D
0x1D69
0x1D59
0x3735
PIC16C64A OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C65 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
SUM[0x000:0x7FF] + SUM_XNOR7[0x800:FFF] + CFGW & 0x003F +
0x3F80
SUM[0x000:0x3FF] + SUM_XNOR7[0x400:FFF] + CFGW & 0x003F +
0x3F80
SUM_XNOR7[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
0x2FBF
0x2FAF
0x2F9F
0x2F8F
0xFB8D
0x1569
0x1559
0x2F35
TABLE 3-1: CHECKSUM COMPUTATION (CONTINUED)
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_XNOR7[a:b] = XNOR of the seven high order bits of memory location with the seven low order bits summed over
locations a through b inclusive. For example, XNOR(0x3C31)=0x78 XNOR 0c31 = 0x0036.
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble. For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
| = Bitwise OR
PIC16C6XX/7XX/9XX
DS30228J-page 3-66 2000 Microchip Technology Inc.
PIC16C65A OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C65B OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C66 OFF
1/2
3/4
ALL
SUM[0x000:0x1FFF] + CFGW & 0x3F7F
SUM[0x000:0xFFF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x1F7F
0x39EE
0x2CDE
0x1FCE
0xEB4D
0xEBA3
0xDE93
0xEB9C
PIC16C67 OFF
1/2
3/4
ALL
SUM[0x000:0x1FFF] + CFGW & 0x3F7F
SUM[0x000:0xFFF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x1F7F
0x39EE
0x2CDE
0x1FCE
0xEB4D
0xEBA3
0xDE93
0xEB9C
PIC16C710 OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3FFF
SUM[0x00:0x3F] + CFGW & 0x3FFF + SUM_ID
0x3DFF
0x3E0E
0x09CD
0xEFC3
PIC16C71 OFF
ON
SUM[0x000:0x3FF] + CFGW & 0x001F + 0x3FE0
SUM_XNOR7[0x000:0x3FF] + (CFGW & 0x001F | 0x0060)
0x3BFF
0xFC6F
0x07CD
0xFC15
PIC16C711 OFF
ON
SUM[0x000:0x03FF] + CFGW & 0x3FFF
SUM[0x00:0x3FF] + CFGW & 0x3FFF + SUM_ID
0x3BFF
0x3C0E
0x07CD
0xEDC3
PIC16C712 OFF
1/2
ALL
SUM[0x000:0x07FF] + CFGW & 0x3F7F
SUM[0x000:0x03FF] + CFGW & 3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x37CE
0x034D
0xF58A
0x039C
PIC16C716 OFF
1/2
3/4
ALL
SUM[0x000:0x07FF] + CFGW & 0x3F7F
SUM[0x000:0x03FF] + CFGW & 0x3F7F + SUM_ID
SUM]0x000:0x01FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C72 OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C72A OFF
1/2
3/4
ALL
SUM[0x000:0x7FF] + CFGW & 0x3F7F
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x1FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x377F
0x5DEE
0x4ADE
0x37CE
0x034D
0x0FA3
0xFC93
0x039C
PIC16C73 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
SUM[0x000:0x7FF] + SUM_XNOR7[0x800:FFF] + CFGW & 0x003F +
0x3F80
SUM[0x000:0x3FF] + SUM_XNOR7[0x400:FFF] + CFGW & 0x003F +
0x3F80
SUM_XNOR7[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
0x2FBF
0x2FAF
0x2F9F
0x2F8F
0xFB8D
0x1569
0x1559
0x2F35
PIC16C73A OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
TABLE 3-1: CHECKSUM COMPUTATION (CONTINUED)
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_XNOR7[a:b] = XNOR of the seven high order bits of memory location with the seven low order bits summed over
locations a through b inclusive. For example, XNOR(0x3C31)=0x78 XNOR 0c31 = 0x0036.
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble. For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
| = Bitwise OR
2000 Microchip Technology Inc. DS30228J-page 3-67
PIC16C6XX/7XX/9XX
PIC16C73B OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C74 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
SUM[0x000:0x7FF] + SUM_XNOR7[0x800:FFF] + CFGW & 0x003F +
0x3F80
SUM[0x000:0x3FF] + SUM_XNOR7[0x400:FFF] + CFGW & 0x003F +
0x3F80
SUM_XNOR7[0x000:0xFFF] + CFGW & 0x003F + 0x3F80
0x2FBF
0x2FAF
0x2F9F
0x2F8F
0xFB8D
0x1569
0x1559
0x2F35
PIC16C74A OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C74B OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F7F
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x51EE
0x40DE
0x2FCE
0xFB4D
0x03A3
0xF293
0xFB9C
PIC16C76 OFF
1/2
3/4
ALL
SUM[0x000:0x1FFF] + CFGW & 0x3F7F
SUM[0x000:0xFFF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x1F7F
0x39EE
0x2CDE
0x1FCE
0xEB4D
0xEBA3
0xDE93
0xEB9C
PIC16C77 OFF
1/2
3/4
ALL
SUM[0x000:0x1FFF] + CFGW & 0x3F7F
SUM[0x000:0xFFF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:0x7FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x1F7F
0x39EE
0x2CDE
0x1FCE
0xEB4D
0xEBA3
0xDE93
0xEB9C
PIC16C773 OFF
1/2
3/4
ALL
SUM[0x000:0x0FFF] + CFGW & 0x3F7F
SUM[0x000:07FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:03FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0x55EE
0x48DE
0x3BCE
0xFB4D
0x07A3
0xFA93
0x079C
PIC16C774 OFF
1/2
3/4
ALL
SU:M[0x000:0FFF] + CFGW & 0x3F7F
SUM[0x000:07FF] + CFGW & 0x3F7F + SUM_ID
SUM[0x000:03FF] + CFGW & 0x3F7F + SUM_ID
CFGW & 0x3F7F + SUM_ID
0x2F7F
0X55EE
0X48DE
0x3BCE
0xFB4D
0x07A3
0xFA93
0X079C
PIC16C923 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F3F
SUM[0x000:0x7FF] + CFGW & 0x3F3F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F3F + SUM_ID
CFGW & 0x3F3F + SUM_ID
0x2F3F
0x516E
0x405E
0x2F4E
0xFB0D
0x0323
0xF213
0xFB1C
PIC16C924 OFF
1/2
3/4
ALL
SUM[0x000:0xFFF] + CFGW & 0x3F3F
SUM[0x000:0x7FF] + CFGW & 0x3F3F + SUM_ID
SUM[0x000:0x3FF] + CFGW & 0x3F3F + SUM_ID
CFGW & 0x3F3F + SUM_ID
0x2F3F
0x516E
0x405E
0x2F4E
0xFB0D
0x0323
0xF213
0xFB1C
PIC16C745 OFF
1000:1FFF
800:1FFF
ALL
SUM(0000:1FFF) + CFGW & 0x3F3F
SUM(0000:0FFF) + CFGW & 0x3F3F+SUM_ID
SUM(0000:07FF) + CFGW & 0x3F3F + SUM_ID
CFGW * 0x3F3F + SUM_ID
1F3F
396E
2C5E
1F4E
EB0D
EB23
DE13
EB1C
TABLE 3-1: CHECKSUM COMPUTATION (CONTINUED)
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_XNOR7[a:b] = XNOR of the seven high order bits of memory location with the seven low order bits summed over
locations a through b inclusive. For example, XNOR(0x3C31)=0x78 XNOR 0c31 = 0x0036.
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble. For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
| = Bitwise OR
PIC16C6XX/7XX/9XX
DS30228J-page 3-68 2000 Microchip Technology Inc.
PIC16c765 OFF
1000:1FFF
800:1FFF
ALL
SUM(0000:1FFF) + CFGW & 0x3F3F
SUM(0000:0FFF) + CFGW & 0x3F3F+SUM_ID
SUM(0000:07FF) + CFGW & 0x3F3F + SUM_ID
CFGW * 0x3F3F + SUM_ID
1F3F
396E
2C5E
1F4E
EB0D
EB23
DE13
EB1C
TABLE 3-1: CHECKSUM COMPUTATION (CONTINUED)
Device Code
Protect Checksum* Blank
Value
0x25E6 at
0 and max
address
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a through b inclusive]
SUM_XNOR7[a:b] = XNOR of the seven high order bits of memory location with the seven low order bits summed over
locations a through b inclusive. For example, XNOR(0x3C31)=0x78 XNOR 0c31 = 0x0036.
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble. For example,
ID0 = 0x12, ID1 = 0x37, ID2 = 0x4, ID3 = 0x26, then SUM_ID = 0x2746.
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
| = Bitwise OR
2000 Microchip Technology Inc. DS30228J-page 3-69
PIC16C6XX/7XX/9XX
4.0 PROGRAM/VERIFY MODE
TABLE 4-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (20°C recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions
General
PD1 VDDP Supply voltage during programming 4.75 5.0 5.25 V
PD2 IDDP Supply current (from VDD)
during programming
––20 mA
PD3 VDDV Supply voltage during verify VDDmin –VDDmax V Note 1
PD4 VIHH1 Voltage on MCLR/VPP during
programming
12.75 –13.25 V Note 2
PD5 VIHH2 Voltage on MCLR/VPP during verify VDD + 4.5 –13.25 –
PD6 IPP Programming supply current (from
VPP)
––50 mA
PD9 VIH (RB6, RB7) input high level 0.8 VDD –– V Schmitt Trigger input
PD8 VIL (RB6, RB7) input low level 0.2 VDD –– V Schmitt Trigger input
Serial Program Verify
P1 TRMCLR/VPP rise time (VSS to VHH)
for test mode entry
––8.0 µs
P2 Tf MCLR Fall time ––8.0 µs
P3 Tset1 Data in setup time before clock ↓ 100 ––ns
P4 Thld1 Data in hold time after clock ↓ 100 ––ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 ––µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 ––µs
P7 Tdly3 Clock ↑ to date out valid
(during read data)
200 ––ns
P8 Thld0 Hold time after MCLR ↑2––µs
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
PIC16C6XX/7XX/9XX
DS30228J-page 3-70 2000 Microchip Technology Inc.
FIGURE 4-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 4-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 4-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
0
0
0
1µs min.
P5
1µs min.
P6
0
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR/VPP
}
}
P4
100ns
min.
P3
}
00
1µs min.
P5
1µs min.
P6
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR/VPP
RB7 = output RB7
input
P7
}
}
}
0
000
00
11
12345 61
2
100ns
min
P3 P4
P6
1µs min. Next Command
P5
1µs min.
VIHH
MCLR/VPP
RB6
(CLOCK)
(DATA)
RB7
Reset
Program/Verify Test Mode
2000 Microchip Technology Inc. DS30274B-page 3-71
PIC17C7XX
This document includes the programming
specifications for the following devices:
• PIC17C752
• PIC17C756
• PIC17C756A
• PIC17C762
• PIC17C766
1.0 PROGRAMMING THE
PIC17C7XX
The PIC17C7XX is programmed using the TABLWT
instruction. The table pointer points to the internal
EPROM location start. Therefore, a user can program
an EPROM location while executing code (even from
internal EPROM). This programming specification
applies to PIC17C7XX devices in all packages.
For the convenience of a programmer developer, a
“program & verify” routine is provided in the on-chip test
program memory space. The program resides in ROM
and not EPROM, therefore, it is not erasable. The “pro-
gram/verify” routine allows the user to load any
address, program a location, verify a location or incre-
ment to the next location. It allows variable program-
ming pulse width.
The PIC17C7XX group of the High End Family has
added a feature that allows the serial programming of
the device. This is very useful in applications where it is
desirable to program the device after it has been man-
ufactured into the users system (In-circuit Serial Pro-
gramming (ISP)). This allows the product to be shipped
with the most current version of the firmware, since the
microcontroller can be programmed just before final
test as opposed to before board manufacture. Devices
may be serialized to make the product unique, “special”
variants of the product may be offered, and code
updates are possible. This allows for increased design
flexibility.
1.1 Hardware Requirements
Since the PIC17C7XX under programming is actually
executing code from “boot ROM,” a clock must be pro-
vided to the part. Furthermore, the PIC17C7XX under
programming may have any oscillator configuration
(EC, XT, LF or RC). Therefore, the external clock driver
must be able to overdrive pulldown in RC mode. CMOS
drivers are required since the OSC1 input has a
Schmitt trigger input with levels (typically) of 0.2 VDD
and 0.8 VDD. See the PIC17C7XX data sheet
(DS30289) for exact specifications.
The PIC17C7XX requires two programmable power
supplies, one for VDD (3.0V to 5.5V recommended) and
one for VPP (13 ± 0.25V). Both supplies should have a
minimum resolution of 0.25V.
The PIC17C7XX uses an intelligent algorithm. The
algorithm calls for program verification at VDDmin as
well as VDDmax. Verification at VDDmin guarantees
good “erase margin”. Verification at VDDmax guaran-
tees good “program margin.” Three times (3X)
additional pulses will increase program margin beyond
VDDmax and insure safe operation in user system.
The actual programming must be done with VDD in the
VDDP range (Parameter PD1).
VDDP = VDD range required during programming.
VDDmin. = minimum operating VDD spec. for the part.
VDDmax. = maximum operating VCC spec for the part.
Programmers must verify the PIC17C7XX at its speci-
fied VDDmax and VDDmin levels. Since Microchip may
introduce future versions of the PIC17C7XX with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok). Blank checks should be
performed at VDDMIN.
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
In-Circuit Serial Programming for PIC17C7XX OTP MCUs
PIC17C7XX
DS30274B-page 3-72 2000 Microchip Technology Inc.
FIGURE 1-1: PIC17C752/756/756A/762/766 LCC
TABLE 1-1: PIN DESCRIPTIONS (DURING PROGRAMMING IN PARALLEL MODE): PIC17C7XX
Pin Name
During Programming
Pin Name Pin Type Pin Description
RA4:RA0 RA4:RA0 I Necessary in programming mode
TEST TEST I Must be set to “high” to enter programming mode
PORTB<7:0> DAD15:DAD8 I/O Address & data: high byte
PORTC<7:0> DAD7:DAD0 I/O Address & data: low byte
MCLR/VPP VPP P Programming Power
VDD VDD P Power Supply
VSS VSS P Ground
Legend: I = Input, O = Output, P = Power
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
9876543216867666564636261
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
Top View
RA0/INT
RB0/CAP1
RB1/CAP2
RB3/PWM2
RB4/TCLK12
RB5/TCLK3
RB2/PWM1
V
SS
NC
OSC2/CLKOUT
OSC1/CLKIN
V
DD
RB7/SDO
RA3/SDI/SDA
RA2/SS/SCL
RA1/T0CKI
RD1/AD9
RD0/AD8
RE0/ALE
RE1/OE
RE2/WR
RE3/CAP4
MCLR/V
PP
TEST
V
SS
V
DD
RF7/AN11
RF6/AN10
RF5/AN9
RF4/AN8
RF3/AN7
RF2/AN6
RD2/AD10
RD3/AD11
RD4/AD12
RD5/AD13
RD6/AD14
RD7/AD15
RC0/AD0
V
DD
NC
V
SS
RC1/AD1
RC2/AD2
RC3/AD3
RC4/AD4
RC5/AD5
RC6/AD6
RC7/AD7
RF1/AN5
RF0/AN4
AV
DD
AV
SS
RG3/AN0/V
REF
+
RG2/AN1/V
REF
-
RG1/AN2
RG0/AN3
NC
V
SS
V
DD
RG4/CAP3
RG5/PWM3
RG7/TX2/CK2
RG6/RX2/DT2
RA4/RX1/DT1
RA5/TX1/CK1
NC
RB6/SCK
RF1/AN5
RF0/AN4
AV
DD
AV
SS
RG3/AN0/V
REF
+
RG2/AN1/V
REF
-
RG1/AN2
RG0/AN3
NC
V
SS
V
DD
RG4/CAP3
RG5/PWM3
RG7/TX2/CK2
RG6/RX2/DT2
RA4/RX1/DT1
RA5/TX1/CK1
RJ0
RJ1
RH6/AN14
RH7/AN15
RD1/AD9
RD0/AD8
RE0/ALE
RE1/OE
RE2/WR
RE3/CAP4
MCLR/V
PP
TEST
V
SS
V
DD
RF7/AN11
RF6/AN10
RF5/AN9
RF4/AN8
RF3/AN7
RF2/AN6
NC
RH2
RH3
RH4/AN12
RH5/AN13
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26 60
59
58
57
56
55
54
5352
51
50
4948
474645
44
987654321
27
28
29
30
31
32
3334353637383940414243
Top View
RA0/INT
RB0/CAP1
RB1/CAP2
RB3/PWM2
RB4/TCLK12
RB5/TCLK3
RB2/PWM1
V
SS
NC
OSC2/CLKOUT
OSC1/CLKIN
V
DD
RB7/SDO
RA3/SDI/SDA
RA2/SS/SCL
RA1/T0CKI
RD2/AD10
RD3/AD11
RD4/AD12
RD5/AD13
RD6/AD14
RD7/AD15
RC0/AD0
V
DD
NC
V
SS
RC1/AD1
RC2/AD2
RC3/AD3
RC4/AD4
RC5/AD5
RC6/AD6
RC7/AD7
RB6/SCK
RJ5
RJ4
RJ7
RJ6
RJ3
RJ2
RH1
RH0
67
66
65
64
63
62
61
68
74
73
72
71
70
76
79787780
838281
84 75
69
PIC17C762/766
PIC17C752/756/756A
2000 Microchip Technology Inc. DS30274B-page 3-73
PIC17C7XX
2.0 PARALLEL MODE PROGRAM
ENTRY
To execute the programming routine, the user must hold
TEST pin high, RA2, RA3 must be low and RA4 must
be high (after power-up) while keeping MCLR low and
then raise MCLR pin from VIL to VDD or VPP. This will
force FFE0h in the program counter and execution will
begin at that location (the beginning of the boot code)
following reset.
All unused pins during programming are in hi-imped-
ance state.
PORTB (RB pins) has internal weak pull-ups which are
active during the programming mode. When the TEST
pin is high, the Power-up timer (PWRT) and Oscillator
Start-up Timers (OST) are disabled.
2.1 Program/Verify Mode
The program/verify mode is intended for full-feature
programmers. This mode offers the following capabili-
ties:
a) Load any arbitrary 16-bit address to start pro-
gram and/or verify at that location.
b) Increment address to program/verify the next
location.
c) Allows arbitrary length programming pulse width.
d) Following a “verify” allows option to program the
same location or increment and verify the next
location.
e) Following a “program” allows options to program
the same location again, verify the same loca-
tion or to increment and verify the next location.
FIGURE 2-1: PROGRAMMING/VERIFY STATE DIAGRAM
Note: The Oscillator must not have 72 OSC
clocks while the device MCLR is between
VIL and VIHH.
Reset
Jump to
Program
Routine
Load
Address Reset
Pulse
RA1
Pulse
RA1
Pulse RA1
(Raise RA1
after RA0↓)
RA0↑
Program
Raise RA1
before RA0↓
Pulse RA0
(RA0 pulse
width is
programming time)
Increment
Address
Pulse
RA1
PIC17C7XX
DS30274B-page 3-74 2000 Microchip Technology Inc.
2.1.1 LOADING NEW ADDRESS
The program allows new address to be loaded right out
of reset. A 16-bit address is presented on ports B (high
byte) and C (low byte) and the RA1 is pulsed (0 →1,
then 1 →0). The address is latched on the rising edge
of RA1. See timing diagrams for details. After loading
an address, the program automatically goes into a “ver-
ify cycle.” To load a new address at any time, the
PIC17C7XX must be reset and the programming mode
re-entered.
2.1.2 VERIFY (OR READ) MODE
“Verify mode” can be entered from “Load address”
mode, “program mode” or “verify mode.” In verify mode
pulsing RA1 will turn on PORTB and PORTC output
drivers and output the 16-bit value from the current
location. Pulsing RA1 again will increment location
count and be ready for the next verify cycle. Pulsing
RA0 will begin a program cycle.
2.1.3 PROGRAM CYCLE
“Program cycle” is entered from “verify cycle” or pro-
gram cycle” itself. After a verify, pulsing RA0 will begin
a program cycle. 16-bit data must be presented on
PORTB (high byte) and PORTC (low byte) before RA0
is raised.
The data is sampled 3 TCY cycles after the rising edge
of RA0. Programming continues for the duration of RA0
pulse.
At the end of programming, the user can choose one of
three different routes. If RA1 is kept low and RA0 is
pulsed again, the same location will be programmed
again. This is useful for applying over programming
pulses. If RA1 is raised before RA0 falling edge, then a
verify cycle is started without address increment. Rais-
ing RA1 after RA0 goes low will increment address and
begin verify cycle on the next address.
FIGURE 2-2: PIC17C7XX PROGRAM MEMORY MAP
FOSC0
FOSC1
WDTPS0
WDTPS1
PM0
PM1
PM2
Reserved
Reserved
Reserved
FE00h
FE01h
FE02h
FE03h
FE04h
FE05h
FE06h
FE07h
FE08h
FE09h
FE0Fh
Reserved
BODENFE0Eh
On-chip
Program
EPROM
Configuration
Word
0000h
1FFFh
FE00h
FE0Fh
FFFFh
On-chip
Program
EPROM
Configuration
Word
On-chip
Program
EPROM
Configuration
Word
On-chip
Program
EPROM
Configuration
Word
PIC17C752 PIC17C756/756A PIC17C762 PIC17C766
3FFFh
2000 Microchip Technology Inc. DS30274B-page 3-75
PIC17C7XX
3.0 PARALLEL MODE PROGRAMMING SPECIFICATIONS
FIGURE 3-1: PROGRAMMING ROUTINE FLOWCHART
RESET
RA2 = 0
RA3 = 0
RA4 = 1
MCLR = 1
Bport = 0xE1
(hold for 10 TCY)
Present address
on ports RB, RC
hold TCY after
RA1 changes
to 1
RA1 = 0
RA1 = 1
Stop driving
address on ports
RA1 = 0
RA1 = 1
B port =
MSB of Data
C port =
LSB of Data
Read MSB of data
from portB.
Read LSB of data
from portC
Enable RA0 to end
program cycle
Program
16-bit
data
RA0 = 0
RA1 = 0
Bport = xxx
Bport = xxx
RA1 = 0
RA1 = 1
RA1 = 0
B and C
ports not
driven by part
If programming is desired
force portB = MSB of data
force portC = LSB of data
(hold 10 Tcy after RA0
is raised)
RA0 = 1
RA1 = 1
Increment
Address
YES
YES
YES
YES
NO
NO
NO
NO
YES
YES
YES
NO
NO
NO
NO
NO
RA0 = 1
RA1 = 1
NO
NO
YES YES
YES
YES
YES
NO
NO
- B port is forced by the part
- B port tristate, should be forced by user
Min RA + high or low = 10 TCY
PIC17C7XX
DS30274B-page 3-76 2000 Microchip Technology Inc.
FIGURE 3-2: RECOMMENDED PROGRAMMING ALGORITHM FOR USER EPROM
Apply (3x Pulse-count)
more 100 µs programming
pulses for margin
(Over programming)
Start
Load new address
Pulse-count = 0
Set VDD = VDDMIN
Verify blank
Pulse
Blank
Check?
Load new data
Set VDD to VDDP
Program using 100 µs
pulse increment
pulse-count
Verify location
for correct date
Pass?
Pulse-
Count
>25
Location fails
programming issue error
message “Unable to
programming location”
Issue “Blank check fail”
error message
Pass?
Set VDD = VDDMIN
verify location
Set VDD = VDDMIN
verify location(s)
Program error message
Issue error message
“Fail verify @ VDDMIN/MAX”
Set VDD = VDDMIN
YES
NO
NO
YES
YES
NO
NO
YES
2000 Microchip Technology Inc. DS30274B-page 3-77
PIC17C7XX
FIGURE 3-3: RECOMMENDED PROGRAMMING ALGORITHM FOR CONFIGURATION WORDS
Load new address
Pulse-count = 0
Set VDD = VDDmin
Verify blank
Issue “blank check fail”
Load new data
Set VDD = VDDP
Set VDD = VDDmax
Set VDD = VDDmin
Verify location for
Program using 100 µs
Location fails
Programming error:
NO
YES
NO
NO
YES
YES
Start
Pass
Blank
check?
pulse increment
pulse-count
Pass?
Issue error message
“Fail verify @ VDDmin/max”
Verify location(s)
Pass?
NO
YES Pulse
count
<100
programming, issue error
message “Unable to
program location”
correct data
error message
Set VDD = VDDMIN
Set VDD = VDDmin
Verify location
PIC17C7XX
DS30274B-page 3-78 2000 Microchip Technology Inc.
4.0 SERIAL MODE PROGRAM
ENTRY
4.1 Hardware Requirements
Certain design criteria must be taken into account for
ISP. Seven pins are required for the interface. These
are shown in Table 4-1.
4.2 Serial Program Mode Entry
To place the device into the serial programming test
mode, two pins will need to be placed at VIHH. These
are the TEST pin and the MCLR/VPP pins. Also, the fol-
lowing sequence of events must occur:
1. The TEST pin is placed at VIHH.
2. The MCLR/VPP pin is placed at VIHH.
There is a setup time between step 1 and step 2 that
must be meet (See “Electrical Specifications for Serial
Programming Mode” on page 93.)
After this sequence the Program Counter is pointing to
Program Memory Address 0xFF60. This location is in
the Boot ROM. The code initializes the USART/SCI so
that it can receive commands. For this the device must
be clocked. The device clock source in this mode is the
RA1/T0CKI pin. Once the USART/SCI has been initial-
ized, commands may be received. The flow is show in
these 3 steps:
1. The device clock source starts.
2. Wait 80 device clocks for Boot ROM code
to configure the USART/SCI.
3. Commands may be sent now.
TABLE 4-1: ISP Interface Pins
During Programming
Name Function Type Description
RA4/RX/DT DT I/O Serial Data
RA5/TX/CK CK I Serial Clock
RA1/T0CKI OSCI I Device Clock Source
TEST TEST I Test mode selection control input. Force to VIHH,
MCLR/VPP MCLR/VPP P Programming Power
VDD VDD P Power Supply
VSS VSS P Ground
2000 Microchip Technology Inc. DS30274B-page 3-79
PIC17C7XX
4.3 Software Commands
This feature is similar to that of the PIC16CXXX mid-
range family, but the programming commands have
been implemented in the device Boot ROM. The Boot
ROM is located in the program memory from 0xFF60 to
0xFFFF. The ISP mode is entered when the TEST pin
has a VIHH voltage applied. Once in ISP mode, the
USART/SCI module is configured as a synchronous
slave receiver, and the device waits for a command to
be received. The ISP firmware recognizes eight com-
mands. These are shown in Table 4-2.
TABLE 4-2: ISP COMMANDS
4.3.1 RESET PROGRAM MEMORY POINTER
This is used to clear the address pointer to the Program
Memory. This ensures that the pointer is at a known
state as well as pointing to the first location in program
memory.
4.3.2 INCREMENT ADDRESS
This is used to increment the address pointer to the
Program Memory. This is used after the current location
has been programmed (or read).
FIGURE 4-1: RESET ADDRESS POINTER COMMAND (PROGRAM/VERIFY)
FIGURE 4-2: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
Command Value
RESET PROGRAM
MEMORY POINTER
0000 0000
LOAD DATA 0000 0010
READ DATA 0000 0100
INCREMENT ADDRSS 0000 0110
BEGIN PROGRAMMING 0000 1000
LOAD ADDRESS 0000 1010
READ ADDRESS 0000 1100
END PROGRAMMING 0000 1110
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12
00000000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS6
VIHH
PS3
PS4PS5
PS1
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12
01100000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS6
VIHH
PS3
PS4PS5
PS1
(NEXT COMMAND)
PIC17C7XX
DS30274B-page 3-80 2000 Microchip Technology Inc.
4.3.3 LOAD ADDRESS
This is used to load the address pointer to the Program
Memory with a specific 16-bit value. This is useful when
a specific range of locations are to be accessed.
4.3.4 READ ADDRESS
This is used so that the current address in the Program
Memory pointer can be determined. This can be used
to increase the robustness of the ISP programming
(ensure that the Program Memory pointers are still in
sync).
FIGURE 4-3: LOAD ADDRESS COMMAND
FIGURE 4-4: READ ADDRESS COMMAND
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
01010000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS7
VIHH
PS3
PS4PS5
PS1
PS6
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
00110000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS8
VIHH
PS3
PS4PS5
RA4 = Output
PS6
PS1
PS9
(NEXT COMMAND)
2000 Microchip Technology Inc. DS30274B-page 3-81
PIC17C7XX
4.3.5 LOAD DATA
This is used to load the 16-bit data that is to be pro-
grammed into the Program Memory location. The Pro-
gram Memory address may be modified after the data
is loaded. This data will not be programmed until a
BEGIN PROGRAMMING command is executed.
4.3.6 READ DATA
This is used to read the data in Program Memory that
is pointed to by the current address pointer. This is use-
ful for doing a verify of the programming cycle and can
be used to determine the number for programming
cycles that are required for the 3X overprogramming.
FIGURE 4-5: LOAD DATA COMMAND
FIGURE 4-6: READ DATA COMMAND
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
01000000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS7
VIHH
PS3
PS4PS5
PS1
SP6
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
00100000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS8
VIHH
PS3
PS4PS5
RA4 = Output
PS6
PS1
PS9
(NEXT COMMAND)
PIC17C7XX
DS30274B-page 3-82 2000 Microchip Technology Inc.
4.3.7 BEGIN PROGRAMMING
This is used to program the current 16-bit data (last
data sent with LOAD DATA Command) into the Pro-
gram Memory at the address specified by the current
address pointer. The programming cycle time is speci-
fied by specification P10. After this time has elapsed,
any command must be sent, which wakes the proces-
sor from the Long Write cycle. This command will be
the next executed command.
4.3.8 3X OVERPROGRAMMING
Once a location has been both programmed and veri-
fied over a range of voltages, 3X overprogramming
should be applied. In other words, apply three times the
number of programming pulses that were required to
program a location in memory, to ensure a solid pro-
gramming margin.
This means that every location will be programmed a
minimum of 4 times (1 + 3X overprogramming).
FIGURE 4-7: BEGIN PROGRAMMING COMMAND (PROGRAM)
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12
00010000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS10
VIHH
PS3
PS4PS5
PS1
(NEXT COMMAND)
78
2000 Microchip Technology Inc. DS30274B-page 3-83
PIC17C7XX
FIGURE 4-8: RECOMMENDED PROGRAMMING FLOWCHART
ISP Command
INCREMENT ADDRESS
or
LOAD ADDRESS
START
TEST = Vihh
MCLR = Vihh
N = 1
ISP Command
RESET ADDRESS
ISP Command
LOAD DATA
ISP Command
BEGIN PROGRAMMING
Wait approx 100 ms
ISP Command
READ DATA
Data Correct? N = N + 1
N > 25?
Report
Programming
Failure
ISP Command
BEGIN PROGRAMMING
Wait approx 100 ms
N = N - 1
N = 0?
Programmed all
required locations?
4.75V < VDD < 5.25V
Start Device Clock (on RA0),
TEST = MCLR = RA4 = RA5 = Vss
Ye s
No
Wait 80 Device Clocks
N = 3N
Verify all Locations
@ Vddmin
Data Correct?
Report
@ Vddmin
Verify all Locations
@ Vddmax
DONE
Data Correct? Verify
Error
Report
@ Vddmax
Ver ify
Error
No
Ye s
No
No
Ye s
Ye s
No
Ye s
Ye s
No
PIC17C7XX
DS30274B-page 3-84 2000 Microchip Technology Inc.
5.0 CONFIGURATION WORD
Configuration bits are mapped into program memory.
Each bit is assigned one memory location. In erased
condition, a bit will read as ‘1’. To program a bit, the
user needs to write to the memory address. The data is
immaterial; the very act of writing will program the bit.
The configuration word locations are shown in
Ta bl e 5-3 . The programmer should not program the
reserved locations to avoid unpredictable results
and to be compatible with future variations of the
PIC17C7XX. It is also mandatory that configuration
locations are programmed in the strict order start-
ing from the first location (0xFE00) and ending with
the last (0xFE0F). Unpredictable results may occur
if the sequence is violated.
5.1 Reading Configuration Word
The PIC17C7XX has seven configuration locations
(Table 5-1). These locations can be programmed (read
as ‘0’) or left unprogrammed (read as ‘1’) to select var-
ious device configurations. Any write to a configuration
location, regardless of the data, will program that con-
figuration bit. Reading any configuration location
between 0xFE00 and 0xFE07 will place the low byte of
the configuration word (Table 5-2) into DAD<7:0>
(PORTC). DAD<15:8> (PORTD) will be set to 0xFF.
Reading a configuration location between 0xFE08 and
0xFE0F will place the high byte of the configuration
word into DAD<7:0> (PORTC). DAD<15:8> (PORTD)
will be set to 0xFF.
TABLE 5-1: CONFIGURATION BIT
PROGRAMMING LOCATIONS
TABLE 5-2: READ MAPPING OF CONFIGURATION BITS
Bit Address
FOSC0 0xFE00
FOSC1 0xFE01
WDTPS0 0xFE02
WDTPS1 0xFE03
PM0 0xFE04
PM1 0xFE06
BODEN 0xFE0E
PM2 0xFE0F
—=Unused
PM<2:0>, Processor Mode Select bits
111 = Microprocessor mode
110 = Microcontroller mode
101 = Extended Microcontroller mode
000 = Code protected microcontroller mode
BODEN, Brown-out Detect Enable
1 = Brown-out Detect Circuitry enabled
0 = Brown-out Detect Circuitry disabled
WDTPS1:WDTPS0, WDT Prescaler Select bits.
11 = WDT enabled, postscaler = 1
10 = WDT enabled, postscaler = 256
01 = WDT enabled, postscaler = 64
00 = WDT disabled, 16-bit overflow timer
FOSC1:FOSC0, Oscillator Select bits
11 = EC oscillator
10 = XT oscillator
01 = RC oscillator
00 = LF oscillator
WDTPS1 FOSC1 FOSC0
WDTPS0
PM0PM1 —
—
PM2
11
1
111
11
11
1
111
11 BODEN PM2 PM2
89101112131415 01234567
PM2 PM2PM2
89101112131415 01234567
PM2
2000 Microchip Technology Inc. DS30274B-page 3-85
PIC17C7XX
5.2 Embedding Configuration Word Information in the Hex File
5.3 Reading From and Writing To a Code
Protected Device
When a device is code-protected, writing to program
memory is disabled. If program memory is read, the
value returned is the XNOR8 result of the actual pro-
gram memory word. The XNOR8 result is the upper
eight bits of the program memory word XNOR’d with
the lower eight bits of the same word. This 8-bit result
is then duplicated into both the upper and lower 8-bits
of the read value. The configuration word can always
be read and written.
To allow portability of code, a PIC17C7XX programmer is required to read the configuration word locations from the
hex file when loading the hex file. If the configuration word information was not present in the hex file, then a simple
warning message may be issued. Similarly, while saving a hex file, all configuration word information must be included.
An option to not include the configuration word information may be provided. When embedding configuration word
information in the hex file, it should be to address FE00h.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
PIC17C7XX
DS30274B-page 3-86 2000 Microchip Technology Inc.
5.4 CHECKSUM COMPUTATION
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
Table describes how to calculate the checksum for
each device. Note that the checksum calculation differs
depending on the code protect setting. Since the pro-
gram memory locations read out differently, depending
on the code protect setting, the table describes how to
manipulate the actual program memory values to sim-
ulate the values that would be read from a protected
device. When calculating a checksum by reading a
device, the entire program memory can simply be read
and summed. The configuration word and ID locations
can always be read.
Note: Some older devices have an additional
value added in the checksum. This is to
maintain compatibility with older device
programmer checksums.
TABLE 5-3: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank
Value
0xC0DE at 0
and max
address
PIC17C752 MP mode
MC mode
EMC mode
PMC mode
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM_XNOR8[0x0000:0x1FFF] + (CONFIG & 0xC05F)
0xA05F
0xA04F
0xA01F
0x200F
0x221D
0x220D
0x21DD
0xE3D3
PIC17C756 MP mode
MC mode
EMC mode
PMC mode
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM_XNOR8[0x0000:0x3FFF] + (CONFIG & 0xC05F)
0x805F
0x804F
0x801F
0x000F
0x021D
0x020D
0x01DD
0xC3D3
PIC17C756A MP mode
MC mode
EMC mode
PMC mode
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM_XNOR8[0x0000:0x3FFF] + (CONFIG & 0xC05F)
0x805F
0x804F
0x801F
0x000F
0x021D
0x020D
0x01DD
0xC3D3
PIC17C762 MP mode
MC mode
EMC mode
PMC mode
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x1FFF] + (CONFIG & 0xC05F)
SUM_XNOR8[0x0000:0x1FFF] + (CONFIG & 0xC05F)
0xA05F
0xA04F
0xA01F
0x200F
0x221D
0x220D
0x21DD
0xE3D3
PIC17C766 MP mode
MC mode
EMC mode
PMC mode
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM[0x0000:0x3FFF] + (CONFIG & 0xC05F)
SUM_XNOR8[0x0000:0x3FFF] + (CONFIG & 0xC05F)
0x805F
0x804F
0x801F
0x000F
0x021D
0x020D
0x01DD
0xC3D3
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a to b inclusive]
SUM_XNOR8(a:b) = [Sum of 8-bit wide XNOR copied into upper and lower byte, of locations a to b inclusive]
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
2000 Microchip Technology Inc. DS30274B-page 3-87
PIC17C7XX
5.5 Device ID Register
Program memory location FDFFh is preprogrammed
during the fabrication process with information on the
device and revision information. These bits are
accessed by a TABLR0 instruction, and are access
when the TEST pin is high. As as a result, the device ID
bits can be read when the part is code protected.
TABLE 5-4: DEVICE ID REGISTER DECODE
Resultant Device
Device
Device ID Value
DEV REV
PIC17C766 0000 0001 001 X XXXX
PIC17C762 0000 0001 101 X XXXX
PIC17C756 0000 0000 001 X XXXX
PIC17C756A 0000 0010 001 X XXXX
PIC17C752 0000 0010 101 X XXXX
PIC17C7XX
DS30274B-page 3-88 2000 Microchip Technology Inc.
6.0 PARALLEL MODE AC/DC CHARACTERISTICS AND TIMING
REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +70°C, unless otherwise stated, (25°C is recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.25V, unless otherwise stated.
Parameter
No. Sym. Characteristic Min. Typ. Max. Units Conditions/Comments
PD1 VDDP Supply voltage during pro-
gramming
4.75 5.0 5.25 V
PD2 IDDP Supply current during pro-
gramming
—— 50 mA Freq = 10MHz, VDD = 5.5V
PD3 VDDV Supply voltage during verify VDD
min.
—VDD
max.
V Note 2
PD4 VPP Voltage on VPP/MCLR pin
during programming
12.75 —13.25 V Note 1
PD6 IPP Programming current on
VPP/MCLR pin
—25 50 mA
P1 FOSCP Osc/clockin frequency dur-
ing programming
4—10 MHz
P2 TCY Instruction cycle 1 —0.4 µsTCY = 4/FOSCP
P3 TIRV2TSH RA0, RA1, RA2, RA3, RA4
setup before TEST↑
1——µs
P4 TTSH2MCH TEST↑ to MCLR↑1——µs
P5 TBCV2IRH RC7:RC0, RB7:RB0 valid to
RA1 or RA0↑:Address/Data
input setup time
0——µs
P6 TIRH2BCL RA1 or RA0↑ to RB7:RB0,
RC7:RC0 invalid; Address
data hold time;
10 TCY ——µs
P7 T0CKIL2RBCZRT↓ to RB7:RB0, RC7:RC0
hi-impedance
——8TCY
P8 T0CKIH2BCVRA1↑ to data out valid ——10 TCY
P9 TPROG Programming pulse width 100 1000 µs
P10 TIRH2IRL RA0, RA1 high pulse width 10 TCY ——µs
P11 TIRL2IRH RA0, RA1 low pulse width 10 TCY ——µs
P12 T0CKIV2INLRA1↑ before INT↓ (to go
from prog cycle to verify w/o
increment)
0——µs
P13 TINL2RTL RA1 valid after RA0 (to
select increment or no
increment going from pro-
gram to verify cycle
10 TCY ——µs
P14 TVPPS VPP setup time before RA0↑100 ——µs Note 1
P15 TVPPH VPP hold time after INT↓ 0 ——µs Note 1
P16 TVDV2TSHVDD stable to TEST↑10 ——ms
P17 T
RBV2MCH RB input (E1h) valid to VPP/
MCLR↑
0 ——µs
P18 TMCH2RBI RB input (E1h) hold after
VPP/MCLR↑
10TCY ——ns
P19 TVPL2VDLVDD power down after VPP
power down
10 ——ms
Note 1: VPP/MCLR pin must only be equal to or greater than VDD at times other than programming.
2: Program must be verified at the minimum and maximum VDD limits for the part.
2000 Microchip Technology Inc. DS30274B-page 3-89
PIC17C7XX
FIGURE 6-1: PARALLEL MODE PROGRAMMING AND VERIFY TIMINGS I
Tes t
MCLR
RA1
RA0
RB<7:0>
RC<7:0>
P4
P5
P18
INC
ADDR
E1H ADDR_HI DATA_HI OUT DATA_HI OUT DDATA_HI OUT
ADDR_LO DATA_LO OUT DATA_LO OUT DATA_LO OUT DATA_LO OUT
DATA_HI OUT
13V
5V
P14
P9
P15
P10 P11
P9
P7
P5
P6
Jump Address
Input
Programming
Mode Entry Load Address X
Verify location X
Increment Address to X + 1
by pulsing RA1
Verify location X + 1
Program location X + !
Do not increment PC
by raising RA1 before
RA0
Verify location X + 1
Note: RA2 = 0
RA3 = 0
RA4 = 1
PIC17C7XX
DS30274B-page 3-90 2000 Microchip Technology Inc.
FIGURE 6-2: PARALLEL MODE PROGRAMMING AND VERIFY TIMINGS II
Tes t
13V
5V
V
PP
/MCLR
RA1
RA0
RB<7:0>
RC<7:0>
E1H ADDR_HI DATA_HI OUT DATA_HI_IN DATA_HI_IN DATA_HI_IN DATA_HI OUT
ADDR_LO DATA_LO OUT
DATA_LO OUT DATA_LO_IN DATA_LO_IN DATA_LO_IN
P15
P9P9P9
Jump Address
Input
Programming
mode entry Load address X Verify location X Program location X
Program location X
Move to verify cycle
Prevent increment of
PC by raising RA1
before RA0
Verify location X
Note: RA2 = 0
RA3 = 0
RA4 = 1
P14
2000 Microchip Technology Inc. DS30274B-page 3-91
PIC17C7XX
FIGURE 6-3: PARALLEL MODE PROGRAMMING AND VERIFY TIMINGS III
P13
P13
P12
DATA_HIOUT
DATA_HI IN DATA_HI OUT DATA_HI IN DATA_HI OUT DATA_HI IN
DATA_LO OUT
DATA_LO IN DATA_LO OUT DATA_LO IN DATA_LO OUT DATA_LO IN
Verify location X
Program location X
Do not increment
PC Raise RA1 before
RA0 to do this
Verify location X
Program location X
Raise RA1 after RA0
to increment location X + 1
Verify location X + 1
Pulse RA1 to increment
address to X + 2
Verify location X + 2
RA1
RA0
RB<7:0>
RC<7:0>
INC PC
Note: Device in PGM mode
Te s t = + 6
V
PP
/MCLR = V
PP
RA2 = 0
RA3 = 0
RA4 = 1
INC PC
INC PC
PIC17C7XX
DS30274B-page 3-92 2000 Microchip Technology Inc.
FIGURE 6-4: POWER-UP/DOWN SEQUENCE FOR PROGRAMMING
P16
P19
P3
P17
P18
E1H
VDD
VPP/MCLR
Te s t
RA4
RA2
RA3
RA0
RB<7:0>
2000 Microchip Technology Inc. DS30274B-page 3-93
PIC17C7XX
7.0 ELECTRICAL SPECIFICATIONS FOR SERIAL PROGRAMMING MODE
All parameters apply across the specified operating ranges
unless otherwise noted.
Vcc = 2.5V to 5.5V
Commercial (C): Tamb = 0° to +70°C
Industrial (I): Tamb = -40°C to +85°C
Parameter
No.
Sym Characteristic Min Typ† Max Units Conditions
VIHH Programming Voltage on VPP/
MCLR pin and TEST pin.
12.75 —13.75 V
IPP Programming current on MCLR pin —25 50 mA
FOSC Input OSC frequency on RA1 —— 8MHz
TCY Instruction Cycle Time —4/FOSC —
PS1 TVH2VH Setup time between TEST = VIHH
and MCLR = VIHH
1——µs
PS2 TSER Serial setup time 20 ——TCY
PS3 TSCLK Serial Clock period 1 ——TCY
PS4 TSET1 Input Data Setup Time to serial
clock ↓
15 ——ns
PS5 THLD1 Input Data Hold Time from serial
clock ↓
15 ——ns
PS6 TDLY1 Delay between last clock ↓ to first
clock ↑ of next command
20 ——TCY
PS7 TDLY2 Delay between last clock ↓ of com-
mand byte to first clock ↑ of read of
data word
20 ——TCY
PS8 TDLY3 Delay between last clock ↓ of com-
mand byte to first clock ↑ of write of
data word
30 ——TCY
PS9 TDLY4 Data input not driven to next clock
input
1——TCY
PS10 TDLY5 Delay between last begin program-
ming clock ↓ to last clock ↓ of next
command (minimum programming
time)
100 ——µs
* These parameters are characterized but not tested.
† Data in “Ty p ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not
tested.
PIC17C7XX
DS30274B-page 3-94 2000 Microchip Technology Inc.
FIGURE 7-1: RESET ADDRESS POINTER COMMAND (PROGRAM/VERIFY)
FIGURE 7-2: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12
00000000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS6
VIHH
PS3
PS4PS5
PS1
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12
01100000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS6
VIHH
PS3
PS4PS5
PS1
(NEXT COMMAND)
2000 Microchip Technology Inc. DS30274B-page 3-95
PIC17C7XX
FIGURE 7-3: LOAD ADDRESS COMMAND
FIGURE 7-4: READ ADDRESS COMMAND
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
01010000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS7
VIHH
PS3
PS4PS5
PS1
PS6
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
00110000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS8
VIHH
PS3
PS4PS5
RA4 = Output
PS6
PS1
PS9
(NEXT COMMAND)
PIC17C7XX
DS30274B-page 3-96 2000 Microchip Technology Inc.
FIGURE 7-5: LOAD DATA COMMAND
FIGURE 7-6: READ DATA COMMAND
FIGURE 7-7: BEGIN PROGRAMMING COMMAND (PROGRAM)
MCLR/VPP
VIHH
RA1/T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
01000000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS7
VIHH
PS3
PS4PS5
PS1
PS6
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1T0CKI
Te s t
RA5 (Clock)
RA4 (Data)
12345678 12 31516 1
00100000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS8
VIHH
PS3
PS4PS5
RA4 = Output
PS6
PS1
PS9
(NEXT COMMAND)
MCLR/VPP
VIHH
RA1/T0CKI
Test
RA5 (Clock)
RA4 (Data)
12345678 12
00010000
PS2
Reset
RA4 = Input
Program/Verify Test Mode
PS10
VIHH
PS3
PS4PS
PS1
(NEXT COMMAND)
78
2000 Microchip Technology Inc. DS39028A-page 3-97
PIC18CXXX
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC18CXXX
The PIC18CXXX can be programmed using a serial
method. while in the users system. This allows for
increased design flexibility. This programming specifi-
cation applies to PIC18CXXX devices in all package
types.
1.1 Hardware Requirements
The PIC18CXXX requires two programmable power
supplies, one for VDD (2.0V to 5.5V recommended) and
one for VPP (12V to 14V). Both supplies should have a
minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC18CXXX allows
programming of user program memory, special loca-
tions used for ID, and the configuration word for the
PIC18CXXX.
Pin Diagram
• PIC18C452
• PIC18C252
• PIC18C242
• PIC18C442
PIC18C2XX
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RD7
RD6
RD5
RD4
RC7
RC6
RC5
RC4
RD3
RD2
MCLR/VPP
RA0
RA1
RA2
RA3
RA4/T0CKI
RA5
RE0
RE1
RE2
VDD
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0
RC1
RC2
RC3
RD0
RD1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
PDIP, Windowed CERDIP
PDIP, SOIC, Windowed CERDIP (300 mil)
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RC7
RC6
RC5
RC4
• 1
2
3
4
5
6
7
8
9
10
11
12
13
14
MCLR/VPP
RA0
RA1
RA2
RA3
RA4/T0CKI
RA5
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0
RC1
RC2
RC3
PIC18C4XX
TABLE 1-1: PIN DESCRIPTIONS (DURING PROGRAMMING): PIC18C242/252/442/452
Pin Name
During Programming
Pin Name Pin Type Pin Description
MCLR/VPP VPP P Programming Power
VDD VDD P Power Supply
Vss VSS P Ground
RB6 RB6 I Serial Clock
RB7 RB7 I/O Serial Data
Legend: I = Input, O = Output, P = Power
In-Circuit Serial Programming for PIC18CXXX OTP MCUs
PIC18CXXX
DS39028A-page 3-98 2000 Microchip Technology Inc.
2.0 IN-CIRCUIT SERIAL
PROGRAMMING MODE (ICSP)
2.1 Introduction
Serial programming mode is entered by asserting
MCLR/VPP = VIHH and RB6, RB7 = 0.
Instructions are fed into the CPU serially on RB7, and
are shifted in on the rising edge of the serial clock pre-
sented on RB6. Programming and verification are per-
formed by executing TBLRD and TBLWT instructions.
The address pointer to the program memory is simply
the table pointer. The address pointer can be incre-
mented and decremented by executing table reads and
writes with auto-decrement and auto-increment.
2.2 ICSP OPERATION
In ICSP mode, instruction execution takes place
through a serial interface using RB6 and RB7. RB7 is
used to shift in instructions and shift out data from the
TABLAT register. RB6 is used as the serial shift clock
and the CPU execution clock. Instructions and data
are shifted in LSb first.
In this mode all instructions are shifted serially, then
loaded into the instruction register, and executed. No
program fetching occurs from internal or external pro-
gram memory. 8-bit data bytes are read from the
TABLAT register via the same serial interface.
2.2.1 4-BIT SERIAL INSTRUCTIONS
A set of 4-bit instructions are provided for ICSP mode,
so that the most common instructions used for ICSP
can be fetched quickly, and thus reduce the amount of
time required to program a device. The 4-bit opcode is
shifted in while the previous instruction fetched exe-
cutes. The 4-bit instruction contains the lower 4-bits of
an instruction opcode. The upper 12-bits default as all
0’s. Instructions with all 0’s in the upper byte of the
instruction word, are by default considered special
instructions. The serial instructions are decoded as
shown in Table 2-1:
TABLE 2-1: SPECIAL INSTRUCTIONS FOR SERIAL INSTRUCTION EXECUTION AND ICSP
Mnemonic,
Operands Description Cycles 4-Bit Opcode Status
Affected
NOP No Operation (Shift in16-bit instruction) 1 0000 None
TBLRD * Table Read (no change to TBLPTR) 2 1000 None
TBLRD *+ Table Read (post-increment TBLPTR) 2 1001 None
TBLRD *- Table Read (post-decrement TBLPTR) 2 1010 None
TBLRD +* Table Read (pre-increment TBLPTR) 2 1011 None
TBLWT * Table Write (no change to TBLPTR) 2 1100 None
TBLWT *+ Table Write (post-increment TBLPTR) 2 1101 None
TBLWT *- Table Write (post-decrement TBLPTR) 2 1110 None
TBLWT +* Table Write (pre-increment TBLPTR) 2 1111 None
Legend: Refer to the PIC18CXXX Data Sheet (DS39026) for opcode field descriptions.
Note: All special instructions not included in this table are decoded as NOP’s
In-Circuit Serial Programming™ (ICSP) is a trademark of Microchip Technology Inc.
2000 Microchip Technology Inc. DS39028A-page 3-99
PIC18CXXX
2.2.2 INITIAL SERIAL INSTRUCTION
OPERATION
Upon ICSP mode entry, the CPU is idle. The execution
of the CPU is governed by a state machine. The CPU
clock source comes from RB6 which also acts as the
serial shift clock. The first clock transition on RB6 is
absorbed after RESET. While the first instruction is
being clocked in, a forced NOP is executed.
Following the FNOP instruction execution and the next
shifting in of the next instruction, the serial state
machine will do one of three things depending upon
the 4-bit instruction that was fetched:
1. If the instruction fetched was a NOP, the state
machine will suspend the CPU awaiting a 16-bit
wide instruction to be shifted in.
2. If the instruction is a TBLWT, the state machine
suspends the CPU from execution while sixteen
bits of data are shifted in as data for the TBLWT
instruction.
3. If the instruction is a TBLRD, then execution of
the TBLRD instruction begins immediately for
eight clock cycles, followed by eight clock cycles
where the contents of the TABLAT register is
shifted out onto RB7.
Once sixteen clock cycles have elapsed, the next 4-bit
instruction is fetched while the current instruction is
executed. Each instruction type is described in later
sections.
FIGURE 2-1: SERIAL INSTRUCTION TIMING AFTER RESET
Q1
Q Cycles
P2
Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB7 = Input or Output depending upon instruction
ICSP Mode
16-bit Instruction Load or Execute Instruction,
Execute FNOP
Fetch 4-bit Instruction Fetch Next 4-bit
Q4Q1
MCLR/VPP
VIHH
P1
Reset
16-bit data Fetch or
Perform TABLRD followed by shift data out Instruction
1234 12 1516 1234
RB6 (Clock)
P5 P5
34 65 7 8 9 10 12 13 1411
P4P3
P9
RB7 (Data) 1101
1101
(TBLWT **)
PIC18CXXX
DS39028A-page 3-100 2000 Microchip Technology Inc.
2.2.3 NOP SERIAL INSTRUCTION EXECUTION
The NOP serial instruction is used to allow execution of
all other instructions not included in Table 2-1. When
the NOP instruction is fetched, the serial execution
state machine suspends the CPU for 16 clock cycles.
During these 16 clock cycles, all 16-bits of an instruc-
tion are fed into the CPU and the NOP instruction is
discarded. Once all 16 bits have been shifted in the
state machine will allow the instruction to be executed
for the next 4 clock cycles.
2.2.4 ONE CYCLE 16-BIT INSTRUCTIONS
If the instruction fetched is a one cycle instruction,
then the instruction operation will be completed in the
4 clock cycles following the instruction fetched. During
instruction execution, the next 4-bit serial instruction is
fetched (See Figure 2-2).
FIGURE 2-2: SERIAL INSTRUCTION TIMING FOR 1 CYCLE 16-BIT INSTRUCTIONS
Note: 16-bit TBLWT and TBLRD instructions are
not permitted. They will cause timing prob-
lems with the serial state machine. If the
user wishes to perform a TBLWT or TBLRD
instruction, it must be performed as a 4-bit
instruction.
MCLR/VPP = VIHH
P5
P3P4
Q1
Q Cycles
23 123 1516 1234
P2
RB6 (Clock)
P5
Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB7 = Input
ICSP Mode
16-bit Instruction Fetch Execute 16-bit Instruction,
Execute PC-2,
14
Fetch NOP to enable
16-bit Instruction fetch
Fetch Next Serial
4 5 6 7 8 9 10 11 12 13 14
Q4
4-bit Instruction
RB7 (Data) 1101
0000
2000 Microchip Technology Inc. DS39028A-page 3-101
PIC18CXXX
FIGURE 2-3: 16-BIT 1 CYCLE SERIAL INSTRUCTION FLOW AFTER RESET
Start
Num_Clk = 1,
Clock
Transition
RB6?
Yes
No
MCLR = VIHH
MCLR = VSS,
RB6, RB7 = 0 Num_Clk = 1,
Execute 16-bit Instruction,
Clock
Transition
RB6?
Yes
No
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
Num_Clk = 16?
Clock
Transition
RB6?
Yes
Yes
No
No
Shift in 1st
4-bit instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
and shift in next
4-bit instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
4-bit instruction = NOP,
Shift in 16-bit instruction,
Num_Clk = 1
PIC18CXXX
DS39028A-page 3-102 2000 Microchip Technology Inc.
FIGURE 2-4: 16-BIT 1 CYCLE SERIAL INSTRUCTION FLOW
Start
Num_Clk = 1,
Clock
Transition
RB6?
Yes
No
execute (PC - 2),
Num_Clk = 1,
execute 16-bit Instruction,
Clock
Transition
RB6?
Yes
No
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
Num_Clk = 16?
Clock
Transition
RB6?
Yes
Yes
No
No
and shift in next
4-bit instruction,
Shift(R) RB7
into ROMLAT<15>,
Num_Clk = Num_Clk + 1
and shift in next
4-bit instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
4-bit instruction = NOP,
Shift in 16-bit instruction,
Num_Clk = 1
2000 Microchip Technology Inc. DS39028A-page 3-103
PIC18CXXX
2.3 Serial Instruction Execution For Two
Cycle, One Word Instructions
When a NOP instruction is fetched, the serial execution
state machine suspends the CPU for 16 clock cycles.
During these 16 clock cycles, all 16-bits of an instruc-
tion are fed in and the NOP instruction is discarded.
If the instruction fetched is a two cycle, one word
instruction, then the instruction operation will require a
second “dummy fetch” to be performed before the
instruction execution can be completed. The first cycle
of the instruction will be executed in the 4 clock cycles
following the instruction fetched. During the first cycle
of instruction execution, the next 4-bit serial instruction
is fetched. In order to perform the second half of the
two cycle instruction, this 4-bit instruction loaded in
must be a NOP, so that state machine will remain idle
for the second half of the instruction. Following the
fetch of the second NOP, the state machine will shift
16-bits of data that will be discarded. After the 16-bits
of data is shifted in, the state machine will release the
CPU, and allow it to perform the second half of the two
cycle instruction. During the second half of the two
cycle instruction execution, the next 4-bit instruction is
loaded (See Figure 2-5).
FIGURE 2-5: 2 CYCLE 1 WORD 16-BIT INSTRUCTION SEQUENCE
Q Cycles
12 3 4 121516
P5 P5
1234
Q1 Q2 Q3 Q4
MCLR/VPP
RB7 = Input
ICSP Mode
P3P4
Execute PC-2 Fetch 16-bit Instruction
P2
RB6 (Clock)
Q1 Q2 Q3 Q4
Fetch 2nd 16-bit
Execute 1st Cycle
P5
121516
P5
1234
Q1 Q2 Q3 Q4
Fetch 4-bit NOP
Execute 2nd Cycle,Fetch 4-bit NOP,
Fetch Next 4-bit Instruction
Operand Word (discarded)
of 16-bit Instruction
RB7 (Data) 1101
0000
PIC18CXXX
DS39028A-page 3-104 2000 Microchip Technology Inc.
2.4 Serial Instruction Execution For Two
Word, Two Cycle Instructions
After a NOP instruction is fetched, the serial execution
state machine suspends the CPU in the Q4 state for
16 clock cycles. During these 16 clock cycles, all 16-
bits of an instruction are fed in and the NOP instruction
is discarded.
If the 16-bit instruction fetched is a two cycle, two word
instruction, then the instruction operation will require a
second operand fetch to be performed before the
instruction execution can be completed. The first cycle
of the instruction will be executed in the 4 clock cycles
following the 16-bit instruction fetch. During the first
cycle of instruction execution, the next 4-bit serial
instruction is fetched. In order to perform the second
half of the two cycle instruction, this 4-bit instruction
loaded in must also be a NOP, so that the state
machine will remain idle for the second half of the
instruction. Following the fetch of the second NOP, the
state machine will shift 16-bits of data that will be used
as an operand for the two cycle instruction. After the
16-bits of data are shifted in, the state machine will
release the CPU, and allow it to execute the second
half of the two cycle instruction. During the second half
of the two cycle instruction execution, the next 4-bit
instruction is loaded (see Figure 2-6).
FIGURE 2-6: 16-BIT 2 CYCLE 2 WORD INSTRUCTION SEQUENCE
MCLR/VPP = VIHH
P5
P3P4
Q1
Q Cycles
23 12315 16 1 2 3 4 1 2 15 16 1 2 3 4
P2
RB6 (Clock)
P5 P5 P5
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB7 = Input
ICSP Mode
Execute 1st Cycle,
Execute PC-2, Execute 2nd Cycle,
14
Fetch 2nd word
Fetch 1st word
Fetch next 4-bit
Fetch 4-bit NOP Fetch 4-bit NOP
Instruction
RB7 (Data) 1101
0000 0000
2000 Microchip Technology Inc. DS39028A-page 3-105
PIC18CXXX
FIGURE 2-7: 16-BIT 2 CYCLE 2 WORD SERIAL INSTRUCTION FLOW AFTER RESET
Start
MCLR = VPP,
RB6, RB7 = 0
Num_Clk = 1,
4-bit instruction = NOP,
Num_Clk = 1
Num_Clk = 16?
Clock
Transition
RB6?
Clock
Transition
RB6?
Yes
No
Yes
Yes
No
No
execute FNOP and shift in
Shift in 16-bit instruction,
Num_Clk = 1
Num_Clk = 16?
Clock
Transition
RB6?
Yes
Yes
No
No
Enable CPU,
Num_Clk = 1,
execute 1st cycle of 16-bit
Clock
Transition
RB6?
Yes
No
execute 2nd cycle of 16-bit
End
MCLR = VIHH
Shift in 2nd 16-bit operand,
Clock
Transition
RB6?
Yes
No
Shift(R) RB7,
Num_Clk = Num_Clk + 1
instruction, and shift in next
4-bit instruction,
4-bit instruction = NOP,
1st 4-bit instruction,
Shift(R) RB7,
Num_Clk = Num_Clk + 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
instruction, and shift in
next 4-bit instruction
Num_Clk = 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
PIC18CXXX
DS39028A-page 3-106 2000 Microchip Technology Inc.
FIGURE 2-8: 16-BIT 2 CYCLE 2 WORD SERIAL INSTRUCTION FLOW
Start
Num_Clk = 1,
Num_Clk = 16?
Clock
Transition
RB6?
Clock
Transition
RB6?
Yes
No
Yes
Yes
No
No
execute (PC-2)and shift in
Shift in 16-bit instruction,
Num_Clk = 1
Num_Clk = 16?
Clock
Transition
RB6?
Yes
Yes
No
No
Num_Clk = 1,
execute 1st cycle of 16-bit
Clock
Transition
RB6?
Yes
No
execute 2nd cycle of 16-bit
End
Clock
Transition
RB6?
Yes
No
Shift(R) RB7,
Num_Clk = Num_Clk + 1
instruction, and shift in next
4-bit instruction,
4-bit instruction = NOP,
4-bit instruction,
Shift(R) RB7,
Num_Clk = Num_Clk + 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
instruction, and shift in
next 4-bit instruction
Num_Clk = 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
Shift(R) RB7,
Num_Clk = Num_Clk + 1
4-bit instruction = NOP,
Num_Clk = 1
Shift in 2nd 16-bit operand,
2000 Microchip Technology Inc. DS39028A-page 3-107
PIC18CXXX
2.5 TBLWT Instruction
The TBLWT instruction is a unique two cycle instruc-
tion.
All forms of TBLWT instructions (post/pre-increment,
post decrement, etc.) are encoded as 4-bit special
instructions. This is useful as TBLWT instructions are
used repeatedly in ICSP mode. A 4-bit instruction will
minimize the total number of clock cycles required to
perform programming algorithms.
The TBLWT instruction sequence operates as follows:
1. The 4-bit TBLWT instruction is read in by the
state machine on RB7 during the 4 clock cycle
execution of the instruction fetched previous to
the TBLWT (which is an FNOP if the TBLWT is
executed following a reset).
2. Once the state machine recognizes that the
instruction fetched is a TBLWT, the state
machine proceeds to fetch in the 16-bits of data
that will be written into the program memory
location pointed to by the TBLPTR.
3. The serial state machine releases the CPU to
execute the first cycle of the TBLWT instruction
while the first 4 bits of the 16-bit data word are
shifted in. After the first cycle of TBLWT instruc-
tion has completed the state machine shifts in
the remaining 12 of the sixteen bits of data. The
data word will not be used until the second cycle
of the instruction.
4. After all 16-bits of data are shifted in and the first
cycle of the TBLWT is performed, the CPU is
allowed to execute the second cycle of the
TBLWT operation, programming the current
memory location with the 16-bit value. The next
instruction following the TBLWT instruction is
shifted in during the execution of the second
cycle (See Figure 2-9).
The TBLWT instruction is used in ICSP mode to pro-
gram the EPROM array. When writing a 16-bit value
to the EPROM, ID locations, or configuration locations,
the device, RB6, must be held high for the appropriate
programming time during the TBLWT instruction as
specified by parameter P9.
When RB6 is asserted low the device will cease pro-
gramming the specified location.
After RB6 is asserted low, RB6 is held low for the time
specified by parameter P10, to allow high voltage dis-
charge of the program memory array.
FIGURE 2-9: TBLWT INSTRUCTION SEQUENCE
MCLR/VPP = VIHH
Q Cycles
1 2 3 4 1 2 15 16 1 2 3 4
RB6 (Clock)
P5 P5
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB7 = Input
ICSP Mode
Execute PC-2 Execute 2nd Cycle TBLWT
Load TBLWT Data
Fetch TBLWT
34 65 7 8910 12131411
Execute 1st
Cycle TBLWT
P2
P4P3
P9
and fetch next 4-bit
Q1 Q2 Q3 Q4
instruction
P10
RB7 (Data) 1101
00 0000
11
PIC18CXXX
DS39028A-page 3-108 2000 Microchip Technology Inc.
FIGURE 2-10: TBLWT SERIAL INSTRUCTION FLOW AFTER RESET
Start
Num_Clk = 1,
4-bit instruction = TBLWT,
Begin Shifting in TBLWT data,
Num_Clk = 1
Clock
Transition
RB6?
Yes
No
Execute FNOP,
MCLR = VIHH
MCLR = VSS,
RB6, RB7 = 0
Num_Clk = 1,
Num_Clk = 12?
Clock
Transition
RB6?
Yes
Yes
No
No
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
Execute 1st cycle of TBLWT,
Num_Clk = 4?
Clock
Transition
RB6?
Yes
Yes
No
No
and shift in 4-bit
TBLWT instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
shift in last 12 bits
of TBLWT data,
Shift(R) RB7
Num_Clk = Num_Clk + 1
Num_Clk = 1,
Execute 2nd cycle of TBLWT
Clock
Transition
RB6?
Yes
No
instruction and shift in next
4-bit instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
2000 Microchip Technology Inc. DS39028A-page 3-109
PIC18CXXX
FIGURE 2-11: TBLWT SERIAL INSTRUCTION FLOW
Start
Num_Clk = 1,
4-bit instruction = TBLWT,
Begin Shifting in TBLWT data,
Num_Clk = 1
Clock
Transition
RB6?
Yes
No
Execute (PC-2),
Num_Clk = 1,
Num_Clk = 12?
Clock
Transition
RB6?
Yes
Yes
No
No
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
Execute 1st cycle of TBLWT,
Num_Clk = 4?
Clock
Transition
RB6?
Yes
Yes
No
No
and shift in 4-bit
TBLWT instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
Shift in last 12 bits
of TBLWT data,
Shift(R) RB7
Num_Clk = Num_Clk + 1
Num_Clk = 1,
Execute 2nd cycle of TBLWT
Clock
Transition
RB6?
Yes
No
instruction and shift in next
4-bit instruction,
Shift(R) RB7
Num_Clk = Num_Clk + 1
PIC18CXXX
DS39028A-page 3-110 2000 Microchip Technology Inc.
2.6 TBLRD Instruction
The TBLRD instruction is another unique two cycle
instruction.
All forms of TBLRD instructions (post/pre-increment,
post decrement, etc.) are encoded as 4-bit special
instructions. This is useful as TBLRD instructions are
used repeatedly in ICSP mode. A 4-bit instruction will
minimize the total number of clock cycles required to
perform programming algorithms.
The TBLRD instruction sequence operates as follows:
1. The 4-bit TBLRD instruction is read in by the
state machine on RB7 during the 4 clock cycle
execution of the instruction fetched previous to
the TBLRD (which is an FNOP if the TBLRD is
executed following a reset).
2. Once the state machine recognizes that the
instruction fetched is a TBLRD, the state
machine releases the CPU and allows execu-
tion of the first and second cycles of the TBLRD
instruction for eight clock cycles. When the
TBLRD is performed, the contents of the pro-
gram memory byte pointed to by the TBLPTR is
loaded into the TABLAT register.
3. After eight clock cycles have transitioned on
RB6, and the TBLRD instruction has completed,
the state machine will suspend the CPU for eight
clock cycles. During these eight clock cycles,
the state machine configures RB7 as an output,
and will shift out the contents of the TABLAT reg-
ister onto RB7 LSb first.
4. When the state machine has shifted out all eight
bits of data, the state machine suspends the
CPU to allow an instruction pre-fetch. Four (4)
clock cycles are required on RB6 to shift in the
next 4-bit instruction.
FIGURE 2-12: TBLRD INSTRUCTION SEQUENCE
MCLR/VPP = VIHH
Q Cycles
1234 1234
RB6 (Clock)
P5
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RB7 (Data)
RB7 = Input
ICSP Mode
Execute PC-2 Execute Cycle 2
Execute Cycle 1 Shift Data Out From TABLAT
P6
RB7 = Output
1234
Q1 Q2 Q3 Q4
1234
P5
Fetch TBLRD
123 5 7864
TBLRD TBLRD
No Execution takes place,
Fetch Next 4-bit instruction
10 0 1 10 0 1
RB7 = Input
LSb MSb123456
2000 Microchip Technology Inc. DS39028A-page 3-111
PIC18CXXX
FIGURE 2-13: TBLRD SERIAL INSTRUCTION FLOW AFTER RESET
Start
Num_Clk = 1,
Enable CPU,
cycle TBLRD instruction
Clock
Transition
RB6?
Yes
No
Execute FNOP,
MCLR = VIHH
MCLR = VSS,
RB6, RB7 = 0
Shift out 8-bits
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
execute 1st and 2nd
Num_Clk = 8?
Clock
Transition
RB6?
Yes
Yes
No
No
and shift in 4-bit
TBLRD instruction,
TBLRD instruction execution
Num_Clk = Num_Clk + 1
of data to RB7
Num_Clk = 8?
Clock
Transition
RB6?
Yes
Yes
No
No
Shift(R) TABLAT<0>
out onto RB7
Num_Clk = Num_Clk + 1
4-bit instruction
Shift in next
Num_Clk = 4?
Clock
Transition
RB6?
Yes
Yes
No
No
Shift(R) RB7
Num_Clk = Num_Clk + 1
takes place here
PIC18CXXX
DS39028A-page 3-112 2000 Microchip Technology Inc.
FIGURE 2-14: TBLRD SERIAL INSTRUCTION FLOW
Start
Num_Clk = 1,
cycle TBLRD instruction
Clock
Transition
RB6?
Yes
No
Execute (PC-2),
Shift out 8-bits
End
Shift(R) RB7
Num_Clk = Num_Clk + 1
Execute 1st and 2nd
Num_Clk = 8?
Clock
Transition
RB6?
Yes
Yes
No
No
and shift in 4-bit
TBLRD instruction,
of data to RB7
Num_Clk = 8?
Clock
Transition
RB6?
Yes
Yes
No
No
4-bit instruction
Shift in next
Num_Clk = 4?
Clock
Transition
RB6?
Yes
Yes
No
No
Shift(R) RB7
Num_Clk = Num_Clk + 1
Shift(R) TABLAT<0>
out onto RB7
Num_Clk = Num_Clk + 1
TBLRD instruction execution
Num_Clk = Num_Clk + 1
takes place here
2000 Microchip Technology Inc. DS39028A-page 3-113
PIC18CXXX
2.6.1 SOFTWARE COMMANDS
ICSP commands of the PICmicro® MCU are supported
in the PIC18CXXX family by simply combining CPU
instructions. Once in In-Circuit Serial Programming
(ICSP) mode, the instructions are loaded into a shift
register, and the device waits for a command to be
received. The ICSP commands for the PIC16CXXX
family are now “pseudo-commands” and are shown in
Table 2-2. The following sections are a description of
how the pseudo-commands can be implemented using
CPU instructions.
TABLE 2-2: ICSP PSEUDO COMMAND MAPPING
ICSP Command Golden Gate Instructions
Load Configuration MOVLW
#Address1
MOVWF
TBLPTRL
MOVLW
#Address2
MOVWF
TBLPTRH
MOVLW
#Address3
MOVWF
TBLPTRU
Load Data Not needed. Data encoded in 4-bit TBLWT instruction sequence.
Read Data TBLRD instruction
Increment Address Not needed. Use TBLWT with increment/decrement (TBLWT *+/*-).
Load Address MOVLW
#Addr_low
MOVWF
TBLPTRL
MOVLW
#Addr_high
MOVWF
TBLPTRH
MOVLW
#Addr_upper
MOVWF
TBLPTRU
Reset Address MOVLW
#Data
MOVWF
TBLPTRH
MOVWF
TBLPTRL
MOVWF
TBLPTRU
Begin programming TBLWT
End Programming Not needed. Programming will cease at the end of TBLWT execution.
PIC18CXXX
DS39028A-page 3-114 2000 Microchip Technology Inc.
2.6.2 RESET ADDRESS
A reset of the program memory pointer is a write to the
upper, high, and low bytes of the TBLPTR. To reset the
program memory pointer, the following instruction
sequence is used.
NOP ;(4-BIT INSTRUCTION)
MOVLW 00h
NOP ;(4-BIT INSTRUCTION)
MOVWF TBLPTRU, 0
NOP ;(4-BIT INSTRUCTION)
MOVWF TBLPTRH, 0
NOP ;(4-BIT INSTRUCTION)
MOVWF TBLPTRL, 0
2000 Microchip Technology Inc. DS39028A-page 3-115
PIC18CXXX
FIGURE 2-15: RESET ADDRESS SERIAL INSTRUCTION SEQUENCE
Start
Num_Clk = 4?
Yes
No
execute (PC - 2),
End
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
Num_Clk = 16?
Yes
No
shift in next 4-bit instruction, Shift in 16-bit MOVWF instruction,
Num_Clk = 1
4-bit instruction = NOP,
Num_Clk = 1,
Num_Clk = 4?
Yes
No
Num_Clk = 16?
Yes
No
Num_Clk = 1,
Execute MOVLW Instruction,
shift in 4-bit NOP instruction,
Num_Clk = 1,
execute MOVWF Instruction,
shift in 4-bit NOP instruction,
On rising edge RB6
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift in 16-bit MOVWF instruction,
Num_Clk = 1
4-bit instruction = NOP,
Num_Clk = 16?
Yes
No
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Num_Clk = 1,
Execute MOVWF Instruction,
shift in next 4-bit instruction,
Num_Clk = 4?
Yes
No
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
On rising edge RB6
(NOP)
(NOP)
(NOP)
(NOP)
(NOP)
MOVLW 00h
MOVWF
TBLPTRM,0
MOVWF
TBLPTRM,0
(NOP)
4-bit instruction = NOP,
Num-Clk = 1
Shift in 16-bit MOVLW instruction,
PIC18CXXX
DS39028A-page 3-116 2000 Microchip Technology Inc.
2.6.3 LOAD ADDRESS
This is used to load the address pointer to the Program
Memory with a specific 22-bit value. This is useful when
a specific range of locations are to be accessed. To
load the address into the table pointer, the following
commands must be used:
NOP ; 4-bit instruction
MOVLW Low_Address
NOP ; 4-bit instruction
MOVWF TBLPTRL, 0
NOP ; 4-bit instruction
MOVLW High_Address
NOP ; 4-bit instruction
MOVWF TBLPTRH, 0
NOP ; 4-bit instruction
MOVLW Upper_Address
NOP ; 4-bit instruction
MOVWF TBLPTRU, 0
2000 Microchip Technology Inc. DS39028A-page 3-117
PIC18CXXX
FIGURE 2-16: LOAD ADDRESS SERIAL INSTRUCTION SEQUENCE
Start
Num_Clk = 4?
Shift in 16-bit MOVLW instruction,
Num_Clk = 1
Yes
No
execute (PC - 2),
End
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
4-bit instruction = NOP,
Num_Clk = 16?
Yes
No
shift in next 4-bit instruction, Shift in 16-bit MOVWF instruction,
Num_Clk = 1
4-bit instruction = NOP,
Num_Clk = 1,
Num_Clk = 4?
Yes
No
Num_Clk = 16?
Yes
No
Num_Clk = 1,
execute MOVLW Instruction,
shift in 4-bit NOP instruction,
Num_Clk = 1,
execute MOVWF Instruction,
shift in 4-bit NOP instruction,
On rising edge RB6
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Shift in 16-bit MOVWF instruction,
Num_Clk = 1
4-bit instruction = NOP,
Num_Clk = 16?
Yes
No
Shift(R) RB7
into Shift Reg<15>,
Num_Clk = Num_Clk + 1
On rising edge RB6
Num_Clk = 1,
execute MOVWF Instruction,
shift in next 4-bit instruction,
Num_Clk = 4?
Yes
No
Shift(R) RB7
into Shift Reg<3>,
Num_Clk = Num_Clk + 1
On rising edge RB6
(NOP)
(NOP)
MOVLW
LOW_Address
MOVWF
TBLPTRL,0
MOVLW
HIGH_Address
(NOP)
PIC18CXXX
DS39028A-page 3-118 2000 Microchip Technology Inc.
2.6.4 ICSP BEGIN PROGRAMMING
Programming is performed by executing a TBLWT
instruction. In ICSP mode the TBLWT instruction
sequence will include 16-bits of data that are shifted
into a data buffer, and then written to the word location
that is addressed by the TBLPTR. Although the
TBLPTR addresses the program memory on a byte
wide boundary, all 16-bits of data that are shifted in dur-
ing the TBLWT sequence are written at once. The
16-bits are shifted into the TABLAT and buffer registers.
The TBLPTR points to the word that will be pro-
grammed; it can point to either the high or the low byte.
(See Figure 2-17).
The sequence for programming a location could occur
as follows:
1. Setup the TLBPTR with the first ok address to
be programmed (even or odd byte).
2. Shift in a 4 bit TBLWT instruction.
3. 16-bits of data are then shifted in for program-
ming both high and low byte of the first pro-
grammed location.
4. Execute TBLWT instruction to program location.
5. Verify high byte (odd address) by executing
TLBRD *- (post-decrement). (If TBLPTR point-
ing at odd address.)
6. Verify low byte (even address) by executing
TLBRD *+ (post-increment). TBLPTR is point-
ing to odd address again.
7. If location doesn’t verify, go back to step 4.
8. If location does verify, begin 3x overprogram-
ming.
The TBLWT instruction offers flexibility with multiple
addressing modes: pre-increment, post-increment,
post decrement, and no change of the TBLPTR. These
modes eliminate the need for the increment address
command sequence.
FIGURE 2-17: DATA BUFFERING SCHEME FOR ICSP
Buffer Register
Program Memory
bank 0
(Even Address)
Program Memory
bank 1
(Odd Address)
TBLWT
Odd or Even
TBLWT
Odd or Even
TBLRD
TABLAT Register
addressaddress
EvenOdd
TBLRD
RB7
Data shifted into
TABLAT and
Buffer registers
2000 Microchip Technology Inc. DS39028A-page 3-119
PIC18CXXX
2.6.5 PROGRAMMING INSTRUCTION
SEQUENCE
The series of instructions needed to execute a pro-
gramming sequence is as follows. Many of the instruc-
tion sequences used in the following example are also
shown in previous sections.
NOP ; 4-bit instruction
; Set up low byte
; of program address
MOVLW Low_Byte_Address ; = 00
NOP ; 4-bit instruction
MOVWF TBLPTRL, 0
NOP ; 4-bit instruction
; Set up high byte
; of program
; address
MOVLW High_Byte_Address ; = 00
NOP ; 4-bit instruction
MOVWF TBLPTRH, 0
NOP ; 4-bit instruction
; Set up upper byte
; of program
; address
MOVLW Upper_Byte_Address; = 00
NOP ; 4-bit instruction
MOVWF TBLPTRU, 0 ; Program data byte
; included in TBLWT
; instruction
; sequence
TBLWT+* ; TBLPTR = 000000h
A write of a program memory location with an odd or an
even address causes a long write cycle in ICSP mode.
The 16-bit data is encoded in the TBLWT sequence and
is loaded into the temporary buffer register for word
wide writes.
The user must wait 100 µs for the long write to com-
plete before the next instruction is executed.
2.6.6 VERIFY SEQUENCE
The table pointer = 000001h in the last example. A
TBLRD will then read the odd address byte of the cur-
rent program word address location first. The verify
sequence will be as follows:
; Read/verify high byte first
TBLRD*-
; TBLPTR = 0000 post-dec
; Read/verify low byte
TBLRD*
The first TBLRD decrements the table pointer to point to
the even address byte of the current program word.
After the first and second cycle of the TBLRD are per-
formed, all 8-bits of data are shifted out on RB7. The
fetch of the second TBLRD occurs on the next 4 clock
cycles. The second TBLRD does not modify the table
pointer address. This allows another programming
cycle (TBLWT+*) to take place if the verify doesn’t
match the program data without having to update the
table pointer.
If the contents of the verify do not match the intended
program data word, then the TBLWT instruction must be
repeated with the correct contents of the current pro-
gram word. Therefore, only one instruction needs to be
performed to repeat the programming cycle:
TBLWT+*
2.6.7 3X OVER PROGRAMMING
Once a location has been both programmed and veri-
fied over a range of voltages, 3x over programming
should be applied. In other words, apply three times the
number of programming pulses that were required to
program a location in memory, to ensure a solid pro-
gramming margin.
This means that every location will be programmed a
minimum of 4 times (1 + 3x over programming).
PIC18CXXX
DS39028A-page 3-120 2000 Microchip Technology Inc.
FIGURE 2-18: DETAILED PROGRAMMING FLOW CHART – PROGRAM MEMORY
Start
Execute MOVLW
for 4 clock cycles
MCLR = VPP,
RB6, RB7 = 0
Execute FNOP
for four clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Hold CPU,
Shift in TBLRD *
for 4 clock cycles
Execute 1st cycle
TBLWT +*, and shift in
Wait 100 µsec to
ensure programming
A
Execute 2nd cycle
TBLWT +* for 4 clock cycles
Shift in TBLRD *-
for 4 clock cycles
N = 0
Execute 1st and 2nd cycle
TBLRD *- for 8 clock cycles
Shift Data Out
for 8 clock cycles
Verify?
No
Yes
N = N + 1
N > 25? Yes
No
Report
Programming
Failure
shift in 4-bit NOP
Shift in 16-bit MOVLW Low_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
and shift in 4-bit NOP
Shift in 16-bit MOVLW High_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Execute MOVWF
for 4 clock cycles
Shift in 16-bit MOVWF TBLPTRL
instruction for 16 clock cycles
4-bit instruction = NOP,
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRH
instruction for 16 clock cycles
4-bit instruction = NOP,
first 4-bits of data
for 4 clock cycles
Execute 1st and 2nd cycle
TBLRD * for 8 clock cycles
Shift Data Out
for 8 clock cycles
B
Shift in 16-bit MOVLW Upper_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Execute MOVWF
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRU
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute current instruction
for 4 clock cycles, and
shift in 4-bit TBLWT+*
Hold RB6
Clock high
Clock Low
for Discharge
Hold RB6
Clock high (P10)
2000 Microchip Technology Inc. DS39028A-page 3-121
PIC18CXXX
FIGURE 2-19: DETAILED PROGRAMMING FLOW CHART – PROGRAM MEMORY (CONTINUED)
A
Execute current instruction,
Shift in TBLWT *+
for 4 clock cycles
N = 1?
Yes
No
N = 3 * N
All locations
No
Yes
programmed?
To B
Wait 100 µsec to
ensure programming Report
@ VDDMIN
Verify
Error
Report
@ VDDMAX
Verify
Error
No
No
Yes
Yes
End
Verify all Locations
@ VDDMIN
Data Correct?
Verify all Locations
@ VDDMAX
Data Correct?
N = N - 1
Execute 1st cycle
TBLWT *+ or *, and shift in
first 4-bits of data
for 4 clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Execute 2nd cycle
TBLWT * for 4 clock cycles
Shift in TBLWT *
for 4 clock cycles
Execute 2nd cycle
TBLWT * for 4 clock cycles
Shift in TBLWT *+
for 4 clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Execute current instruction
for 4 clock cycles, and
shift in 4-bit TBLRD+*
Hold RB6 high
Wait 100 µS
Hold RB6 high
Clock Low
for Discharge
PIC18CXXX
DS39028A-page 3-122 2000 Microchip Technology Inc.
2.6.8 LOAD CONFIGURATION
The Configuration registers are located in ok memory,
and are only addressable when the high address bit of
the TBLPTR (bit 21) is set. Test program memory con-
tains test memory, configuration registers, calibration
registers, and ID locations. The desired address must
be loaded into all three bytes of the table pointer to pro-
gram specific ID locations or the configuration bits. To
program the configuration registers, the following
sequence must be followed:
NOP ; 4-bit instruction
; shift in 16-bit
; MOVLW instruction
MOVLW 03h
NOP ; 4-bit instruction
; shift in 16-bit
; MOVWF instruction
; Enable Test memory
MOVWF TBLPTRU, 0
NOP ; 4-bit instruction
; shift in 16-bit
; MOVLW instruction
MOVLW Low_Config_Address
NOP ; 4-bit instruction
; shift in 16-bit
; MOVWF instruction
MOVWF TBLPTRL, 0
NOP ; 4-bit instruction
; shift in 16-bit
; MOVLW instruction
MOVLW ; High_Config_Address
NOP ; 4-bit instruction
; shift in 16-bit
; MOVWF instruction
MOVWF TBLPTRH, 0
NOP ; 4-bit instruction
; shift in 16-bit
; MOVLW instruction
TBLWT *+
; 16-bits of data are
; shifted in for write
; of config1L and
; config1H TBLWT is a
; 4-bit special
; instruction Wait
; 100 µsec for programming
2.6.9 END PROGRAMMING
When programming occurs, 16 bits of data are pro-
grammed into memory. The 16-bits of data are shifted
in during the TBLWT sequence. After the programming
command (TBLWT) has been executed, the user must
wait for 100 µs until programming is complete, before
another command can be executed by the CPU. There
is no command to end programming.
RB6 must remain high for as long as programming is
desired. When RB6 is lowered programming will cease.
After the falling edge occurs on RB6, RB6 must be held
low for a period of time so that a high voltage discharge
can be performed to ensure that the program array isn’t
stressed at high voltage during execution of the next
instruction. The high voltage discharge will occur while
RB6 is low following the programming time.
2000 Microchip Technology Inc. DS39028A-page 3-123
PIC18CXXX
FIGURE 2-20: SYMBOLIC PROGRAMMING FLOW CHART – CONFIG WORD / ID LOCATION
ICSP Command
INCREMENT ADDRESS
START
MCLR = VIHH
N = 0
ICSP Command
LOAD CONFIGURATION
Program ID Loc?
Report
Programming
Failure
ICSP Command
BEGIN PROGRAMMING
Wait approx 100 µs
N = N - 1
4.75V < VDD < 5.25V
MCLR = VSS
No
N = 3N
No
Yes
No
Address = 300000h
N > 25?
ICSP Command
LOAD DATA
Address = 300000h?
ICSP Command
LOAD ADDRESS
Address = 300000h
ICSP Command
BEGIN PROGRAMMING
Wait approx 100 µs
ICSP Command
READ DATA
Data Correct?
Yes
ICSP Command
LOAD DATA
ICSP Command
BEGIN PROGRAMMING
Wait approx 100 µs
N = N - 1
N = 0?
N = 100
No
Data Correct?
Report
Programming
Failure
Yes
ICSP Command
READ DATA
Verify all Locations
@ VDDMIN
Data Correct?
Verify all Locations
@ VDDMAX
Data Correct?
DONE
Report
@ VDDMIN
Verify
Error
Report
@ VDDMAX
Verify
Error
No
No
Yes
Yes
Yes
N = 0
N = 0?
PIC18CXXX
DS39028A-page 3-124 2000 Microchip Technology Inc.
FIGURE 2-21: DETAILED PROGRAMMING FLOW CHART – CONFIG WORD
START
MCLR = VIHH
4.75V < VDD < 5.25V
MCLR = VSS
N = 99
Wait 100 µsec to
ensure programming
N = N - 1
Execute FNOP
for four clock cycles
shift in 4-bit NOP
Shift in 16-bit MOVLW 00
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRH
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVWF
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVLW 00
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBPLTRL
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute last fetched inst.
for 4 clock cycles
and shift in 4-bit TBLWT+*
TBPLTR = 0x300000h
Shift in last 12-bits of data
for 12 clock cycles
Execute 1st cycle
TBLWT, and shift in
Execute 2nd cycle
TBLWT for 4 clock cycles
Shift in TBLWT *
for 4 clock cycles
first 4-bits of config. reg.
for 4 clock cycles
CONFIG1L and CONFIG1H
N = 1?
Execute 2nd cycle
TBLWT* for 4 clock cycles
Shift in TBLWT *-
for 4 clock cycles
Shift in 16-bit MOVLW 30
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRU
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVWF
for 4 clock cycles
and shift in 4-bit NOP
A
B
Yes
No
Wait 100 µsec to
ensure programming
Clock Low
for Discharge
RB6 High
2000 Microchip Technology Inc. DS39028A-page 3-125
PIC18CXXX
FIGURE 2-22: DETAILED PROGRAMMING FLOW CHART – CONFIG WORD
Shift in TBLRD*+
for 4 clock cycles
Execute 1st and 2nd cycle
TBLRD*+ for 8 clock cycles
Shift Data Out
for 8 clock cycles
Execute 1st and 2nd cycle
TBLRD*+ for 8 clock cycles
Shift Data Out
for 8 clock cycles
Verify?
Yes
Report
@ VDDMIN
Verify
Error
Report
@ VDDMAX
Verify
Error
Yes
Yes
Verify all ID_Locations
@ VDDMIN
Verify all Locations
@ VDDMAX
All
locations
Report
Verify
Error
No
Data Correct? No
Data Correct?
programmed?
Wait 100 µsec to
ensure programming
Execute 2nd cycle
TBLWT *- for 4 clock cycles
Shift in TBLRD*+
for 4 clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Execute 1st cycle
TBLWT*-, and shift in
first 4-bits of config. reg.
for 4 clock cycles
B
A
DONE
No
No
Yes
PIC18CXXX
DS39028A-page 3-126 2000 Microchip Technology Inc.
FIGURE 2-23: DETAILED PROGRAMMING FLOW CHART – ID LOCATION
Start
Execute MOVLW
for 4 clock cycles
MCLR = VPP,
RB6, RB7 = 0
Execute FNOP
for four clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Shift in TBLRD *
for 4 clock cycles
Execute 1st cycle
TBLWT +*, and shift in
Wait 100 µsec to
ensure programming
A
Execute 2nd cycle
TBLWT +* for 4 clock cycles
Shift in TBLRD *-
for 4 clock cycles
N = 0
Execute 1st and 2nd cycle
TBLRD *- for 8 clock cycles
Shift Data Out
for 8 clock cycles
Verify?
No
Yes
N = N + 1
N > 25? Yes
No
Report
Programming
Failure
shift in 4-bit NOP
Shift in 16-bit MOVLW Low_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
and shift in 4-bit NOP
Shift in 16-bit MOVLW High_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Execute MOVWF
for 4 clock cycles
Shift in 16-bit MOVWF TBLPTRL
instruction for 16 clock cycles
4-bit instruction = NOP,
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRH
instruction for 16 clock cycles
4-bit instruction = NOP,
first 4-bits of data
for 4 clock cycles
Execute 1st and 2nd cycle
TBLRD * for 8 clock cycles
Shift Data Out
for 8 clock cycles
B
Shift in 16-bit MOVLW Upper_Addr
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute MOVLW
for 4 clock cycles
and shift in 4-bit NOP
Execute MOVWF
for 4 clock cycles
and shift in 4-bit NOP
Shift in 16-bit MOVWF TBLPTRU
instruction for 16 clock cycles
4-bit instruction = NOP,
Execute current instruction
for 4 clock cycles, and
shift in 4-bit TBLWT+*
2000 Microchip Technology Inc. DS39028A-page 3-127
PIC18CXXX
FIGURE 2-24: DETAILED PROGRAMMING FLOW CHART – ID LOCATIONS (CONTINUED)
A
Execute current instruction,
Shift in TBLWT *+
for 4 clock cycles
N = 1?
Yes
No
N = 3 * N
All locations
No
Yes
programmed?
B
Wait 100 µsec to
ensure programming
Report
@ VDDMIN
Verify
Error
Report
@ VDDMAX
Verify
Error
No
No
Yes
Yes
End
Verify all Locations
@ VDDMIN
Data Correct?
Verify all Locations
@ VDDMAX
Data Correct?
N = N - 1
Wait 100 µsec to
ensure programming
Execute 1st cycle
TBLWT *+ or *, and shift in
first 4-bits of data
for 4 clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Execute 2nd cycle
TBLWT * for 4 clock cycles
Shift in TBLWT *
for 4 clock cycles
Execute 2nd cycle
TBLWT * for 4 clock cycles
Shift in TBLWT *+
for 4 clock cycles
Execute 1st cycle
TBLWT *+, and shift in
first 4-bits of data
for 4 clock cycles
Shift in last 12-bits of data
for 12 clock cycles
Execute 2nd cycle TBLWT *+
for 4 clock cycles, and
shift in 4-bit TBLWT +*
PIC18CXXX
DS39028A-page 3-128 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The configuration bits can be programmed (read as ’0’)
or left unprogrammed (read as ’1’) to select various
device configurations. These bits are mapped starting
at program memory location 300000h.
The user will note that address 300000h is beyond the
user program memory space. In fact, it belongs to the
configuration memory space (300000h – 3FFFFFh).
TABLE 3-1: CONFIGURATION BITS AND DEVICE IDS
Filename Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Default /
unprogrammed
value
300000h CONFIG1L CP CP CP CP CP CP CP CP 1111 1111
300001h CONFIG1H RES1RES1OSCSEN — — FOSC2 FOSC1 FOSC0 111- -111
300002h CONFIG2L — — — — BORV1 BORV0 BODEN PWRTEN ---- 1111
300003h CONFIG2H — — — — WDTPS2 WDTPS1 WDTPS0 WDTEN ---- 1111
300005h CONFIG3H — — — — — — — CCP2MX ---- ---1
300006h CONFIG4L — — — — — — RES1STVREN ---- --11
3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 ---- ----
3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 ---- ----
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, grayed cells are unimplemented read
as 0
Note 1: Resvered – Read as 1.
2000 Microchip Technology Inc. DS39028A-page 3-129
PIC18CXXX
Register 3-1: Configuration Register 1 High (CONFIG1H: Byte Address 300001h)
Register 3-2: Configuration Register 1 Low (CONFIG1L: Byte Address 300000h)
R/P-1 R/P-1 R/P-1 U-0 U-0 R/P-1 R/P-1 R/P-1
Reserved Reserved OSCSEN——FOSC2 FOSC1 FOSC0
bit 7 bit 0
bit 7-6 Reserved: Read as ’1’
bit 5 OSCSEN: Oscillator System Clock Switch Enable bit
1 =Oscillator system clock switch option is disabled (OSCA is source)
0 =Oscillator system clock switch option is enabled
(OSCA → OSCB, OSCB → OSCA switching is enabled)
bit 4-3 Reserved: Read as ’0’
bit 2-0 FOSC2:FOSC0: Oscillator Selection bits
111 = RC oscillator w/ OSC2 configured as RA6
110 = HS oscillator with PLL enabled/CLock frequency = (4 x Fosc1)
101 = EC oscillator w/ OSC2 configured as RA6
100 = EC oscillator w/ OSC2 configured as divide by 4 clock output
011 = RC oscillator
010 = HS oscillator
001 = XT oscillator
000 = LP oscillator
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1 R/P-1
CP CP CP CP CP CP CP CP
bit 7 bit 0
CP: Code Protection bits (apply when in Code Protected Microcontroller Mode)
1 = Program memory code protection off
0 = All of program memory code protected
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
PIC18CXXX
DS39028A-page 3-130 2000 Microchip Technology Inc.
Register 3-3: Configuration Register 2 High (CONFIG2H: Byte Address 300003h)
Register 3-4: Configuration Register 2 Low (CONFIG2L: Byte Address 300002h)
U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1
—— ——WDTPS2 WDTPS1 WDTPS0 WDTEN
bit 7 bit 0
bit 7-4 Reserved: Read as ’0’
bit 3-1 WDTPS2:WDTPS0: Watchdog Timer Postscale Select bits
111 = 1:128
110 = 1:64
101 = 1:32
100 = 1:16
011 = 1:8
010 = 1:4
001 = 1:2
000 = 1:1
bit 0 WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled (control is placed on the SWDTE bit)
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
U-0 U-0 U-0 U-0 R/P-1 R/P-1 R/P-1 R/P-1
—— ——BORV1 BORV0 BOREN PWRTEN
bit 7 bit 0
bit 7-4 Reserved: Read as ’0’
bit 3-2 BORV1:BORV0: Brown-out Reset Voltage bits
11 = VBOR set to 2.5V
10 = VBOR set to 2.7V
01 = VBOR set to 4.2V
00 = VBOR set to 4.5V
bit 1 BOREN: Brown-out Reset Enable bit (1)
1 = Brown-out Reset enabled
0 = Brown-out Reset disabled
Enabling Brown-out Reset automatically enables the Power-up Timer (PWRT) regardless of the value of
bit PWRTEN. Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
bit 0 PWRTEN: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
Enabling Brown-out Reset automatically enables the Power-up Timer (PWRT) regardless of the value of
bit PWRTEN. Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
2000 Microchip Technology Inc. DS39028A-page 3-131
PIC18CXXX
Register 3-5: Configuration Register 3 High (CONFIG3H: Byte Address 300005h)
Register 3-6: Configuration Register 4 Low (CONFIG3H: Byte Address 300006h)
3.1 ID Locations
A user may store identification information (ID) in 8 ID
locations. The ID locations are mapped in
[0x200000:0x200007]. It is recommended that the user
use only the 4 least significant bits of each ID location.
The ID locations do not read out in a scrambled fashion
after code protection is enabled. For all devices it is rec-
ommended that all ID locations are written as ‘1111
bbbb’ where bbbb is the ID information. When the
upper four bits of an ID location is written as ‘1111’, the
resulting opcode when executed is read as a NOP. This
allows Reset testing of test program memory after ID
locations have been programmed.
U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/P-1
—— —————CCP2MX
bit 7 bit 0
bit 7-1 Reserved: Read as ’0’
bit 0 CCP2MX: CCP2 Mux bit
1 = CCP2 input/output is multiplexed with RC1
0 = CCP2 input/output is multiplexed with RB3
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
U-0 U-0 U-0 U-0 U-0 U-0 R/P-1 R/P-1
—— ————Reserved STVREN
bit 7 bit 0
bit 7-2 Reserved: Read as ’0’
bit 1 Reserved: Maintain this bit set.
bit 0 STVREN: Stack Full/Underflow Reset Enable bit
1 = Stack Full/Underflow will cause reset
0 = Stack Full/Underflow will not cause reset
Legend
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
- n = Value when device is unprogrammed u = Unchanged from programmed state
PIC18CXXX
DS39028A-page 3-132 2000 Microchip Technology Inc.
3.2 Embedding Configuration Word Information in the Hex File
3.3 CHECKSUM COMPUTATION
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
To allow portability of code, a PIC18C4X programmer is required to read the configuration word locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, all configuration word information must be included. An
option to not include the configuration word information may be provided. When embedding configuration word infor-
mation in the hex file, it should be to address FE00h.
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
TABLE 3-2: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank
Value
0xAA at 0
and max
address
PIC18C452
Disable SUM[0C000:0x7FFF] + CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2
& 0x0F + CFGW3 & 0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 +
CFGW6 & 0x03 + CFGW7 & 0x00
0x8148 0x809E
Enabled CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2 & 0xF + CFGW3 & 0x0F
+ CFGW4 & 0x00 + CFGW5 & 0x01 + CFGW6 & 0x03 + CFGW7 &
0x00 + SUM_ID
0x005E 0x0068
PIC18C442
Disable SUM[0x000:0x3FFF] + CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2
& 0x0F + CFGW3 & 0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 +
CFGW6 & 0x03 + CFGW7 & 0x00
0xC148 0xC09E
Enabled CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2 & 0x0F + CFGW3 &
0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 + CFGW6 & 0x03 +
CFGW7 & 0x00 + SUM_ID
0x0062 0x006C
PIC18C252
Disable SUM[0x000:0x7FFF] + CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2
& 0x0F + CFGW3 & 0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 +
CFGW6 & 0x03 + CFGW7 & 0x00
0x8148 0x809E
Enabled CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2 & 0x0F + CFGW3 &
0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 + CFGW6 & 0x03 +
CFGW7 & 0x00 + SUM_ID
0x005E 0x0068
PIC18C242
Disable SUM[0x000:0x3FFF] + CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2
& 0x0F + CFGW3 & 0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 +
CFGW6 & 0x03 + CFGW7 & 0x00
0xC148 0xC09E
Enabled CFGW0 & 0xFF + CFGW1 & 0x27 + CFGW2 & 0x0F + CFGW3 &
0x0F + CFGW4 & 0x00 + CFGW5 & 0x01 + CFGW6 & 0x03 +
CFGW7 & 0x00 + SUM_ID
0x0062 0x006C
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a to b inclusive]
SUM_ID = Byte-wise sum of lower four bits of all ID locations
+ = Addition
& = Bitwise AND
2000 Microchip Technology Inc. DS39028A-page 3-133
PIC18CXXX
4.0 AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +70°C, unless otherwise stated, (25°C is recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.25V, unless otherwise stated.
Parameter
No. Sym Characteristic Min Typ†Max Units Conditions
VIHH Programming Voltage on VPP/
MCLR pin and TEST pin.
VDD + 4.0 —13.25 V
IPP Programming current on MCLR pin 25 50 mA
P1 TSER Serial setup time 20 ——ns
P2 TSCLK Serial Clock period 100 ——ns
P3 TSET1 Input Data Setup Time to serial
clock ↓
15 ——ns
P4 THLD1 Input Data Hold Time from serial
clock ↓
15 ——ns
P5 TDLY1Delay between last clock ↓ to first
clock ↑ of next command
20 ——ns
P6 TDLY2Delay between last clock ↓ of com-
mand byte to first clock ↑ of read of
data word
20 ——ns
P8 TDLY4 Data input not driven to next clock
input
1——ns
P9 TDLY5 RB6 high time (minimum program-
ming time)
100 ——µs
P10 TDLY6 RB6 low time after programming
(high voltage discharge time)
100 ——ns
* These parameters are characterized but not tested.
† Data in “Ty p ” column is at 5V, 25×C unless otherwise stated. These parameters are for design guidance only and are not
tested.
PIC18CXXX
DS39028A-page 3-134 2000 Microchip Technology Inc.
NOTES:
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-135
PIC16F62X
This document includes the programming
specifications for the following devices:
•PIC16F627
•PIC16F628
• PIC16LF627
• PIC16LF628
1.0 PROGRAMMING THE
PIC16F62X
The PIC16F62X is programmed using a serial method.
The serial mode will allow the PIC16F62X to be pro-
grammed while in the users system. This allows for
increased design flexibility. This programming specifi-
cation applies to PIC16F62X devices in all packages.
PIC16F62X devices may be programmed using a sin-
gle +5 volt supply (low voltage programming mode).
1.1 Hardware Requirements
The PIC16F62X requires one programmable power
supply for VDD (4.5V to 5.5V) and a VPP of 12V to 14V
or VPP of (4.5V to 5.5V) when using low voltage. Both
supplies should have a minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC16F62X allows pro-
gramming of user program memory, data memory, spe-
cial locations used for ID, and the configuration word.
PIN Diagram
PDIP, SOIC
RA2/AN2/V
REF
RA3/AN3/CMP1
RA4/T0CKI/CMP2
RA5/MCLR/THV
V
SS
RB0/INT
RB1/RX/DT
RB2/TX/CK
RB3/CCP1
RA1/AN1
RA0/AN0
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT
V
DD
RB7/T1OSI
RB6/T1OSO/T1CKI
RB5
RB4/PGM
• 1
2
3
4
5
7
8
9
18
17
16
15
14
12
11
10
PIC16F62X
613
RA2/AN2/VREF
RA3/AN3/CMP1
RA4/T0CKI/CMP2
RA5/MCLR/THV
VSS
RB0/INT
RB1/RX/DT
RB2/TX/CK
RB3/CCP1
RA1/AN1
RA0/AN0
RA7/OSC1/CLKIN
RA6/OSC2/CLKOUT
VDD
RB7/T1OSI
RB6/T1OSO/T1CKI
RB5
RB4/PGM
• 1
2
3
4
5
7
8
9
18
17
16
15
14
12
11
10
PIC16F62X
6
13
VDD
VSS
19
20
PIN DESCRIPTIONS (DURING PROGRAMMING): PIC16F62X
Pin Name
During Programming
Function Pin Type Pin Description
RB4 PGM I Low voltage programming input if configuration bit
equals 1
RB6 CLOCK I Clock input
RB7 DATA I/O Data input/output
MCLR VTEST MODE P* Program Mode Select
VDD VDD P Power Supply
VSS VSS P Ground
Legend: I = Input, O = Output, P = Power
*In the PIC16F62X, the programming high voltage is internally generated. To activate the programming mode, high voltage needs
to be applied to MCLR input. Since the MCLR is used for a level source, this means that MCLR does not draw any significant current.
In-Circuit Serial Programming for PIC16F62X FLASH MCUs
PIC16F62X
DS30034A-page 3-136 Preliminary 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x7FFF. In programming mode the program memory
space extends from 0x0000 to 0x3FFF, with the first
half (0x0000-0x7FFF) being user program memory and
the second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x7FFF
and wrap to 0x000, 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ‘1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode as described in
Section 2.3.
In the configuration memory space, 0x2000-0x200F
are physically implemented. However, only locations
0x2000 through 0x2007 are available. Other locations
are reserved. Locations beyond 0x200F will physically
access user memory. (See Figure 2-1).
2.2 ID Locations
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000 :
0x2003]. It is recommended that the user use only the
four least significant bits of each ID location. In some
devices, the ID locations read-out in an unscrambled
fashion after code protection is enabled. For these
devices, it is recommended that ID location is written as
“11 1111 1000 bbbb” where ‘bbbb’ is ID information.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 4-1.
To understand the scrambling mechanism after code
protection, refer to Section 3-1.
FIGURE 2-1: PROGRAM MEMORY MAPPING
1FFF
2000
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000
2001
2002
2003
2005
2006
2007
2008
3FFF
0x1FF
Not Implemented
Implemented
1 KW
Implemented
2004
Implemented
2 KW
Implemented
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-137
PIC16F62X
2.3 Program/Verify Mode
The program/verify mode is entered by holding pins
RB6 and RB7 low while raising MCLR pin from VIL to
VIHH (high voltage) or by applying VDD to MCLR and
raising RB3 from VIL to VDD. Once in this mode the user
program memory and the configuration memory can be
accessed and programmed in serial fashion. The mode
of operation is serial, and the memory that is accessed
is the user program memory. RB6 and RB7 are Schmitt
Trigger Inputs in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
The normal sequence for programming is to use the
load data command to set a value to be written at the
selected address. Issue the begin programming com-
mand followed by read data command to verify, and
then increment the address.
A device reset will clear the PC and set the address to
0. The “increment address” command will increment
the PC. The “load configuration” command will se the
PC to 0x2000. The available commands are shown in
Ta bl e 2 - 1 .
2.3.1 LOW-VOLTAGE PROGRAMMING MODE
When LVP bit is set to ‘1’, the low-voltage programming
entry is enabled. Since the LVP configuration bit allows
low voltage programming entry in its erased state, an
erased device will have the LVP bit enabled at the fac-
tory. While LVP is ‘1’, RB4 is dedicated to low voltage
programming. Bring MCLR to VDD and then RB4 to
VDD to enter programming mode. All other specifica-
tions for high-voltage ICSP™ apply.
To disable low voltage mode, the LVP bit must be pro-
grammed to ‘0’. This must be done while entered with
high voltage entry mode (LVP bit= 1). RB4 is now a
general purpose I/O pin.
2.3.2 SERIAL PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RB6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin RB7 is required to have a minimum
setup and hold time (see AC/DC specifications) with
respect to the falling edge of the clock. Commands that
have data associated with them (read and load) are
specified to have a minimum delay of 1 µs between the
command and the data. After this delay, the clock pin is
cycled 16 times with the first cycle being a start bit and
the last cycle being a stop bit. Data is also input and
output LSB first.
Therefore, during a read operation the LSB will be
transmitted onto pin RB7 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of
the clock. To allow for decoding of commands and
reversal of data pin configuration, a time separation of
at least 1 µs is required between a command and a
data word (or another command).
The commands that are available are:
2.3.2.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits in a “data
word,” as described above, to be programmed into the
configuration memory. A description of the memory
mapping schemes of the program memory for normal
operation and configuration mode operation is shown
in Figure 2-1. After the configuration memory is
entered, the only way to get back to the user program
memory is to exit the program/verify test mode by tak-
ing MCLR low (VIL).
Note: The OSC must not have 72 osc clocks
while the device MCLR is between VIL and
VIHH.
PIC16F62X
DS30034A-page 3-138 Preliminary 2000 Microchip Technology Inc.
2.3.2.2 LOAD DATA FOR PROGRAM MEMORY
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
TABLE 2-1: COMMAND MAPPING FOR PIC16F627/PIC16F628
Command Mapping (MSB … LSB) Data
Load Configuration XX00000, data (14), 0
Load Data for Program Memory XX00100, data (14), 0
Read Data from Program Memory XX01000, data (14), 0
Increment Address XX0110
Begin Erase Programming Cycle 001000
Begin Programming Only Cycle 011000
Load Data for Data Memory XX00110, data (14), 0
Read Data from Data Memory XX01010, data (14), 0
Bulk Erase Program Memory XX1001
Bulk Erase Data Memory XX1011
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-139
PIC16F62X
FIGURE 2-2: PROGRAM FLOW CHART - PIC16F62X PROGRAM MEMORY
Start
Set VDD = VDDP
Program Cycle
Read Data
Command
Data Correct?
Report
Programming
Failure
All Locations
Done?
Verify all
Locations @
VDDMIN
Data Correct?
Verify all
Locations @
VDDMAX
Data Correct?
Done
Increment
Address
Command
Report Verify
Error @
VDDMIN
Report Verify
Error @
VDDMAX
Load Data
Command
Begin
Programming
Command
Wait 2 ms
PROGRAM CYCLE
No
No
No
No
PIC16F62X
DS30034A-page 3-140 Preliminary 2000 Microchip Technology Inc.
FIGURE 2-3: PROGRAM FLOW CHART - PIC16F62X CONFIGURATION MEMORY
Program ID
Start
Load
Configuration
Data
Location? Program Cycle Read Data
Command
Data Correct?
Report
Programming
Failure
Increment
Address
Command
Address =
0x2004?
Increment
Address
Command
Increment
Address
Command
Increment
Address
Command
Program
Cycle
(Config. Word)
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Report Program
Configuration
Word Error
Done
Ye s
No
No
Ye s
Ye sNo
No
Ye s
Ye s
No
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-141
PIC16F62X
2.3.2.3 LOAD DATA FOR DATA MEMORY
After receiving this command, the chip will load in a 14-
bit “data word” when 16 cycles are applied. However,
the data memory is only 8-bits wide, and thus only the
first 8-bits of data after the start bit will be programmed
into the data memory. It is still necessary to cycle the
clock the full 16 cycles in order to allow the internal cir-
cuitry to reset properly. The data memory contains 64
words. Only the lower 8-bits of the PC are decoded by
the data memory, and therefore if the PC is greater than
0x3F, it will wrap around and address a location within
the physically implemented memory. If the device is
code protected, the data is read as all zeros.
2.3.2.4 READ DATA FROM PROGRAM
MEMORY
After receiving this command, the chip will transmit
data bits out of the program memory (user or configu-
ration) currently accessed starting with the second ris-
ing edge of the clock input. The RB7 pin will go into
output mode on the second rising clock edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. A timing diagram of this command is
shown in Figure 5-2.
2.3.2.5 READ DATA FROM DATA MEMORY
After receiving this command, the chip will transmit
data bits out of the data memory starting with the sec-
ond rising edge of the clock input. The RB7 pin will go
into output mode on the second rising edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. As previously stated, the data memory is 8-
bits wide, and therefore, only the first 8-bits that are out-
put are actual data.
2.3.2.6 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.3.2.7 BEGIN ERASE/PROGRAM CYCLE
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes an erase before write. The user must allow for
both erase and programming cycle times for program-
ming to complete. No “end programming” command is
required.
2.3.2.8 BEGIN PROGRAMMING
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes a write. The user must allow for program cycle
time for programming to complete. No “end program-
ming” command is required.
This command is similar to the ERASE/PROGRAM
CYCLE command, except that a word erase is not
done. It is recommended that a bulk erase be per-
formed before starting a series of programming only
cycles.
2.3.2.9 BULK ERASE PROGRAM MEMORY
After this command is performed, the next program
command will erase the entire program memory.
To perform a bulk erase of the program memory, the fol-
lowing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase User Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
If the address is pointing to the test program memory
(0x2000 - 0x200F), then both the user memory and the
test memory will be erased. The configuration word will
not be erased, even if the address is pointing to location
0x2007.
2.3.2.10 BULK ERASE DATA MEMORY
To perform a bulk erase of the data memory, the follow-
ing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase Data Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
Note: If the device is code-protected, the BULK
ERASE command will not work.
Note: All BULK ERASE operations must take
place at 4.5 to 5.5 VDD range.
PIC16F62X
DS30034A-page 3-142 Preliminary 2000 Microchip Technology Inc.
2.4 Programming Algorithm Requires
Variable VDD
The PIC16F62X uses an intelligent algorithm. The
algorithm calls for program verification at VDDmin. as
well as VDDmax. Verification at VDDmin. guarantees
good “erase margin”. Verification at VDDmax guaran-
tees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (See Table 5-1).
VDDP =VCC range required during programming.
VDDmin. = minimum operating VDD spec for the part.
VDDmax.= maximum operating VDD spec for the part.
Programmers must verify the PIC16F62X at its speci-
fied VDD max. and VDDmin levels. Since Microchip may
introduce future versions of the PIC16F62X with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-143
PIC16F62X
3.0 CONFIGURATION WORD
The PIC16F62X has several configuration bits. These
bits can be set (reads ‘0’) or left unchanged (reads ‘1’)
to select various device configurations.
3.1 Device ID Word
The device ID word for the PIC16F62X is located at
2006h.
FIGURE 3-1: CONFIGURATION WORD FOR PIC16F877/876/873
TABLE 3-1:
Device Device ID Value
Dev Rev
PIC16F627 00 0111 111 x xxxx
PIC16F628 00 0111 001 x xxxx
CP1 CP0 CP1 CP0 - CPD LVP BODEN MCLRE FOSC2 PWRTE WDTE F0SC1 F0SC0 Register: CONFIG
Address 2007h
bit13 bit0
bit 13-10: CP1:CP0: Code Protection bits (2)
Code protection for 2K program memory
11 = Program memory code protection off
10 = 0400h-07FFh code protected
01 = 0200h-07FFh code protected
00 = 0000h-07FFhcode protected
Code protection for 1K program memory
11 = Program memory code protection off
10 = Program memory code protection off
01 = 0200h-03FFh code protected
00 = 0000h-03FFh code protected
bit 8: CPD: Data Code Protection bit(3)
1 = Data memory code protection off
0 = Data memory code protected
bit 7: LVP: Low Voltage Programming Enable
1 = RB4/PGM pin has PGM function, low voltage programming enabled
0 = RB4/PGM is digital I/O, HV on MCLR must be used for programming
bit 6: BODEN: Brown-out Detect Reset Enable bit (1)
1 = BOD reset enabled
0 = BOD reset disabled
bit 5: MCLRE: RA5/MCLR pin function select
1 = RA5/MCLR pin function is MCLR
0 = RA5/MCLR pin function is digital I/O, MCLR internally tied to VDD
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 4,1-0: FOSC2:FOSC0: Oscillator Selection bits(4)
111 = ER oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, Resistor on RA7/OSC1/CLKIN
110 = ER oscillator: I/O function on RA6/OSC2/CLKOUT pin, Resistor on RA7/OSC1/CLKIN
101 = INTRC oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
100 = INTRC oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
011 = EXTCLK: I/O function on RA6/OSC2/CLKOUT pin, CLKIN on RA7/OSC1/CLKIN
010 = HS oscillator: High speed crystal/resonator on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
001 = XT oscillator: Crystal/resonator on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
000 = LP oscillator: Low power crystal on RA6/OSC2/CLKOUT and RA7/OSC1/CLKIN
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE. Ensure
the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed. The entire pro-
gram EEPROM will be erased if the code protection is reduced.
3: The entire data EEPROM will be erased when the code protection is turned off. The calibration space in the test memory
is not erased.
4: When MCLR is asserted in INTRC or ER mode, the internal clock oscillator is disabled.
PIC16F62X
DS30034A-page 3-144 Preliminary 2000 Microchip Technology Inc.
4.0 CODE PROTECTION
For PIC16F62X devices, once code protection is
enabled, all program memory locations read all 0’s.
The ID locations and the configuration word read out in
an unscrambled fashion. Further programming is dis-
abled for the entire program memory as well as data
memory. It is possible to program the ID locations and
the configuration word.
4.1 Disabling Code-Protection
It is recommended that the following procedure be per-
formed before any other programming is attempted. It
is also possible to turn code protection off (code protect
bit = 1) using this procedure; however, all data within
the program memory and the data memory will be
erased when this procedure is executed, and thus,
the security of the data or code is not compro-
mised.
Procedure to disable code protect:
a) Execute load configuration (with a ‘1’ in bit 4,
code protect).
b) Increment to configuration word location
(0x2007)
c) Execute command (000001)
d) Execute command (000111)
e) Execute ‘Begin Programming’ (001000)
f) Wait 10 ms
g) Execute command (000001)
h) Execute command (000111)
4.2 Embedding Configuration Word and ID Information in the Hex File
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Specifically for the PIC16F62X, the EEPROM data memory should also be embedded in the hex file (see
Section 5.1).
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-145
PIC16F62X
4.3 CHECKSUM COMPUTATION
4.3.1 CHECKSUM
Checksum is calculated by reading the contents of the
PIC16F62X memory locations and adding up the
opcodes up to the maximum user addressable location,
e.g., 0x1FF for the PIC16F62X. Any carry bits exceed-
ing 16-bits are neglected. Finally, the configuration
word (appropriately masked) is added to the check-
sum. Checksum computation for each member of the
PIC16F62X devices is shown in Table 4-1.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 4-1: CHECKSUM COMPUTATION
Device
Code
Protect Checksum* Blank
Value
0x25E6 at 0
and max
address
PIC16F627 OFF SUM[0x0000:0x3FFF] + CFGW & 0x3DFF 0x39FF 0x05CD
0x200 : 0x3FF SUM[0x0000:0x01FF] + CFGW & 0x3DFF + SUM_ID 0x4DFE 0xFFB3
ALL 0x3BFE 0x07CC
PIC16F628 OFF SUM[0x0000:0x07FF] + CFGW & 0x3DFF 0x35FF 0x01CD
0x400 : 0xFFF SUM[0x0000:0x03FF] + CFGW & 0x3DFF +SUM_ID 0x5BFE 0x0DB3
0x200 : 0x7FF SUM[0x0000:0x01FF] + CFGW & 0x3DFF + SUM_ID 0x49FE 0xFBB3
ALL CFGW & 0x3DFF + SUM_ID 0x37FE 0x03CC
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a to b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example, ID0 = 0x1, ID1 = 0x2, ID3 = 0x3, ID4 = 0x4, then SUM_ID = 0x1234
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
PIC16F62X
DS30034A-page 3-146 Preliminary 2000 Microchip Technology Inc.
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
5.1 Embedding Data EEPROM Contents in Hex File
The programmer should be able to read data EEPROM information from a hex file and conversely (as an option) write
data EEPROM contents to a hex file along with program memory information and fuse information.
The 64 data memory locations are logically mapped starting at address 0x2100. The format for data memory storage
is one data byte per address location, LSB aligned.
TABLE 5-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY MODE
Standard Operating Conditions (unless otherwise stated)
Operating Temperature: 0°C ≤ TA ≤ +70°C
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V
Characteristics Sym Min Typ Max Units Conditions/Comments
General
VDD level for word operations, program
memory VDD 2.0 5.5 V
VDD level for word operations, data mem-
ory VDD 2.0 5.5 V
VDD level for bulk erase/write operations,
program and data memory VDD 4.5 5.5 V
High voltage on MCLR and
RA4/T0CKI for test-mode entry VIHH VDD + 3.5 13.5 V
MCLR rise time (VSS to VHH) for test
mode entry
tVHHR 1.0 µs
(RB6, RB7) input high level VIH1 0.8VDD V Schmitt Trigger input
(RB6, RB7) input low level VIL1 0.2VDD V Schmitt Trigger input
RB<7:4> setup time before MCLR↑
(test mode selection pattern setup time)
tset0 100 ns
RB<7:4> hold time after MCLR↑
(test mode selection pattern setup time)
thld0 5 µs
Serial Program/Verify
Data in setup time before clock↓tset1100 ns
Data in hold time after clock↓thld1100 ns
Data input not driven to next clock input
(delay required between command/data or
command/command)
tdly11.0 µs
Delay between clock↓ to clock↑ of next
command or data
tdly2 1.0 µs
Clock↑ to data out valid (during read data) tdly3 80 ns
Parallel Program/Verify
Data in setup time before clock↓tset01.0 µs
Data in hold time after clock↓thld01.0 µs
RB6 and RB7 setup time before clock↓tset11.0 µs
RB6 and RB7 hold time after clock↓thld1 1.0 µs
RA4/T0CKI (clock)↓ to (clock)↑tdly4 2.0 µs
RB7 (data/command select input) setup
before RA4/T0CKI (clock)↑
tset21.0 µs
RB7 (data/command select input) hold time
after RA4/T0CKI (clock)↓
thld21.0 µs
RA4/T0CKI (clock)↑ to data out valid tdly5 1.0 µs
RB6 (hi/lo select) valid to data out valid tdly6 1.0 µs
Erase cycle time tera 2 5 ms
Programming cycle time tprog 2 5 ms
Time delay from program to compare (HV
discharge time)
tdis 0.5 µs
2000 Microchip Technology Inc. Preliminary DS30034A-page 3-147
PIC16F62X
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
MCLR
VIHH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tset1
thld1
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
100ns min.
1µs min.
tdly2
12 3 4 5 6
0100XX
12 3 4 5 15
16
strt_bit stp_bit
100ns min.
}
thld0
}
}
}
MCLR
VIHH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
1010XX
12 3 4 5 15
16
100ns min.
}
}
tdly3
RB7 = input RB7 = output
RB7
input
thld0
strt_bit stp_bit
MCLR
VIHH
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
011 XX
12
100ns min.
}
}
X0
0
Next Command
PIC16F62X
DS30034A-page 3-148 Preliminary 2000 Microchip Technology Inc.
NOTES:
2000 Microchip Technology Inc. DS30262C-page 3-149
PIC16F8X
This document includes the programming
specifications for the following devices:
•PIC16F83
• PIC16CR83
•PIC16F84
• PIC16CR84
•PIC16F84A
•PIC16F877
1.0 PROGRAMMING THE PIC16F8X
The PIC16F8X is programmed using a serial method.
The serial mode will allow the PIC16F8X to be pro-
grammed while in the users system. This allows for
increased design flexibility. This programming specifi-
cation applies to PIC16F8X devices in all packages.
1.1 Hardware Requirements
The PIC16F8X requires one programmable power sup-
ply for VDD (4.5V to 5.5V) and a VPP of 12V to 14V. Both
supplies should have a minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC16F8X allows pro-
gramming of user program memory, data memory, spe-
cial locations used for ID, and the configuration word.
Pin Diagram
RA1
RA0
OSC1/CLKIN
OSC2/CLKOUT
VDD
RB7
RB6
RB5
RB4
RA2
RA3
RA4/T0CKI
MCLR
VSS
RB0/INT
RB1
RB2
RB3
•1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
PIC16F8X
PDIP, SOIC
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RD7/PSP7
RD6/PSP6
RD5/PSP5
RD4/PSP4
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
RD3/PSP3
RD2/PSP2
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3/VREF
RA4/T0CKI
RA5/AN4/SS
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
VDD
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RD0/PSP0
RD1/PSP1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
PIC16F877
PIN DESCRIPTIONS (DURING PROGRAMMING): PIC16F8X
Pin Name
During Programming
Function Pin Type Pin Description
RB6 CLOCK I Clock input
RB7 DATA I/O Data input/output
MCLR VTEST MODE P* Program Mode Select
VDD VDD P Power Supply
VSS VSS P Ground
Legend: I = Input, O = Output, P = Power
*In the PIC16F8X, the programming high voltage is internally generated. To activate the programming mode, high voltage needs to
be applied to MCLR input. Since the MCLR is used for a level source, this means that MCLR does not draw any significant current.
In-Circuit Serial Programming for PIC16F8X FLASH MCUs
PIC16F8X
DS30262C-page 3-150 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K), of which 1K (0x0000 - 0x03FF) is physi-
cally implemented. In actual implementation the on-
chip user program memory is accessed by the lower
10-bits of the PC, with the upper 3-bits of the PC
ignored. Therefore if the PC is greater than 0x3FF, it will
wrap around and address a location within the physi-
cally implemented memory. (See Figure 2-1).
In programming mode the program memory space
extends from 0x0000 to 0x3FFF, with the first half
(0x0000-0x1FFF) being user program memory and the
second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x1FFF
and wrap to 0x000 or 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ‘1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode as described in
Section 2.3.
In the configuration memory space, 0x2000-0x200F
are physically implemented. However, only locations
0x2000 through 0x2007 are available. Other locations
are reserved. Locations beyond 0x200F will physically
access user memory. (See Figure 2-1).
2.2 ID Locations
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000 :
0x2003]. It is recommended that the user use only the
four least significant bits of each ID location. In some
devices, the ID locations read-out in an unscrambled
fashion after code protection is enabled. For these
devices, it is recommended that ID location is written as
“11 1111 1000 bbbb” where ‘bbbb’ is ID information.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 4-2.
To understand the scrambling mechanism after code
protection, refer to Section 4.0.
2000 Microchip Technology Inc. DS30262C-page 3-151
PIC16F8X
FIGURE 2-1: PROGRAM MEMORY MAPPING
0
3FF
400
1FFF
2000
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Reserved
Configuration Word
2000
2001
2002
2003
2004
2005
2006
2007
2008
3FFF
Not Implemented
Not Implemented
Implemented
Implemented
1FF
Not Implemented
Not Implemented
Implemented
Implemented
0.5 KW 1 KW
Not Implemented
Implemented
8 KW
Implemented
PIC16F8X
DS30262C-page 3-152 2000 Microchip Technology Inc.
2.3 Program/Verify Mode
The program/verify mode is entered by holding pins
RB6 and RB7 low while raising MCLR pin from VIL to
VIHH (high voltage). Once in this mode the user pro-
gram memory and the configuration memory can be
accessed and programmed in serial fashion. The mode
of operation is serial, and the memory that is accessed
is the user program memory. RB6 and RB7 are Schmitt
Trigger Inputs in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
The normal sequence for programming is to use the
load data command to set a value to be written at the
selected address. Issue the begin programming com-
mand followed by read data command to verify, and
then increment the address.
2.3.1 SERIAL PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RB6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin RB7 is required to have a minimum
setup and hold time (see AC/DC specifications) with
respect to the falling edge of the clock. Commands that
have data associated with them (read and load) are
specified to have a minimum delay of 1 µs between the
command and the data. After this delay, the clock pin is
cycled 16 times with the first cycle being a start bit and
the last cycle being a stop bit. Data is also input and
output LSB first.
Therefore, during a read operation the LSB will be
transmitted onto pin RB7 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of
the clock. To allow for decoding of commands and
reversal of data pin configuration, a time separation of
at least 1 µs is required between a command and a
data word (or another command).
The commands that are available are:
2.3.1.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits in a “data
word,” as described above, to be programmed into the
configuration memory. A description of the memory
mapping schemes of the program memory for normal
operation and configuration mode operation is shown
in Figure 2-1. After the configuration memory is
entered, the only way to get back to the user program
memory is to exit the program/verify test mode by tak-
ing MCLR low (VIL).
Note: The OSC must not have 72 osc clocks
while the device MCLR is between VIL and
VIHH.
2000 Microchip Technology Inc. DS30262C-page 3-153
PIC16F8X
2.3.1.2 LOAD DATA FOR PROGRAM MEMORY
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
TABLE 2-1: COMMAND MAPPING FOR PIC16F83/CR83/F84/CR84
Command Mapping (MSB … LSB) Data
Load Configuration 0000000, data (14), 0
Load Data for Program Memory 0000100, data (14), 0
Read Data from Program Memory 0001000, data (14), 0
Increment Address 000110
Begin Programming 001000
Load Data for Data Memory 0000110, data (14), 0
Read Data from Data Memory 0001010, data (14), 0
Bulk Erase Program Memory 001001
Bulk Erase Data Memory 001011
TABLE 2-2: COMMAND MAPPING FOR PIC16F84A/PIC16F877
Command Mapping (MSB … LSB) Data
Load Configuration XX00000, data (14), 0
Load Data for Program Memory XX00100, data (14), 0
Read Data from Program Memory XX01000, data (14), 0
Increment Address XX0110
Begin Erase Programming Cycle 001000
Begin Programming Only Cycle 011000
Load Data for Data Memory XX00110, data (14), 0
Read Data from Data Memory XX01010, data (14), 0
Bulk Erase Program Memory XX1001
Bulk Erase Data Memory XX1011
PIC16F8X
DS30262C-page 3-154 2000 Microchip Technology Inc.
FIGURE 2-2: PROGRAM FLOW CHART - PIC16F8X PROGRAM MEMORY
Start
Set VDD = VDDP
Program Cycle
Read Data
Command
Data Correct?
Report
Programming
Failure
All Locations
Done?
Verify all
Locations @
VDDMIN
Data Correct?
Verify all
Locations @
VDDMAX
Data Correct?
Done
Increment
Address
Command
Report Verify
Error @
VDDMIN
Report Verify
Error @
VDDMAX
Load Data
Command
Begin
Programming
Command
Wait 10 ms
PROGRAM CYCLE
No
No
No
No
2000 Microchip Technology Inc. DS30262C-page 3-155
PIC16F8X
FIGURE 2-3: PROGRAM FLOW CHART - PIC16F8X CONFIGURATION MEMORY
Program ID
Start
Load
Configuration
Data
Location? Program Cycle Read Data
Command
Data Correct?
Report
Programming
Failure
Increment
Address
Command
Address =
0x2004?
Increment
Address
Command
Increment
Address
Command
Increment
Address
Command
Program
Cycle
(Config. Word)
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Report Program
Configuration
Word Error
Done
Ye s
No
No
Ye s
Ye sNo
No
Ye s
Ye s
No
PIC16F8X
DS30262C-page 3-156 2000 Microchip Technology Inc.
2.3.1.3 LOAD DATA FOR DATA MEMORY
After receiving this command, the chip will load in a 14-
bit “data word” when 16 cycles are applied. However,
the data memory is only 8-bits wide, and thus only the
first 8-bits of data after the start bit will be programmed
into the data memory. It is still necessary to cycle the
clock the full 16 cycles in order to allow the internal cir-
cuitry to reset properly. The data memory contains 64
words. Only the lower 8-bits of the PC are decoded by
the data memory, and therefore if the PC is greater than
0x3F, it will wrap around and address a location within
the physically implemented memory.
2.3.1.4 READ DATA FROM PROGRAM
MEMORY
After receiving this command, the chip will transmit
data bits out of the program memory (user or configu-
ration) currently accessed starting with the second ris-
ing edge of the clock input. The RB7 pin will go into
output mode on the second rising clock edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. A timing diagram of this command is
shown in Figure 5-2.
2.3.1.5 READ DATA FROM DATA MEMORY
After receiving this command, the chip will transmit
data bits out of the data memory starting with the sec-
ond rising edge of the clock input. The RB7 pin will go
into output mode on the second rising edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. As previously stated, the data memory is 8-
bits wide, and therefore, only the first 8-bits that are out-
put are actual data.
2.3.1.6 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.3.1.7 BEGIN ERASE/PROGRAM CYCLE
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes an erase before write. The user must allow for
both erase and programming cycle times for program-
ming to complete. No “end programming” command is
required.
2.3.1.8 BEGIN PROGRAMMING
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes a write. The user must allow for program cycle
time for programming to complete. No “end program-
ming” command is required.
This command is similar to the ERASE/PROGRAM
CYCLE command, except that a word erase is not
done. It is recommended that a bulk erase be per-
formed before starting a series of programming only
cycles.
2.3.1.9 BULK ERASE PROGRAM MEMORY
After this command is performed, the next program
command will erase the entire program memory.
To perform a bulk erase of the program memory, the fol-
lowing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase User Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
If the address is pointing to the test program memory
(0x2000 - 0x200F), then both the user memory and the
test memory will be erased. The configuration word will
not be erased, even if the address is pointing to location
0x2007
For PIC16F84 perform the following commands:
1. Issue Command 2 (write program memory).
2. Send out 3FFFH data.
3. Issue Command 1 (toggle select even rows).
4. Issue Command 7 (toggle select even rows).
5. Issue Command 8 (begin programming)
6. Delay 10 ms
7. Issue Command 1 (toggle select even rows).
8. Issue Command 7 (toggle select even rows).
Note: If the device is code-protected
(PIC16F84A), the BULK ERASE com-
mand will not work.
2000 Microchip Technology Inc. DS30262C-page 3-157
PIC16F8X
2.3.1.10 BULK ERASE DATA MEMORY
To perform a bulk erase of the data memory, the follow-
ing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase Data Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
For PIC16F84 perform the data memory).
5. Send out 3FFFH data.
6. Issue Command 1 (toggle select even rows).
7. Issue Command 7 (toggle select even rows).
8. Issue Command 8 (begin data)
9. Delay 10 ms
10. Issue Command 1 (toggle select even rows).
Issue Command 7 (toggle select even rows).
2.4 Programming Algorithm Requires
Variable VDD
The PIC16F8X uses an intelligent algorithm. The algo-
rithm calls for program verification at VDDmin. as well
as VDDmax. Verification at VDDmin. guarantees good
“erase margin”. Verification at VDDmax guarantees
good “program margin”.
The actual programming must be done with VDD in the
VDDP range (See Table 5-1).
VDDP =VCC range required during programming.
VDDmin. = minimum operating VDD spec for the part.
VDDmax.= maximum operating VDD spec for the part.
Programmers must verify the PIC16F8X at its specified
VDD max. and VDDmin levels. Since Microchip may
introduce future versions of the PIC16F8X with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: All BULK ERASE operations must take
place at 4.5 to 5.5 VDD range. Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
PIC16F8X
DS30262C-page 3-158 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC16F8X has five configuration bits. These bits
can be set (reads ‘0’) or left unchanged (reads ‘1’) to
select various device configurations.
3.1 Device ID Word
The device ID word for the PIC16F8XX is located at
2006h.
FIGURE 3-1: CONFIGURATION WORD BIT MAP FOR PIC16F83/CR83/F84/CR84/F84A
TABLE 3-1:
Device
Device ID Value
Dev Rev
PIC16F84A 00 0101 010 0 0000
PIC16F877 00 1001 101 0 0000
Bit
Number: 13 12 11 10 9 8 7 654321 0
PIC16F83/
F84/F84A CP CP CP CP CP CP CP CP CP CP PWRTE WDTE FOSC1 FOSC0
PIC16CR83/
CR84 CP CP CP CP CP CP DP CP CP CP PWRTE WDTE FOSC1 FOSC0
bit 4-13: CP, Code Protection Configuration Bits
1 = code protection off
0 = code protection on
bit 7: PIC16CR83/CR84 only
DP, Data Memory Code Protection Bit
1 = code protection off
0 = data memory is code protected
bit 3: PWRTE, Power Up Timer Enable Configuration Bit
1 = Power up timer disabled
0 = Power up timer enabled
bit 2: WDTE, WDT Enable Configuration Bits
1 = WDT enabled
0 = WDT disabled
bit 1-0 FOSC<1:0>, Oscillator Selection Configuration Bits
11: RC oscillator
10: HS oscillator
01: XT oscillator
00: LP oscillator
2000 Microchip Technology Inc. DS30262C-page 3-159
PIC16F8X
FIGURE 3-2: CONFIGURATION WORD FOR PIC16F877
CP1 CP0 BKBUG - WRT CPD LVP BODEN CP1 CP0 PWRTE WDTE F0SC1 F0SC0 Register: CONFIG
Address 2007h
bit13 bit0
bit 13-12:
bit 11: BKBUG: Background Debugger Mode (This bit documented as reserved in data sheet)
1 = Background debugger functions not enabled
0 = Background debugger functional.
bit 5-4: CP1:CP0: Flash Program Memory Code Protection bits (2)
11 = Code protection off
10 = 1F00h to 1FFFh code protected
01 = 1000h to 1FFFh code protected
00 = 0000h to 1FFFh code protected
bit 11: Reserved: Set to ‘1’ for normal operation
bit 10: Unimplemented: Read as ‘1’
bit 9: WRT: Flash Program Memory Write Enable
1 = Unprotected program memory may be written to by EECON control
0 = Unprotected program memory may not be written to by EECON control
bit 8: CPD: Data EE Memory Code Protection
1 = Code protection off
0 = Data EE memory code protected
bit 7: LVP: Low voltage programming Enable bit
1 = RB3/PGM pin has PGM function, low voltage programming enabled
0 = RB3 is digital I/O, HV on MCLR must be used for programming
bit 6: BODEN: Brown-out Reset Enable bit (1)
1 = BOR enabled
0 = BOR disabled
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC1:FOSC0: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
PIC16F8X
DS30262C-page 3-160 2000 Microchip Technology Inc.
4.0 CODE PROTECTION
For PIC16F8X devices, once code protection is
enabled, all program memory locations read all 0’s.
The ID locations and the configuration word read out in
an unscrambled fashion. Further programming is dis-
abled for the entire program memory as well as data
memory. It is possible to program the ID locations and
the configuration word.
4.1 Disabling Code-Protection
It is recommended that the following procedure be per-
formed before any other programming is attempted. It
is also possible to turn code protection off (code protect
bit = 1) using this procedure; however, all data within
the program memory and the data memory will be
erased when this procedure is executed, and thus,
the security of the data or code is not compro-
mised.
Procedure to disable code protect:
a) Execute load configuration (with a ‘1’ in bit 4,
code protect).
b) Increment to configuration word location
(0x2007)
c) Execute command (000001)
d) Execute command (000111)
e) Execute ‘Begin Programming’ (001000)
f) Wait 10 ms
g) Execute command (000001)
h) Execute command (000111)
4.2 Embedding Configuration Word and ID Information in the Hex File
TABLE 4-1: CONFIGURATION WORD
PIC16F83
To code protect: 0000000000XXXX
PIC16CR83
To code protect: 0000000000XXXX
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Specifically for the PIC16F8X, the EEPROM data memory should also be embedded in the hex file (see Section 5.1).
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
All memory Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled Read Unscrambled
All memory Read All 0’s for Program Memory,
Read All 1’s for Data Memory -
Write Disabled
Read Unscrambled, Data Memory -
Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled Read Unscrambled
2000 Microchip Technology Inc. DS30262C-page 3-161
PIC16F8X
PIC16CR84
To code protect: 0000000000XXXX
PIC16F84
To code protect: 0000000000XXXX
PIC16F84A
To code protect: 0000000000XXXX
PIC16F8XX
To code protect: 00X1XXXX00XXXX
Legend: X = Don’t care
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled Read Unscrambled
All memory Read All 0’s for Program Memory,
Read All 1’s for Data Memory -
Write Disabled
Read Unscrambled, Data Memory -
Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled Read Unscrambled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
All memory Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
All memory Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
Program Memory Segment R/W in Protected Mode R/W in Unprotected Mode
Configuration Word (0x2007) Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
All memory Read All 0’s, Write Disabled Read Unscrambled, Write Enabled
ID Locations [0x2000 : 0x2003] Read Unscrambled, Write Enabled Read Unscrambled, Write Enabled
PIC16F8X
DS30262C-page 3-162 2000 Microchip Technology Inc.
4.3 CHECKSUM COMPUTATION
4.3.1 CHECKSUM
Checksum is calculated by reading the contents of the
PIC16F8X memory locations and adding up the
opcodes up to the maximum user addressable location,
e.g., 0x1FF for the PIC16F8X. Any carry bits exceeding
16-bits are neglected. Finally, the configuration word
(appropriately masked) is added to the checksum.
Checksum computation for each member of the
PIC16F8X devices is shown in Table 4-2.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
TABLE 4-2: CHECKSUM COMPUTATION
Device
Code
Protect Checksum* Blank
Value
0x25E6 at 0
and max
address
PIC16F83 OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3FFF
CFGW & 0x3FFF + SUM_ID
0x3DFF
0x3E0E
0x09CD
0x09DC
PIC16CR83 OFF
ON
SUM[0x000:0x1FF] + CFGW & 0x3FFF
CFGW & 0x3FFF + SUM_ID
0x3DFF
0x3E0E
0x09CD
0x09DC
PIC16F84 OFF
ON
SUM[0x000:0x3FF] + CFGW & 0x3FFF
CFGW & 0x3FFF + SUM_ID
0x3BFF
0x3C0E
0x07CD
0x07DC
PIC16CR84 OFF
ON
SUM[0x000:0x3FF] + CFGW & 0x3FFF
CFGW & 0x3FFF + SUM_ID
0x3BFF
0x3C0E
0x07CD
0x07DC
PIC16F84A OFF
ON
SUM[0x000:0x3FF] + CFGW & 0x3FFF
CFGW & 0x3FFF + SUM_ID
0x3BFF
0x3C0E
0x07CD
0x07DC
PIC16F877 OFF SUM[0x0000:0x1FFF] + CFGW & 0x3BFF 0x1BFF 0xE7CD
0X1F00
–
0X1FFF
SUM[0x0000:0x1EFF] + CFGW & 0x3BFF +SUM_ID 0x28EE 0xDAA3
0x1000
–
0x1FFF
SUM[0x0000:0x0FFF] + CFGW & 0x3BFF + SUM_ID 0x27DE 0xD993
ALL CFGW & 0x3BFF + SUM_ID 0x27CE 0xF39C
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a to b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example, ID0 = 0x1, ID1 = 0x2, ID3 = 0x3, ID4 = 0x4, then SUM_ID = 0x1234
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
2000 Microchip Technology Inc. DS30262C-page 3-163
PIC16F8X
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
5.1 Embedding Data EEPROM Contents in Hex File
The programmer should be able to read data EEPROM information from a hex file and conversely (as an option) write
data EEPROM contents to a hex file along with program memory information and fuse information.
The 64 data memory locations are logically mapped starting at address 0x2100. The format for data memory storage
is one data byte per address location, LSB aligned.
TABLE 5-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY TEST MODE
Standard Operating Conditions
Operating Temperature: +10°C ≤ T
A ≤ +40°C, unless otherwise stated, (25°C is recommended)
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V, unless otherwise stated.
Paramet
er
No.
Sym. Characteristic Min. Typ. Max. Units Conditions/
Comments
VDDP Supply voltage during programming 4.5 5.0 5.5 V
VDDV Supply voltage during verify VDDmin VDDmax V Note 1
VIHH High voltage on MCLR for test mode
entry
12 14.0 V Note 2
IDDP Supply current (from VDD) during
program/verify
50 mA
IHH Supply current from VIHH (on MCLR) 200 µA
V
IH1 (RB6, RB7) input high level 0.8 VDD V Schmitt Trigger input
VIL1 (RB6, RB7) input low level MCLR
(test mode selection)
0.2 VDD V Schmitt Trigger input
P1 TvHHR M C L R rise time (VSS to VHH) for test
mode entry
8.0 µs
P2 Tset0 RB6, RB7 setup time (before pattern
setup time)
100 ns
P3 Tset1 Data in setup time before clock ↓ 100 ns
P4 Thld1 Data in hold time after clock ↓ 100 ns
P5 Tdly1 Data input not driven to next clock
input (delay required between com-
mand/data or command/command)
1.0 µs
P6 Tdly2 Delay between clock ↓ to clock ↑ of
next command or data
1.0 µs
P7 Tdly3 Clock to data out valid (during read
data)
80 ns
P8 Thld0 RB <7:6> hold time after MCLR ↑100 ns
- - Erase cycle time - - 10 ms
- - Program cycle time - - 10 ms
Note 1: Program must be verified at the minimum and maximum VDD limits for the part.
Note 2: VIHH must be greater than VDD + 4.5V to stay in programming/verify mode.
PIC16F8X
DS30262C-page 3-164 2000 Microchip Technology Inc.
FIGURE 5-1: LOAD DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND (PROGRAM/VERIFY)
}
}
}
}
100ns
min.
P4
P3
0
0
0
1µs min.
P5
1µs min.
P6
0
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR
P2
}
00
1µs min.
P5
1µs min.
P6
15
5432
1
6
5
Program/Verify Test Mode
0
43
0
100ns
P4
1
100ns
min.
P3
Reset
21
100ns
P8
VIHH
RB6
(CLOCK)
RB7
(DATA) 0
MCLR
RB7 = output RB7
input
P7
}
P2
}
}
0
000
00
11
12345 61
2
100ns
min
P3 P4
P6
1µs min. Next Command
P5
1µs min.
VIHH
MCLR
RB6
(CLOCK)
(DATA)
RB7
Reset
Program/Verify Test Mode
2000 Microchip Technology Inc. DS39025D-page 3-165
PIC16F8XX
This document includes the programming
specifications for the following devices:
1.0 PROGRAMMING THE
PIC16F8XX
The PIC16F8XX is programmed using a serial method.
The serial mode will allow the PIC16F8XX to be pro-
grammed while in the users system. This allows for
increased design flexibility. This programming specifi-
cation applies to PIC16F8XX devices in all packages.
PIC16F8XX devices may be programmed using a sin-
gle +5 volt supply (low voltage programming mode).
1.1 Hardware Requirements
The PIC16F8XX requires one programmable power
supply for VDD (4.5V to 5.5V) and a VPP of 12V to 14V
or VPP of (4.5V to 5.5V) when using low voltage In-Cir-
cuit Serial Programming™ (ICSP™). Both supplies
should have a minimum resolution of 0.25V.
1.2 Programming Mode
The programming mode for the PIC16F8XX allows pro-
gramming of user program memory, data memory, spe-
cial locations used for ID, and the configuration word.
Pin Diagram
• PIC16F870 • PIC16F874
• PIC16F871 • PIC16F876
• PIC16F872 • PIC16F877
•PIC16F873
PDIP, SOIC
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RD7/PSP7
RD6/PSP6
RD5/PSP5
RD4/PSP4
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
RD3/PSP3
RD2/PSP2
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3/VREF
RA4/T0CKI
RA5/AN4/SS
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
VDD
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RD0/PSP0
RD1/PSP1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
PIC16F877/874/871
PIC16F876/873/872/870
10
11
2
3
4
5
6
1
8
7
9
12
13
14 15
16
17
18
19
20
23
24
25
26
27
28
22
21
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3/VREF
RA4/T0CKI
RA5/AN4/SS
VSS
OSC1/CLKIN
OSC2/CLKOUT
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2
RC2/CCP1
RC3/SCK/SCL
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
VDD
VSS
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
PIN DESCRIPTIONS (DURING PROGRAMMING): PIC16F8XX
Pin Name
During Programming
Function Pin Type Pin Description
RB3 PGM I Low voltage ICSP programming input if
configuration bit equals 1
RB6 CLOCK I Clock input
RB7 DATA I/O Data input/output
MCLR VTEST MODE P* Program Mode Select
VDD VDD P Power Supply
VSS VSS P Ground
Legend: I = Input, O = Output, P = Power
*In the PIC16F8XX, the programming high voltage is internally generated. To activate the programming mode, high voltage needs
to be applied to MCLR input. Since the MCLR is used for a level source, this means that MCLR does not draw any significant current.
In-Circuit Serial Programming for PIC16F8XX FLASH MCUs
In-circuit Serial Programming (ICSP) is a trademark of Microchip Technology Inc.
PIC16F8XX
DS39025D-page 3-166 2000 Microchip Technology Inc.
2.0 PROGRAM MODE ENTRY
2.1 User Program Memory Map
The user memory space extends from 0x0000 to
0x1FFF (8K). In programming mode the program mem-
ory space extends from 0x0000 to 0x3FFF, with the first
half (0x0000-0x1FFF) being user program memory and
the second half (0x2000-0x3FFF) being configuration
memory. The PC will increment from 0x0000 to 0x1FFF
and wrap to 0x000, 0x2000 to 0x3FFF and wrap
around to 0x2000 (not to 0x0000). Once in configura-
tion memory, the highest bit of the PC stays a ‘1’, thus
always pointing to the configuration memory. The only
way to point to user program memory is to reset the
part and reenter program/verify mode as described in
Section 2.3.
In the configuration memory space, 0x2000-0x200F
are physically implemented. However, only locations
0x2000 through 0x2007 are available. Other locations
are reserved. Locations beyond 0x200F will physically
access user memory. (See Figure 2-1).
2.2 ID Locations
A user may store identification information (ID) in four
ID locations. The ID locations are mapped in [0x2000 :
0x2003]. It is recommended that the user use only the
four least significant bits of each ID location. In some
devices, the ID locations read-out in an unscrambled
fashion after code protection is enabled. For these
devices, it is recommended that ID location is written as
“11 1111 1000 bbbb” where ‘bbbb’ is ID information.
In other devices, the ID locations read out normally,
even after code protection. To understand how the
devices behave, refer to Table 4-1.
To understand the scrambling mechanism after code
protection, refer to Section 4.0.
2000 Microchip Technology Inc. DS39025D-page 3-167
PIC16F8XX
FIGURE 2-1: PROGRAM MEMORY MAPPING
2K
words
4K
words
8K
words
Implemented Implemented Implemented
Implemented Implemented Implemented
Implemented Implemented
Implemented Implemented
Reserved Implemented
Reserved Implemented
Implemented
Implemented
Reserved Reserved Reserved
Reserved Reserved Reserved
ID Location
ID Location
ID Location
ID Location
Reserved
Reserved
Device ID
Configuration Word
2000h
2001h
2002h
2003h
2004h
2005h
2006h
2007h
0h
1FFh
3FFh
400h
7FFh
800h
BFFh
C00h
FFFh
1000h
1FFFh
2008h
2100h
3FFFh
PIC16F8XX
DS39025D-page 3-168 2000 Microchip Technology Inc.
2.3 Program/Verify Mode
The program/verify mode is entered by holding pins
RB6 and RB7 low while raising MCLR pin from VIL to
VIHH (high voltage). In this mode, the state of the RB3
pin does not effect programming. Low-voltage ICSP
programming mode is entered by applying VDD to
MCLR and raising RB3 from VIL to VDD. Once in this
mode the user program memory and the configuration
memory can be accessed and programmed in serial
fashion. The mode of operation is serial, and the mem-
ory that is accessed is the user program memory. RB6
and RB7 are Schmitt Trigger Inputs in this mode.
The sequence that enters the device into the program-
ming/verify mode places all other logic into the reset
state (the MCLR pin was initially at VIL). This means
that all I/O are in the reset state (High impedance
inputs).
The normal sequence for programming is to use the
load data command to set a value to be written at the
selected address. Issue the begin programming com-
mand followed by read data command to verify, and
then increment the address.
A device reset will clear the PC and set the address to
0. The “increment address” command will increment
the PC. The “load configuration” command will se the
PC to 0x2000. The available commands are shown in
Ta bl e 2 - 1 .
2.3.1 LOW-VOLTAGE ICSP PROGRAMMING
MODE
When LVP bit is set to ‘1’, the low-voltage ICSP pro-
gramming entry is enabled. Since the LVP configura-
tion bit allows low voltage ICSP programming entry in
its erased state, an erased device will have the LVP bit
enabled at the factory. While LVP is ‘1’, RB3 is dedi-
cated to low voltage ICSP programming. Bring MCLR
to VDD and then RB3 to VDD to enter programming
mode. All other specifications for high-voltage ICSP™
apply.
To disable low voltage ICSP mode, the LVP bit must be
programmed to ‘0’. This must be done while entered
with high voltage entry mode (LVP bit= 1). RB3 is now
a general purpose I/O pin.
2.3.2 SERIAL PROGRAM/VERIFY OPERATION
The RB6 pin is used as a clock input pin, and the RB7
pin is used for entering command bits and data input/
output during serial operation. To input a command, the
clock pin (RB6) is cycled six times. Each command bit
is latched on the falling edge of the clock with the least
significant bit (LSB) of the command being input first.
The data on pin RB7 is required to have a minimum
setup and hold time (see AC/DC specifications) with
respect to the falling edge of the clock. Commands that
have data associated with them (read and load) are
specified to have a minimum delay of 1 µs between the
command and the data. After this delay, the clock pin is
cycled 16 times with the first cycle being a start bit and
the last cycle being a stop bit. Data is also input and
output LSB first.
Therefore, during a read operation the LSB will be
transmitted onto pin RB7 on the rising edge of the sec-
ond cycle, and during a load operation the LSB will be
latched on the falling edge of the second cycle. A min-
imum 1µs delay is also specified between consecutive
commands.
All commands are transmitted LSB first. Data words
are also transmitted LSB first. The data is transmitted
on the rising edge and latched on the falling edge of
the clock. To allow for decoding of commands and
reversal of data pin configuration, a time separation of
at least 1 µs is required between a command and a
data word (or another command).
The commands that are available are:
2.3.2.1 LOAD CONFIGURATION
After receiving this command, the program counter
(PC) will be set to 0x2000. By then applying 16 cycles
to the clock pin, the chip will load 14-bits in a “data
word,” as described above, to be programmed into the
configuration memory. A description of the memory
mapping schemes of the program memory for normal
operation and configuration mode operation is shown
in Figure 2-1. After the configuration memory is
entered, the only way to get back to the user program
memory is to exit the program/verify test mode by tak-
ing MCLR low (VIL).
Note: The OSC must not have 72 osc clocks
while the device MCLR is between VIL and
VIHH.
2000 Microchip Technology Inc. DS39025D-page 3-169
PIC16F8XX
2.3.2.2 LOAD DATA FOR PROGRAM MEMORY
After receiving this command, the chip will load in a
14-bit “data word” when 16 cycles are applied, as
described previously. A timing diagram for the load data
command is shown in Figure 5-1.
TABLE 2-1: COMMAND MAPPING FOR PIC16F84A/PIC16F877
Command Mapping (MSB … LSB) Data
Load Configuration XX00000, data (14), 0
Load Data for Program Memory XX00100, data (14), 0
Read Data from Program Memory XX01000, data (14), 0
Increment Address XX0110
Begin Erase Programming Cycle 001000
Begin Programming Only Cycle 011000
Load Data for Data Memory XX00110, data (14), 0
Read Data from Data Memory XX01010, data (14), 0
Bulk Erase Program Memory XX1001
Bulk Erase Data Memory XX1011
PIC16F8XX
DS39025D-page 3-170 2000 Microchip Technology Inc.
FIGURE 2-2: PROGRAM FLOW CHART - PIC16F8XX PROGRAM MEMORY
Start
Set VDD = VDDP
Program Cycle
Read Data
Command
Data Correct?
Report
Programming
Failure
All Locations
Done?
Verify all
Locations @
VDDMIN
Data Correct?
Verify all
Locations @
VDDMAX
Data Correct?
Done
Increment
Address
Command
Report Verify
Error @
VDDMIN
Report Verify
Error @
VDDMAX
Load Data
Command
Begin
Programming
Command
Wait tprog
PROGRAM CYCLE
No
No
No
No
2000 Microchip Technology Inc. DS39025D-page 3-171
PIC16F8XX
FIGURE 2-3: PROGRAM FLOW CHART - PIC16F8XX CONFIGURATION MEMORY
Program ID
Start
Load
Configuration
Data
Location? Program Cycle Read Data
Command
Data Correct?
Report
Programming
Failure
Increment
Address
Command
Address =
0x2004?
Increment
Address
Command
Increment
Address
Command
Increment
Address
Command
Program
Cycle
(Config. Word)
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Set VDD =
VDDMAX
Read Data
Command
Data Correct?
Report Program
Configutation
Word Error
Done
Ye s
No
No
Ye s
Ye sNo
No
Ye s
Ye s
No
PIC16F8XX
DS39025D-page 3-172 2000 Microchip Technology Inc.
2.3.2.3 LOAD DATA FOR DATA MEMORY
After receiving this command, the chip will load in a 14-
bit “data word” when 16 cycles are applied. However,
the data memory is only 8-bits wide, and thus only the
first 8-bits of data after the start bit will be programmed
into the data memory. It is still necessary to cycle the
clock the full 16 cycles in order to allow the internal cir-
cuitry to reset properly. The data memory contains 64
words. Only the lower 8-bits of the PC are decoded by
the data memory, and therefore if the PC is greater than
0x3F, it will wrap around and address a location within
the physically implemented memory. If the device is
code protected, the data is read as all zeros.
2.3.2.4 READ DATA FROM PROGRAM
MEMORY
After receiving this command, the chip will transmit
data bits out of the program memory (user or configu-
ration) currently accessed starting with the second ris-
ing edge of the clock input. The RB7 pin will go into
output mode on the second rising clock edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. A timing diagram of this command is
shown in Figure 5-2.
2.3.2.5 READ DATA FROM DATA MEMORY
After receiving this command, the chip will transmit
data bits out of the data memory starting with the sec-
ond rising edge of the clock input. The RB7 pin will go
into output mode on the second rising edge, and it will
revert back to input mode (hi-impedance) after the 16th
rising edge. As previously stated, the data memory is 8-
bits wide, and therefore, only the first 8-bits that are out-
put are actual data.
2.3.2.6 INCREMENT ADDRESS
The PC is incremented when this command is
received. A timing diagram of this command is shown
in Figure 5-3.
2.3.2.7 BEGIN ERASE/PROGRAM CYCLE
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes an erase before write. The user must allow for
both erase and programming cycle times for program-
ming to complete. No “end programming” command is
required.
2.3.2.8 BEGIN PROGRAMMING
A load command must be given before every begin
programming command. Programming of the appro-
priate memory (test program memory, user program
memory or data memory) will begin after this command
is received and decoded. An internal timing mechanism
executes a write. The user must allow for program cycle
time for programming to complete. No “end program-
ming” command is required.
This command is similar to the ERASE/PROGRAM
CYCLE command, except that a word erase is not
done. It is recommended that a bulk erase be per-
formed before starting a series of programming only
cycles.
2.3.2.9 BULK ERASE PROGRAM MEMORY
After this command is performed, the next program
command will erase the entire program memory.
To perform a bulk erase of the program memory, the fol-
lowing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase Program Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
If the address is pointing to the test program memory
(0x2000 - 0x200F), then both the user memory and the
test memory will be erased. The configuration word will
not be erased, even if the address is pointing to location
0x2007.
2.3.2.10 BULK ERASE DATA MEMORY
To perform a bulk erase of the data memory, the follow-
ing sequence must be performed.
1. Do a “Load Data All 1’s” command.
2. Do a “Bulk Erase Data Memory” command.
3. Do a “Begin Programming” command.
4. Wait 10 ms to complete bulk erase.
Note: If the device is code-protected, the BULK
ERASE command will not work.
Note: All BULK ERASE operations must take
place at 4.5 to 5.5 VDD range.
2000 Microchip Technology Inc. DS39025D-page 3-173
PIC16F8XX
2.4 Programming Algorithm Requires
Variable VDD
The PIC16F8XX uses an intelligent algorithm. The
algorithm calls for program verification at VDDmin. as
well as VDDmax. Verification at VDDmin. guarantees
good “erase margin”. Verification at VDDmax guaran-
tees good “program margin”.
The actual programming must be done with VDD in the
VDDP range (See Table 5-1).
VDDP =VCC range required during programming.
VDDmin. = minimum operating VDD spec for the part.
VDDmax.= maximum operating VDD spec for the part.
Programmers must verify the PIC16F8XX at its speci-
fied VDD max. and VDDmin levels. Since Microchip may
introduce future versions of the PIC16F8XX with a
broader VDD range, it is best that these levels are user
selectable (defaults are ok).
Note: Any programmer not meeting these
requirements may only be classified as
“prototype” or “development” programmer
but not a “production” quality programmer.
PIC16F8XX
DS39025D-page 3-174 2000 Microchip Technology Inc.
3.0 CONFIGURATION WORD
The PIC16F8XX has several configuration bits. These
bits can be set (reads ‘0’) or left unchanged (reads ‘1’)
to select various device configurations.
3.1 Device ID Word
The device ID word for the PIC16F8XX is located at
2006h.
FIGURE 3-1: CONFIGURATION WORD FOR PIC16F873/874/876/877
TABLE 3-1: DEVICE ID VALUE
Device
Device ID Value
Dev Rev
PIC16F870 00 1101 000 x xxxx
PIC16F871 00 1101 001 x xxxx
PIC16F872 00 1000 111 x xxxx
PIC16F873 00 1001 011 x xxxx
PIC16F874 00 1001 001 x xxxx
PIC16F876 00 1001 111 x xxxx
PIC16F877 00 1001 101 x xxxx
CP1 CP0 RESV - WRT CPD LVP BODEN CP1 CP0 PWRTE WDTE F0SC1 F0SC0 Register: CONFIG
Address 2007h
bit13 bit0
bit 13-12:
bit 11: Reserved: Set to ‘1’ for normal operation
bit 5-4: CP1:CP0: Flash Program Memory Code Protection bits (2)
4K Devices:
11 = Code protection off
10 = not supported
01 = not supported
00 = 0000h to 0FFFh code protected
8K Devices:
11 = Code protection off
10 = 1F00h to 1FFFh code protected
01 = 1000h to 1FFFh code protected
00 = 0000h to 1FFFh code protected
bit 11: Reserved: Set to ‘1’ for normal operation
bit 10: Unimplemented: Read as ‘1’
bit 9: WRT: Flash Program Memory Write Enable
1 = Unprotected program memory may be written to by EECON control
0 = Unprotected program memory may not be written to by EECON control
bit 8: CPD: Data EE Memory Code Protection
1 = Code protection off
0 = Data EE memory code protected
bit 7: LVP: Low voltage programming Enable bit
1 = RB3/PGM pin has PGM function, low voltage programming enabled
0 = RB3 is digital I/O, HV on MCLR must be used for programming
bit 6: BODEN: Brown-out Reset Enable bit (1)
1 = BOR enabled
0 = BOR disabled
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC1:FOSC0: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
2000 Microchip Technology Inc. DS39025D-page 3-175
PIC16F8XX
FIGURE 3-2: CONFIGURATION WORD FOR PIC16F870/871/872
CP1 CP0 RESV - WRT CPD LVP BODEN CP1 CP0 PWRTE WDTE F0SC1 F0SC0 Register: CONFIG
Address 2007h
bit13 bit0
bit 13-12:
bit 5-4: CP1:CP0: Flash Program Memory Code Protection bits (2)
11 = Code protection off
10 = not supported
01 = not supported
00 = 0000h to 07FFh code protected
bit 11: Reserved: Set to ‘1’ for normal operation
bit 10: Unimplemented: Read as ‘1’
bit 9: WRT: Flash Program Memory Write Enable
1 = Unprotected program memory may be written to by EECON control
0 = Unprotected program memory may not be written to by EECON control
bit 8: CPD: Data EE Memory Code Protection
1 = Code protection off
0 = Data EE memory code protected
bit 7: LVP: Low voltage programming Enable bit
1 = RB3/PGM pin has PGM function, low voltage programming enabled
0 = RB3 is digital I/O, HV on MCLR must be used for programming
bit 6: BODEN: Brown-out Reset Enable bit (1)
1 = BOR enabled
0 = BOR disabled
bit 3: PWRTE: Power-up Timer Enable bit (1)
1 = PWRT disabled
0 = PWRT enabled
bit 2: WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
bit 1-0: FOSC1:FOSC0: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
PIC16F8XX
DS39025D-page 3-176 2000 Microchip Technology Inc.
4.0 CODE PROTECTION
For PIC16F8XX devices, once code protection is
enabled, all program memory locations read all 0’s.
The ID locations and the configuration word read out in
an unscrambled fashion. Further programming is dis-
abled for the entire program memory as well as data
memory. It is possible to program the ID locations and
the configuration word.
4.1 Disabling Code-Protection
It is recommended that the following procedure be per-
formed before any other programming is attempted. It
is also possible to turn code protection off (code protect
bit = 1) using this procedure; however, all data within
the program memory and the data memory will be
erased when this procedure is executed, and thus,
the security of the data or code is not compro-
mised.
Procedure to disable code protect:
a) Execute load configuration (with a ‘1’ in bit 13-4,
code protect).
b) Increment to configuration word location
(0x2007)
c) Execute command (000001)
d) Execute command (000111)
e) Execute ‘Begin Programming’ (001000)
f) Wait 12 ms
g) Execute command (000001)
h) Execute command (000111)
4.2 Embedding Configuration Word and ID Information in the Hex File
To allow portability of code, the programmer is required to read the configuration word and ID locations from the hex
file when loading the hex file. If configuration word information was not present in the hex file then a simple warning
message may be issued. Similarly, while saving a hex file, configuration word and ID information must be included.
An option to not include this information may be provided.
Specifically for the PIC16F8XX, the EEPROM data memory should also be embedded in the hex file (see
Section 5.1).
Microchip Technology Inc. feels strongly that this feature is important for the benefit of the end customer.
2000 Microchip Technology Inc. DS39025D-page 3-177
PIC16F8XX
4.3 CHECKSUM COMPUTATION
4.3.1 CHECKSUM
Checksum is calculated by reading the contents of the
PIC16F8XX memory locations and adding up the
opcodes up to the maximum user addressable location,
e.g., 0x1FF for the PIC16F8XX. Any carry bits exceed-
ing 16-bits are neglected. Finally, the configuration
word (appropriately masked) is added to the check-
sum. Checksum computation for each member of the
PIC16F8XX devices is shown in Table 4-1.
The checksum is calculated by summing the following:
•The contents of all program memory locations
•The configuration word, appropriately masked
•Masked ID locations (when applicable)
The least significant 16 bits of this sum is the check-
sum.
The following table describes how to calculate the
checksum for each device. Note that the checksum cal-
culation differs depending on the code protect setting.
Since the program memory locations read out differ-
ently depending on the code protect setting, the table
describes how to manipulate the actual program mem-
ory values to simulate the values that would be read
from a protected device. When calculating a checksum
by reading a device, the entire program memory can
simply be read and summed. The configuration word
and ID locations can always be read.
Note that some older devices have an additional value
added in the checksum. This is to maintain compatibil-
ity with older device programmer checksums.
PIC16F8XX
DS39025D-page 3-178 2000 Microchip Technology Inc.
TABLE 4-1: CHECKSUM COMPUTATION
Device Code
Protect Checksum* Blank”V
alue
0x25E6 at 0
and max
address
PIC16F870 OFF SUM[0x0000:0x07FFF] + CFGW & 0x3BFF 0x33FF 0xFFCD
ALL CFGW & 0x3BFF + SUM_ID 0x3FCE 0x0B9C
PIC16F871 OFF SUM[0x0000:0x07FFF] + CFGW & 0x3BFF 0x33FF 0xFFCD
ALL CFGW & 0x3BFF + SUM_ID 0x3FCE 0x0B9C
PIC16F872 OFF SUM[0x0000:0x07FFF] + CFGW & 0x3BFF 0x33FF 0xFFCD
ALL CFGW & 0x3BFF + SUM_ID 0x3FCE 0x0B9C
PIC16F873 OFF SUM[0x0000:0x0FFF] + CFGW & 0x3BFF 0x2BFF 0xF7CD
0x0F00 : 0xFFF SUM[0x0000:0x0EFF] + CFGW & 0x3BFF +SUM_ID 0x48EE 0xFAA3
0x0800 : 0xFFF SUM[0x0000:0x07FF] + CFGW & 0x3BFF + SUM_ID 0x3FDE 0xF193
ALL CFGW & 0x3BFF + SUM_ID 0x37CE 0x039C
PIC16F874 OFF SUM[0x0000:0x0FFF] + CFGW & 0x3BFF 0x2BFF 0xF7CD
0x0F00 : 0xFFF SUM[0x0000:0x0EFF] + CFGW & 0x3BFF +SUM_ID 0x48EE 0xFAA3
0x0800 : 0xFFF SUM[0x0000:0x07FF] + CFGW & 0x3BFF + SUM_ID 0x3FDE 0xF193
ALL CFGW & 0x3BFF + SUM_ID 0x37CE 0x039C
PIC16F876 OFF SUM[0x0000:0x1FFF] + CFGW & 0x3BFF 0x1BFF 0xE7CD
0x1F00 : 0x1FFF SUM[0x0000:0x1EFF] + CFGW & 0x3BFF +SUM_ID 0x28EE 0xDAA3
0x1000 : 0x1FFF SUM[0x0000:0x0FFF] + CFGW & 0x3BFF + SUM_ID 0x27DE 0xD993
ALL CFGW & 0x3BFF + SUM_ID 0x27CE 0xF39C
PIC16F877 OFF SUM[0x0000:0x1FFF] + CFGW & 0x3BFF 0x1BFF 0xE7CD
0x1F00 : 0x1FFF SUM[0x0000:0x1EFF] + CFGW & 0x3BFF +SUM_ID 0x28EE 0xDAA3
0x1000 : 0x1FFF SUM[0x0000:0x0FFF] + CFGW & 0x3BFF + SUM_ID 0x27DE 0xD993
ALL CFGW & 0x3BFF + SUM_ID 0x27CE 0xF39C
Legend: CFGW = Configuration Word
SUM[a:b] = [Sum of locations a to b inclusive]
SUM_ID = ID locations masked by 0xF then made into a 16-bit value with ID0 as the most significant nibble.
For example, ID0 = 0x1, ID1 = 0x2, ID3 = 0x3, ID4 = 0x4, then SUM_ID = 0x1234
*Checksum = [Sum of all the individual expressions] MODULO [0xFFFF]
+ = Addition
& = Bitwise AND
2000 Microchip Technology Inc. DS39025D-page 3-179
PIC16F8XX
5.0 PROGRAM/VERIFY MODE ELECTRICAL CHARACTERISTICS
5.1 Embedding Data EEPROM Contents in Hex File
The programmer should be able to read data EEPROM information from a hex file and conversely (as an option) write
data EEPROM contents to a hex file along with program memory information and fuse information.
The 256 data memory locations are logically mapped starting at address 0x2100. The format for data memory storage
is one data byte per address location, LSB aligned.
TABLE 5-1: AC/DC CHARACTERISTICS
TIMING REQUIREMENTS FOR PROGRAM/VERIFY MODE
Standard Operating Conditions (unless otherwise stated)
Operating Temperature: 0°C ≤ TA ≤ +70°C
Operating Voltage: 4.5V ≤ VDD ≤ 5.5V
Characteristics Sym Min Typ Max Units Conditions/Comments
General
VDD level for word operations, program
memory VDD 2.0 5.5 V
VDD level for word operations, data mem-
ory VDD 2.0 5.5 V
VDD level for bulk erase/write operations,
program and data memory VDD 4.5 5.5 V
High voltage on MCLR for
high-voltage programming entry VIHH VDD + 3.5 13.5 V
Voltage on MCLR for
low-voltage programming entry
VIH 4.5 5.5 V
MCLR rise time (VSS to VHH) for test
mode entry
tVHHR 1.0 µs
(RB6, RB7) input high level VIH1 0.8VDD V Schmitt Trigger input
(RB6, RB7) input low level VIL1 0.2VDD V Schmitt Trigger input
RB<7:4> setup time before MCLR↑
(test mode selection pattern setup time)
tset0 100 ns
RB<7:4> hold time after MCLR↑
(test mode selection pattern setup time)
thld0 5 µs
Serial Program/Verify
Data in setup time before clock↓tset1100 ns
Data in hold time after clock↓thld1100 ns
Data input not driven to next clock input
(delay required between command/data or
command/command)
tdly11.0 µs
Delay between clock↓ to clock↑ of next
command or data
tdly2 1.0 µs
Clock↑ to data out valid (during read data) tdly3 80 ns
Erase cycle time tera 2 5 ms
Programming cycle time tprog 2 5 ms
PIC16F8XX
DS39025D-page 3-180 2000 Microchip Technology Inc.
FIGURE 5-1: LOAD DATA COMMAND HIGH-VOLTAGE MODE (PROGRAM/VERIFY)
FIGURE 5-2: READ DATA COMMAND HIGH-VOLTAGE MODE (PROGRAM/VERIFY)
FIGURE 5-3: INCREMENT ADDRESS COMMAND HIGH-VOLTAGE MODE (PROGRAM/VERIFY)
MCLR
VIHH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tset1
thld1
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
100ns min.
1µs min.
tdly2
12 3 4 5 6
0100XX
12 3 4 5 15
16
strt_bit stp_bit
100ns min.
}
thld0
}
}
}
MCLR
VIHH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
0010XX
12 3 4 5 15
16
100ns min.
}
}
tdly3
RB7 = input RB7 = output
RB7
input
thld0
strt_bit stp_bit
MCLR
VIHH
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
011 XX
12
100ns min.
}
}
X0
0
Next Command
2000 Microchip Technology Inc. DS39025D-page 3-181
PIC16F8XX
FIGURE 5-4: LOAD DATA COMMAND LOW-VOLTAGE MODE (PROGRAM/VERIFY)
FIGURE 5-5: READ DATA COMMAND LOW-VOLTAGE MODE (PROGRAM/VERIFY)
FIGURE 5-6: INCREMENT ADDRESS COMMAND LOW-VOLTAGE MODE (PROGRAM/VERIFY)
MCLR
VIH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tset1
thld1
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
100ns min.
1µs min.
tdly2
12 3 4 5 6
0100XX
12 3 4 5 15
16
strt_bit stp_bit
100ns min.
}
thld0
}
}
}
RB3
MCLR
VIH
tset0
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
0010XX
12 3 4 5 15
16
100ns min.
}
}
tdly3
RB7 = input RB7 = output
RB7
input
thld0
strt_bit stp_bit
RB3
MCLR
VIH
RB6
(CLOCK)
RB7
(DATA)
Reset
tdly1
1µs min.
Program/Verify Test Mode
tset1
thld1
1µs min.
tdly2
12 3 4 56
011 XX
12
100ns min.
}
}
X0
0
Next Command
RB3
PIC16F8XX
DS39025D-page 3-182 2000 Microchip Technology Inc.
NOTES:
DS30277C-page 4-ii 2000 Microchip Technology Inc.
2000 Microchip Technology Inc. DS00656B-page 4-1
AN656
INTRODUCTION
Many embedded control applications, where sensor
offsets, slopes and configuration information are mea-
sured and stored, require a calibration step. Tradition-
ally, potentiometers or Serial EEPROM devices are
used to set up and store this calibration information.
This application note will show how to construct a pro-
gramming jig that will receive calibration parameters
from the application mid-range PICmicro® microcon-
trollers (MCU) and program this information into the
application baseline PICmicro MCU using the In-Circuit
Serial Programming (ICSP) protocol. This method uses
the PIC16CXXX In-Circuit Serial Programming algo-
rithm of the 14-bit core microcontrollers.
PROGRAMMING FIXTURE
A programming fixture is needed to assist with the self
programming operation. This is typically a small re-
usable module that plugs into the application PCB
being calibrated. Only five pin connections are needed
and this programming fixture can draw its power from
the application PCB to simplify the connections.
FIGURE 1:
Author: John Day
Microchip Technology Inc.
PIC16CXXX
Sensor(s)
Application I/O
To Application Input(s)
RAX
RBX
MCLR/VPP
VDD
VSS
RB7
RB6
+5V
10k
Customer Application PCB
VPP
VDD
VSS
RB7
RB6
Calibration Programming Jig
+13V VPP
Generator
PIC16C58
+5V +5V
VDD
GND_ON
VPP_ON VSS
MCLR
RB7
RB6
RB5
RB4 RB3
RB2
RB1
RC osc
Optional PC Connection
1k
Wait
Done
In-Circuit Serial Programming™ (ICSP™) of Calibration Parameters
Using a PICmicro® Microcontroller
AN656
DS00656B-page 4-2 2000 Microchip Technology Inc.
Electrical Interface
There are a total of five electrical connections needed
between the application PIC16CXXX microcontroller
and the programming jig:
•MCLR/VPP - High voltage pin used to place appli-
cation PIC16CXXX into programming mode
•VDD - +5 volt power supply connection to the
application PIC16CXXX
•VSS - Ground power supply connection to the
application PIC16CXXX
•RB6 - PORTB, bit6 connection to application
PIC16CXXX used to clock programming data
•RB7 - PORTB, bit7 connection to application
PIC16CXXX used to send programming data
This programming jig is intended to grab power from
the application power supply through the VDD connec-
tion. The programming jig will require 100 mA of peak
current during programming. The application will need
to set RB6 and RB7 as inputs, which means external
devices cannot drive these lines. The calibration data
will be sent to the programming jig by the application
PIC16CXXX through RB6 and RB7. The programming
jig will later use these lines to clock the calibration data
into the application PIC16CXXX.
Programming Issues
The PIC16CXXX programming specification suggests
verification of program memory at both Maximum and
Minimum VDD for each device. This is done to ensure
proper programming margins and to detect (and reject)
any improperly programmed devices. All production
quality programmers vary VDD from VDDmin to VDDmax
after programming and verify the device under each of
these conditions.
Since both the application voltage and it’s tolerances
are known, it is not necessary to verify the PIC16CXXX
calibration parameters at the device VDDmax and
VDDmin. It is only necessary to verify at the application
power supply Max and Min voltages. This application
note shows the nominal (+5V) verification routine and
hardware. If the power supply is a regulated +5V, this
is adequate and no additional hardware or software is
needed. If the application power supply is not regulated
(such as a battery powered or poorly regulated system)
it is important to complete a VDDmin and VDDmax veri-
fication cycle following the +5V verification cycle. See
programming specifications for more details on VDD
verification procedures.
•PIC16C5X Programming Specifications -
DS30190
•PIC16C55X Programming Specifications -
DS30261
•PIC16C6X/7X/9XX Programming Specifications -
DS30228
•PIC16C84 Programming Specifications -
DS30189
The calibration programming and initial verification
MUST occur at +5V. If the application is intended to run
at lower (or higher voltages), a second verification pass
must be added where those voltages are applied to
VDD and the device is verified.
Note: The designer must consider environmental
conditions, voltage ranges, and aging
issues when determining VDD min/max
verification levels. Please refer to the pro-
gramming specification for the application
device.
2000 Microchip Technology Inc. DS00656B-page 4-3
AN656
Communication Format (Application
Microcontroller to Programming Jig)
Unused program memory, in the application
PIC16CXXX, is left unprogrammed as all 1s; therefore
the unprogrammed program memory for the calibration
look-up table would contain 3FFF (hex). This is inter-
preted as an “ADDLW FF”. The application microcon-
troller simply needs one “RETLW FF” instruction at the
end of the space allocated in program memory for the
calibration parameter look-up table. When the applica-
tion microcontroller is powered up, it will receive a “FFh”
for each calibration parameter that is looked up; there-
fore, it can detect that it is uncalibrated and jump to the
calibration code.
Once the calibration constants are calculated by the
application PICmicro MCU, they need to be communi-
cated to the (PIC16C58A based) programming jig. This
is accomplished through the RB6 and RB7 lines. The
format is a simple synchronous clock and data format
as shown in Figure 2.
A pull-down on the clock line is used to hold it low. The
application microcontroller needs to send the high and
low bytes of the target start address of the calibration
constants to the calibration jig. Next, the data bytes are
sent followed by a checksum of the entire data transfer
as shown in Figure 1.
Once the data transfer is complete, the checksum is
verified by the programming jig and the data printed at
9600 baud, 8-bits, no parity, 1 stop bit through RB3. A
connection to this pin is optional. Next the programming
jig applies +13V, programs and verifies the application
PIC16CXXX calibration parameters.
FIGURE 2:
FIGURE 1:
RB6
RB7 CALbit7 CALbit6 CALbit5 CALbit4 CALbit3 CALbit2 CALbit1 CALbit0
AddrH AddrL Data 0 Data 1 Data N CKSUM
AN656
DS00656B-page 4-4 2000 Microchip Technology Inc.
LED Operation
When the programming jig is waiting for communication
from the application PICmicro MCU, both LEDs are
OFF. Once a valid data stream is received (with at least
one calibration byte and a correct checksum) the
WORK LED is lit while the calibration parameters are
printed through the optional RB3 port. Next, the DONE
LED is lit to indicate that these parameters are being
programmed and verified by the programming jig. Once
the programming is finished, the WORK LED is extin-
guished and the DONE LED remains lit. If any param-
eters fail programming, the DONE LED is extinguished;
therefore both LEDs would remain off.
FIGURE 3: ISP CALIBRATION JIG PROGRAMMER SCHEMATIC
T0CKI
VSS VDD
VCC VCC
VPP
VCC
VCC
VCC
VPP
VIN
VREF
VCC
VCC VCC
2000 Microchip Technology Inc. DS00656B-page 4-5
AN656
Code Protection
Selection of the code protection configuration bits on
PIC16CXXX microcontrollers prevents further pro-
gramming of the program memory array. This would
prevent writing self calibration parameters if the device
is code protected prior to calibration. There are two
ways to address this issue:
1. Do not code protect the device when program-
ming it with the programmer. Add additional
code (See the PIC16C6X/7X programming
Spec) to the ISPPRGM.ASM to program the code
protection bit after complete verification of the
calibration parameters
2. Only code protect 1/2 or 3/4 of the program
memory with the programmer. Place the calibra-
tion constants into the unprotected part of pro-
gram memory.
Software Routines
There are two source code files needed for this appli-
cation note:
1. ISPTEST.ASM (Appendix A) Contains the source
code for the application PIC16CXXX, sets up the cali-
bration look-up table and implements the communica-
tion protocol to the programming jig.
2. ISPPRGM.ASM (Appendix B) Source code for a
PIC16C58A to implement the programming jig. This
waits for and receives the calibration parameters from
the application PIC16CXXX, places it into program-
ming mode and programs/verifies each calibration
word.
CONCLUSION
Typically, calibration information about a system is
stored in EEPROM. For calibration data that does not
change over time, the In-circuit Serial Programming
capability of the PIC16CXXX devices provide a simple,
cost effective solution to an external EEPROM. This
method not only decreases the cost of a design, but
also reduces the complexity and possible failure points
of the application.
TABLE 1: PARTS LIST FOR PIC16CXXX ISP CALIBRATION JIG
Bill of Material
Item Quantity Reference Part
1 2 C1,C2 15 pF
2 1 C3 620 pF
3 1 C4 0.1 mF
4 2 C5,C6 220 mF
52D1,D2 LED
6 1 E1 PIC16C58
7 1 E2 LM78S40
8 1 J1 CON5
9 1 L1 270 mH
10 2 Q1,Q2 2N2222
11 2 Q3,Q4 2N2907
12 5 R1,R2,R3,R4,R15 1k
13 4 R5,R6,R12,R14 10k
14 2 R7,R8 270
15 1 R9 180
16 1 R10 23.7k
17 1 R11 2.49k
18 1 R13 2.2k
19 1 Y1 4.0 MHz
AN656
DS00656B-page 4-6 2000 Microchip Technology Inc.
APPENDIX A:
MPASM 01.40.01 Intermediate ISPPRGM.ASM 3-31-1997 10:57:03 PAGE 1
LOC OBJECT CODE LINE SOURCE TEXT
VALUE
00001 ; Filename: ISPPRGM.ASM
00002 ; **********************************************
00003 ; * Author: John Day *
00004 ; * Sr. Field Applications Engineer *
00005 ; * Microchip Technology *
00006 ; * Revision: 1.0 *
00007 ; * Date August 25, 1995 *
00008 ; * Part: PIC16C58 *
00009 ; * Compiled using MPASM V1.40 *
00010 ; **********************************************
00011 ; * Include files: *
00012 ; * P16C5X.ASM *
00013 ; **********************************************
00014 ; * Fuses: OSC: XT (4.0 Mhz xtal) *
00015 ; * WDT: OFF *
00016 ; * CP: OFF *
00017
;*********************************************************************************
00018 ; This program is intended to be used as a self programmer
00019 ; to store calibration constants into a lookup table
00020 ; within the main system processor. A 4 Mhz crystal
00021 ; is needed and an optional 9600 baud seiral port will
00022 ; display the parameters to be programmed.
00023 ;
;*********************************************************************************
00024 ; * Program Memory: *
00025 ; * Words - communication with test jig *
00026 ; * 17 Words - calibration look-up table (16 bytes of data) *
00027 ; * 13 Words - Test Code to generate Calibration Constants *
00028 ; * RAM memory: *
00029 ; * 64 Bytes - Store up to 64 bytes of calibration constant *
00030 ; * 9 Bytes - Store 9 bytes of temp variables (reused) *
00031 ;
;****************************************************************************
00032
00033 list p=16C58A
00034 include <p16C5x.inc>
00001 LIST
00002 ; P16C5X.INC Standard Hdr File, Version 3.30 Microchip Technology, Inc.
00224 LIST
0FFF 0FF9 00035 __CONFIG _CP_OFF&_WDT_OFF&_XT_OSC
00036
00037 ; ************************************
00038 ; * Port A (RA0-RA4) bit definitions *
00039 ; ************************************
00040 ; No PORT A pins are used in this design
00041
00042 ; ************************************
00043 ; * Port B (RB0-RB7) bit definitions *
00044 ; ************************************
00000006 00045 ISPCLOCK EQU 6 ; Clock line for ISP and parameter comm
00000007 00046 ISPDATA EQU 7 ; Data line for ISP and parameter comm
00000005 00047 VPPON EQU 5 ; Apply +13V VPP voltage to MCLR (test mode)
00000004 00048 GNDON EQU 4 ; Apply +0V (gnd) voltage to MCLR (reset)
00000003 00049 SEROUT EQU 3 ; Optional RS-232 TX output (needs 12V driver)
00000002 00050 DONELED EQU 2 ; Turns on LED when done sucessfully program
00000001 00051 WORKLED EQU 1 ; On during programming, off when done
00052 ; RB0 is not used in this design
00053
2000 Microchip Technology Inc. DS00656B-page 4-7
AN656
00054 ; *************************************************
00055 ; * RAM register definition: *
00056 ; * 07h - 0Fh - used for internal counters, vars *
00057 ; * 10h - 7Fh - 64 bytes for cal param storage *
00058 ; *************************************************
00059 ; ***
00060 ; *** The following VARS are used during ISP programming:
00061 ; ***
00000007 00062 HIADDR EQU 07h ; High address of CAL params to be stored
00000008 00063 LOADDR EQU 08h ; Low address of CAL params to be stored
00000007 00064 HIDATA EQU 07h ; High byte of data to be sent via ISP
00000008 00065 LODATA EQU 08h ; Low byte of data to be sent via ISP
00000009 00066 HIBYTE EQU 09h ; High byte of data received via ISP
0000000A 00067 LOBYTE EQU 0Ah ; Low byte of data received via ISP
0000000B 00068 PULSECNT EQU 0Bh ; Number of times PIC has been pulse programmed
0000000C 00069 TEMPCOUNT EQU 0Ch ; TEMP var used in counters
0000000D 00070 TEMP EQU 0Dh ; TEMP var used throughout program
00071 ; ***
00072 ; *** The following VARS are used to receive and store CAL params:
00073 ; ***
00000007 00074 COUNT EQU 07h ; Counter var used to receive cal params
00000008 00075 TEMP1 EQU 08h ; TEMP var used for RS-232 comm
00000009 00076 DATAREG EQU 09h ; Data register used for RS-232 comm
0000000A 00077 CSUMTOTAL EQU 0Ah ; Running total of checksum (addr + data)
0000000B 00078 TIMEHIGH EQU 0Bh ; Count how long CLOCK line is high
0000000C 00079 TIMELOW EQU 0Ch ; Count how long CLOCK line is low
0000000E 00080 ADDRPTR EQU 0Eh ; Pointer to next byte of CAL storage
0000000F 00081 BYTECOUNT EQU 0Fh ; Number of CAL bytes received
00082
00083 ; *************************************
00084 ; * Various constants used in program *
00085 ; *************************************
00000001 00086 DATISPOUT EQU b’00000001’ ; tris settings for ISP data out
00000081 00087 DATISPIN EQU b’10000001’ ; tris settings for ISP data in
00000006 00088 CMDISPCNT EQU 6 ; Number of bits for ISP command
00000010 00089 STARTCALBYTE EQU 10h ; Address in RAM where CAL byte data stored
00000007 00090 VFYYES EQU PA2 ; Flag bit enables verification (STATUS)
00000006 00091 CMDISPINCRADDR EQU b’00000110’ ; ISP Pattern to increment address
00000008 00092 CMDISPPGMSTART EQU b’00001000’ ; ISP Pattern to start programming
0000000E 00093 CMDISPPGMEND EQU b’00001110’ ; ISP Pattern to end programming
00000002 00094 CMDISPLOAD EQU b’00000010’ ; ISP Pattern to load data for program
00000004 00095 CMDISPREAD EQU b’00000100’ ; ISP Pattern to read data for verify
00000034 00096 UPPER6BITS EQU 034h ; Upper 6 bits for retlw instruction
00097
00098 ; *************************************
00099 ; * delaybit macro *
00100 ; * Delays for 104 uS (at 4 Mhz clock)*
00101 ; * for 9600 baud communications *
00102 ; * RAM used: COUNT *
00103 ; *************************************
00104 delaybit macro
00105 local dlylabels
00106 ; 9600 baud, 8 bit, no parity, 104 us per bit, 52 uS per half bit
00107 ; (8) shift/usage + (2) setup + (1) nop + (3 * 31) literal = (104) 4Mhz
00108 movlw .31 ; place 31 decimal literal into count
00109 movwf COUNT ; Initialize COUNT with loop count
00110 nop ; Add one cycle delay
00111 dlylabels
00112 decfsz COUNT,F ; Decrement count until done
00113 goto dlylabels ; Not done delaying - go back!
00114 ENDM ; Done with Macro
00115
00116 ; ************************************************
00117 ; * addrtofsr macro *
00118 ; * Converts logical, continuous address 10h-4Fh *
00119 ; * to FSR address as follows for access to (4) *
AN656
DS00656B-page 4-8 2000 Microchip Technology Inc.
00120 ; * banks of file registers in PIC16C58: *
00121 ; * Logical Address FSR Value *
00122 ; * 10h-1Fh 10h-1Fh *
00123 ; * 20h-2Fh 30h-3Fh *
00124 ; * 30h-3Fh 50h-5Fh *
00125 ; * 40h-4Fh 70h-7Fh *
00126 ; * Variable Passed: Logical Address *
00127 ; * RAM used: FSR *
00128 ; * W *
00129 ; ************************************************
00130 addrtofsr macro TESTADDR
00131 movlw STARTCALBYTE ; Place base address into W
00132 subwf TESTADDR,w ; Offset by STARTCALBYTE
00133 movwf FSR ; Place into FSR
00134 btfsc FSR,5 ; Shift bits 4,5 to 5,6
00135 bsf FSR,6
00136 bcf FSR,5
00137 btfsc FSR,4
00138 bsf FSR,5
00139 bsf FSR,4
00140 endm
00141
00142
00143 ; **************************************
00144 ; * The PC starts at the END of memory *
00145 ; **************************************
07FF 00146 ORG 7FFh
Message[306]: Crossing page boundary -- ensure page bits are set.
07FF 0A00 00147 goto start
00148
00149 ; **************************************
00150 ; * Start of CAL param read routine *
00151 ; **************************************
0000 00152 ORG 0h
0000 00153 start
0000 0C0A 00154 movlw b’00001010’ ; Serial OFF, LEDS OFF, VPP OFF
0001 0026 00155 movwf PORTB ; Place “0” into port b latch register
0002 0CC1 00156 movlw b’11000001’ ; RB7;:RB6, RB0 set to inputs
0003 0006 00157 tris PORTB ; Move to tris registers
0004 0040 00158 clrw ; Place 0 into W
0005 0065 00159 clrf PORTA ; Place all ZERO into latch
0006 0005 00160 tris PORTA ; Make all pins outputs to be safe..
0007 0586 00161 bsf PORTB,GNDON ; TEST ONLY-RESET PIC-NOT NEEDED IN REAL DESIGN!
0008 00162 clearram
0008 0C10 00163 movlw 010h ; Place start of buffer into W
0009 0027 00164 movwf COUNT ; Use count for RAM pointer
000A 00165 loopclrram
00166 addrtofsr COUNT ; Set up FSR
000A 0C10 M movlw STARTCALBYTE ; Place base address into W
000B 0087 M subwf COUNT,w ; Offset by STARTCALBYTE
000C 0024 M movwf FSR ; Place into FSR
000D 06A4 M btfsc FSR,5 ; Shift bits 4,5 to 5,6
000E 05C4 M bsf FSR,6
000F 04A4 M bcf FSR,5
0010 0684 M btfsc FSR,4
0011 05A4 M bsf FSR,5
0012 0584 M bsf FSR,4
0013 0060 00167 clrf INDF ; Clear buffer value
0014 02A7 00168 incf COUNT,F ; Move to next reg
0015 0C50 00169 movlw 050h ; Move end of buffer addr to W
0016 0087 00170 subwf COUNT,W ; Check if at last MEM
0017 0743 00171 btfss STATUS,Z ; Skip when at end of counter
0018 0A0A 00172 goto loopclrram ; go back to next location
0019 0486 00173 bcf PORTB,GNDON ; TEST ONLY-LET IT GO-NOT NEEDED IN REAL DESIGN!
001A 00174 calget
001A 006A 00175 clrf CSUMTOTAL ; Clear checksum total byte
2000 Microchip Technology Inc. DS00656B-page 4-9
AN656
001B 0069 00176 clrf DATAREG ; Clear out data receive register
001C 0C10 00177 movlw STARTCALBYTE ; Place RAM start address of first cal byte
001D 002E 00178 movwf ADDRPTR ; Place this into ADDRPTR
001E 00179 waitclockpulse
001E 07C6 00180 btfss PORTB,ISPCLOCK ; Wait for CLOCK high pulse - skip when high
001F 0A1E 00181 goto waitclockpulse ; CLOCK is low - go back and wait!
0020 00182 loopcal
0020 0C08 00183 movlw .8 ; Place 8 into W (8 bits/byte)
0021 0027 00184 movwf COUNT ; set up counter register to count bits
0022 00185 loopsendcal
0022 006B 00186 clrf TIMEHIGH ; Clear timeout counter for high pulse
0023 006C 00187 clrf TIMELOW ; Clear timeout counter for low pulse
0024 00188 waitclkhi
0024 06C6 00189 btfsc PORTB,ISPCLOCK ; Wait for CLOCK high - skip if it is low
0025 0A29 00190 goto waitclklo ; Jump to wait for CLOCK low state
0026 02EB 00191 decfsz TIMEHIGH,F ; Decrement counter - skip if timeout
0027 0A24 00192 goto waitclkhi ; Jump back and wait for CLOCK high again
0028 0A47 00193 goto timeout ; Timed out waiting for high - check data!
0029 00194 waitclklo
0029 07C6 00195 btfss PORTB,ISPCLOCK ; Wait for CLOCK low - skip if it is high
002A 0A2E 00196 goto clockok ; Got a high to low pulse - jump to clockok
002B 02EC 00197 decfsz TIMELOW,F ; Decrement counter - skip if timeout
002C 0A29 00198 goto waitclklo ; Jump back and wait for CLOCK low again
002D 0A47 00199 goto timeout ; Timed out waiting for low - check data!
002E 00200 clockok
002E 0C08 00201 movlw .8 ; Place initial count value into W
002F 0087 00202 subwf COUNT,W ; Subtract from count, place into W
0030 0743 00203 btfss STATUS,Z ; Skip if we are at count 8 (first value)
0031 0A34 00204 goto skipcsumadd ; Skip checksum add if any other count value
0032 0209 00205 movf DATAREG,W ; Place last byte received into W
0033 01EA 00206 addwf CSUMTOTAL,F ; Add to checksum
0034 00207 skipcsumadd
0034 0503 00208 bsf STATUS,C ; Assume data bit is high
0035 07E6 00209 btfss PORTB,ISPDATA ; Skip if the data bit was high
0036 0403 00210 bcf STATUS,C ; Set data bit to low
0037 0369 00211 rlf DATAREG,F ; Rotate next bit into DATAREG
0038 02E7 00212 decfsz COUNT,F ; Skip after 8 bits
0039 0A22 00213 goto loopsendcal ; Jump back and send next bit
00214 addrtofsr ADDRPTR ; Convert pointer address to FSR
003A 0C10 M movlw STARTCALBYTE ; Place base address into W
003B 008E M subwf ADDRPTR,w ; Offset by STARTCALBYTE
003C 0024 M movwf FSR ; Place into FSR
003D 06A4 M btfsc FSR,5 ; Shift bits 4,5 to 5,6
003E 05C4 M bsf FSR,6
003F 04A4 M bcf FSR,5
0040 0684 M btfsc FSR,4
0041 05A4 M bsf FSR,5
0042 0584 M bsf FSR,4
0043 0209 00215 movf DATAREG,W ; Place received byte into W
0044 0020 00216 movwf INDF ; Move recv’d byte into CAL buffer location
0045 02AE 00217 incf ADDRPTR,F ; Move to the next cal byte
0046 0A20 00218 goto loopcal ; Go back for next byte
0047 00219 timeout
0047 0C14 00220 movlw STARTCALBYTE+4 ; check if we received (4) params
0048 008E 00221 subwf ADDRPTR,W ; Move current address pointer to W
0049 0703 00222 btfss STATUS,C ; Skip if we have at least (4)
004A 0A93 00223 goto sendnoise ; not enough params - print and RESET!
004B 0200 00224 movf INDF,W ; Move received checksum into W
004C 00AA 00225 subwf CSUMTOTAL,F ; Subtract received Checksum from calc’d checksum
004D 0743 00226 btfss STATUS,Z ; Skip if CSUM OK
004E 0A9F 00227 goto sendcsumbad ; Checksum bad - print and RESET!
004F 00228 csumok
004F 0426 00229 bcf PORTB,WORKLED ; Turn on WORK LED
0050 0C10 00230 movlw STARTCALBYTE ; Place start pointer into W
0051 008E 00231 subwf ADDRPTR,W ; Subtract from current address
0052 002F 00232 movwf BYTECOUNT ; Place into number of bytes into BYTECOUNT
AN656
DS00656B-page 4-10 2000 Microchip Technology Inc.
0053 002B 00233 movwf TIMEHIGH ; TEMP store into timehigh reg
0054 0C10 00234 movlw STARTCALBYTE ; Place start address into W
0055 002E 00235 movwf ADDRPTR ; Set up address pointer
0056 00236 loopprintnums
00237 addrtofsr ADDRPTR ; Set up FSR
0056 0C10 M movlw STARTCALBYTE ; Place base address into W
0057 008E M subwf ADDRPTR,w ; Offset by STARTCALBYTE
0058 0024 M movwf FSR ; Place into FSR
0059 06A4 M btfsc FSR,5 ; Shift bits 4,5 to 5,6
005A 05C4 M bsf FSR,6
005B 04A4 M bcf FSR,5
005C 0684 M btfsc FSR,4
005D 05A4 M bsf FSR,5
005E 0584 M bsf FSR,4
005F 0380 00238 swapf INDF,W ; Place received char into W
0060 0E0F 00239 andlw 0Fh ; Strip off upper digits
0061 002D 00240 movwf TEMP ; Place into TEMP
0062 0C0A 00241 movlw .10 ; Place .10 into W
0063 00AD 00242 subwf TEMP,F ; Subtract 10 from TEMP
0064 0603 00243 btfsc STATUS,C ; Skip if TEMP is less than 9
0065 0A6D 00244 goto printhiletter ; Greater than 9 - print letter instead
0066 00245 printhinumber
0066 0380 00246 swapf INDF,W ; Place received char into W
0067 0E0F 00247 andlw 0Fh ; Strip off upper digits
0068 002D 00248 movwf TEMP ; Place into TEMP
0069 0C30 00249 movlw ‘0’ ; Place ASCII ‘0’ into W
006A 01CD 00250 addwf TEMP,w ; Add to TEMP, place into W
006B 09AE 00251 call putchar ; Send out char
006C 0A73 00252 goto printlo ; Jump to print next char
006D 00253 printhiletter
006D 0380 00254 swapf INDF,W ; Place received char into W
006E 0E0F 00255 andlw 0Fh ; Strip off upper digits
006F 002D 00256 movwf TEMP ; Place into TEMP
0070 0C37 00257 movlw ‘A’-.10 ; Place ASCII ‘A’ into W
0071 01CD 00258 addwf TEMP,w ; Add to TEMP, place into W
0072 09AE 00259 call putchar ; send out char
0073 00260 printlo
0073 0200 00261 movf INDF,W ; Place received char into W
0074 0E0F 00262 andlw 0Fh ; Strip off upper digits
0075 002D 00263 movwf TEMP ; Place into TEMP
0076 0C0A 00264 movlw .10 ; Place .10 into W
0077 00AD 00265 subwf TEMP,F ; Subtract 10 from TEMP
0078 0603 00266 btfsc STATUS,C ; Skip if TEMP is less than 9
0079 0A81 00267 goto printloletter ; Greater than 9 - print letter instead
007A 00268 printlonumber
007A 0200 00269 movf INDF,W ; Place received char into W
007B 0E0F 00270 andlw 0Fh ; Strip off upper digits
007C 002D 00271 movwf TEMP ; Place into TEMP
007D 0C30 00272 movlw ‘0’ ; Place ASCII ‘0’ into W
007E 01CD 00273 addwf TEMP,w ; Add to TEMP, place into W
007F 09AE 00274 call putchar ; send out char
0080 0A87 00275 goto printnext ; jump to print next char
0081 00276 printloletter
0081 0200 00277 movf INDF,W ; Place received char into W
0082 0E0F 00278 andlw 0Fh ; Strip off upper digits
0083 002D 00279 movwf TEMP ; Place into TEMP
0084 0C37 00280 movlw ‘A’-.10 ; Place ASCII ‘A’ into W
0085 01CD 00281 addwf TEMP,w ; Add to TEMP, place into W
0086 09AE 00282 call putchar ; send out char
0087 00283 printnext
0087 0C7C 00284 movlw ‘|’ ; Place ASCII ‘|’ into W
0088 09AE 00285 call putchar ; Send out character
0089 028E 00286 incf ADDRPTR,W ; Go to next buffer value
008A 0E0F 00287 andlw 0Fh ; And with F
008B 0643 00288 btfsc STATUS,Z ; Skip if this is NOT multiple of 16
2000 Microchip Technology Inc. DS00656B-page 4-11
AN656
008C 09A9 00289 call printcrlf ; Print CR and LF every 16 chars
008D 02AE 00290 incf ADDRPTR,F ; go to next address
008E 02EF 00291 decfsz BYTECOUNT,F ; Skip after last byte
008F 0A56 00292 goto loopprintnums ; Go back and print next char
0090 09A9 00293 call printcrlf ; Print CR and LF
0091 05A3 00294 bsf STATUS,PA0 ; Set page bit to page 1
Message[306]: Crossing page boundary -- ensure page bits are set.
0092 0A6B 00295 goto programpartisp ; Go to program part through ISP
0093 00296 sendnoise
0093 0C4E 00297 movlw ‘N’ ; Place ‘N’ into W
0094 09AE 00298 call putchar ; Send char in W to terminal
0095 0C4F 00299 movlw ‘O’ ; Place ‘O’ into W
0096 09AE 00300 call putchar ; Send char in W to terminal
0097 0C49 00301 movlw ‘I’ ; Place ‘I’ into W
0098 09AE 00302 call putchar ; Send char in W to terminal
0099 0C53 00303 movlw ‘S’ ; Place ‘S’ into W
009A 09AE 00304 call putchar ; Send char in W to terminal
009B 0C45 00305 movlw ‘E’ ; Place ‘E’ into W
009C 09AE 00306 call putchar ; Send char in W to terminal
009D 09A9 00307 call printcrlf ; Print CR and LF
009E 0A1A 00308 goto calget ; RESET!
009F 00309 sendcsumbad
009F 0C43 00310 movlw ‘C’ ; Place ‘C’ into W
00A0 09AE 00311 call putchar ; Send char in W to terminal
00A1 0C53 00312 movlw ‘S’ ; Place ‘S’ into W
00A2 09AE 00313 call putchar ; Send char in W to terminal
00A3 0C55 00314 movlw ‘U’ ; Place ‘U’ into W
00A4 09AE 00315 call putchar ; Send char in W to terminal
00A5 0C4D 00316 movlw ‘M’ ; Place ‘M’ into W
00A6 09AE 00317 call putchar ; Send char in W to terminal
00A7 09A9 00318 call printcrlf ; Print CR and LF
00A8 0A1A 00319 goto calget ; RESET!
00320
00321 ; ******************************************
00322 ; * printcrlf *
00323 ; * Sends char .13 (Carrage Return) and *
00324 ; * char .10 (Line Feed) to RS-232 port *
00325 ; * by calling putchar. *
00326 ; * RAM used: W *
00327 ; ******************************************
00A9 00328 printcrlf
00A9 0C0D 00329 movlw .13 ; Value for CR placed into W
00AA 09AE 00330 call putchar ; Send char in W to terminal
00AB 0C0A 00331 movlw .10 ; Value for LF placed into W
00AC 09AE 00332 call putchar ; Send char in W to terminal
00AD 0800 00333 retlw 0 ; Done - return!
00334
00335 ; ******************************************
00336 ; * putchar *
00337 ; * Print out the character stored in W *
00338 ; * by toggling the data to the RS-232 *
00339 ; * output pin in software. *
00340 ; * RAM used: W,DATAREG,TEMP1 *
00341 ; ******************************************
00AE 00342 putchar
00AE 0029 00343 movwf DATAREG ; Place character into DATAREG
00AF 0C09 00344 movlw 09h ; Place total number of bits into W
00B0 0028 00345 movwf TEMP1 ; Init TEMP1 for bit counter
00B1 0403 00346 bcf STATUS,C ; Set carry to send start bit
00B2 0AB4 00347 goto putloop1 ; Send out start bit
00B3 00348 putloop
00B3 0329 00349 rrf DATAREG,F ; Place next bit into carry
00B4 00350 putloop1
00B4 0703 00351 btfss STATUS,C ; Skip if carry was set
00B5 0466 00352 bcf PORTB,SEROUT ; Clear RS-232 serial output bit
00B6 0603 00353 btfsc STATUS,C ; Skip if carry was clear
AN656
DS00656B-page 4-12 2000 Microchip Technology Inc.
00B7 0566 00354 bsf PORTB,SEROUT ; Set RS-232 serial output bit
00355 delaybit ; Delay for one bit time
0000 M local dlylabels
M ; 9600 baud, 8 bit, no parity, 104 us per bit, 52 uS per half bit
M ; (8) shift/usage + (2) setup + (1) nop + (3 * 31) literal = (104) 4Mhz
00B8 0C1F M movlw .31 ; place 31 decimal literal into count
00B9 0027 M movwf COUNT ; Initialize COUNT with loop count
00BA 0000 M nop ; Add one cycle delay
00BB M dlylabels
00BB 02E7 M decfsz COUNT,F ; Decrement count until done
00BC 0ABB M goto dlylabels ; Not done delaying - go back!
00BD 02E8 00356 decfsz TEMP1,F ; Decrement bit counter, skip when done!
00BE 0AB3 00357 goto putloop ; Jump back and send next bit
00BF 0566 00358 bsf PORTB,SEROUT ; Send out stop bit
00359 delaybit ; delay for stop bit
0000 M local dlylabels
M ; 9600 baud, 8 bit, no parity, 104 us per bit, 52 uS per half bit
M ; (8) shift/usage + (2) setup + (1) nop + (3 * 31) literal = (104) 4Mhz
00C0 0C1F M movlw .31 ; place 31 decimal literal into count
00C1 0027 M movwf COUNT ; Initialize COUNT with loop count
00C2 0000 M nop ; Add one cycle delay
00C3 M dlylabels
00C3 02E7 M decfsz COUNT,F ; Decrement count until done
00C4 0AC3 M goto dlylabels ; Not done delaying - go back!
00C5 0800 00360 retlw 0 ; Done - RETURN
00361
00362 ; *******************************************************************
00363 ; * ISP routines from PICSTART-16C *
00364 ; * Converted from PIC17C42 to PIC16C5X code by John Day *
00365 ; * Originially written by Jim Pepping *
00366 ; *******************************************************************
0200 00367 ORG 200 ; ISP routines stored on page 1
00368
00369 ; *******************************************************************
00370 ; * poweroffisp *
00371 ; * Power off application PIC - turn off VPP and reset device after *
00372 ; * programming pass is complete *
00373 ; *******************************************************************
0200 00374 poweroffisp
0200 04A6 00375 bcf PORTB,VPPON ; Turn off VPP 13 volts
0201 0586 00376 bsf PORTB,GNDON ; Apply 0 V to MCLR to reset PIC
0202 0CC1 00377 movlw b’11000001’ ; RB6,7 set to inputs
0203 0006 00378 tris PORTB ; Move to tris registers
0204 0486 00379 bcf PORTB,GNDON ; Allow MCLR to go back to 5 volts, deassert reset
0205 0526 00380 bsf PORTB,WORKLED ; Turn off WORK LED
0206 0800 00381 retlw 0 ; Done so return!
00382
00383 ; *******************************************************************
00384 ; * testmodeisp *
00385 ; * Apply VPP voltage to place application PIC into test mode. *
00386 ; * this enables ISP programming to proceed *
00387 ; * RAM used: TEMP *
00388 ; *******************************************************************
0207 00389 testmodeisp
0207 0C08 00390 movlw b’00001000’ ; Serial OFF, LEDS OFF, VPP OFF
0208 0026 00391 movwf PORTB ; Place “0” into port b latch register
0209 04A6 00392 bcf PORTB,VPPON ; Turn off VPP just in case!
020A 0586 00393 bsf PORTB,GNDON ; Apply 0 volts to MCLR
020B 0C01 00394 movlw b’00000001’ ; RB6,7 set to outputs
020C 0006 00395 tris PORTB ; Move to tris registers
020D 0206 00396 movf PORTB,W ; Place PORT B state into W
020E 002D 00397 movwf TEMP ; Move state to TEMP
020F 048D 00398 bcf TEMP,4 ; Turn off MCLR GND
0210 05AD 00399 bsf TEMP,5 ; Turn on VPP voltage
0211 020D 00400 movf TEMP,W ; Place TEMP into W
0212 0026 00401 movwf PORTB ; Turn OFF GND and ON VPP
2000 Microchip Technology Inc. DS00656B-page 4-13
AN656
0213 0546 00402 bsf PORTB,DONELED ; Turn ON GREEN LED
0214 0800 00403 retlw 0 ; Done so return!
00404
00405 ; *******************************************************************
00406 ; * p16cispout *
00407 ; * Send 14-bit data word to application PIC for writing this data *
00408 ; * to it’s program memory. The data to be sent is stored in both *
00409 ; * HIBYTE (6 MSBs only) and LOBYTE. *
00410 ; * RAM used: TEMP, W, HIBYTE (inputs), LOBYTE (inputs) *
00411 ; *******************************************************************
0215 00412 P16cispout
0215 0C0E 00413 movlw .14 ; Place 14 into W for bit counter
0216 002D 00414 movwf TEMP ; Use TEMP as bit counter
0217 04C6 00415 bcf PORTB,ISPCLOCK ; Clear CLOCK line
0218 04E6 00416 bcf PORTB,ISPDATA ; Clear DATA line
0219 0C01 00417 movlw DATISPOUT ; Place tris value for data output
021A 0006 00418 tris PORTB ; Set tris latch as data output
021B 04E6 00419 bcf PORTB,ISPDATA ; Send a start bit (0)
021C 05C6 00420 bsf PORTB,ISPCLOCK ; Set CLOCK output
021D 04C6 00421 bcf PORTB,ISPCLOCK ; Clear CLOCK output (clock start bit)
021E 00422 P16cispoutloop
021E 0403 00423 bcf STATUS,C ; Clear carry bit to start clean
021F 04E6 00424 bcf PORTB,ISPDATA ; Clear DATA bit to start (assume 0)
0220 0329 00425 rrf HIBYTE,F ; Rotate HIBYTE output
0221 032A 00426 rrf LOBYTE,F ; Rotate LOBYTE output
0222 0603 00427 btfsc STATUS,C ; Skip if data bit is zero
0223 05E6 00428 bsf PORTB,ISPDATA ; Set DATA line to send a one
0224 05C6 00429 bsf PORTB,ISPCLOCK ; Set CLOCK output
0225 04C6 00430 bcf PORTB,ISPCLOCK ; Clear CLOCK output (clock bit)
0226 02ED 00431 decfsz TEMP,F ; Decrement bit counter, skip when done
0227 0A1E 00432 goto P16cispoutloop ; Jump back and send next bit
0228 04E6 00433 bcf PORTB,ISPDATA ; Send a stop bit (0)
0229 05C6 00434 bsf PORTB,ISPCLOCK ; Set CLOCK output
022A 04C6 00435 bcf PORTB,ISPCLOCK ; Clear CLOCK output (clock stop bit)
022B 0800 00436 retlw 0 ; Done so return!
00437
00438 ; *******************************************************************
00439 ; * p16cispin *
00440 ; * Receive 14-bit data word from application PIC for reading this *
00441 ; * data from it’s program memory. The data received is stored in *
00442 ; * both HIBYTE (6 MSBs only) and LOBYTE. *
00443 ; * RAM used: TEMP, W, HIBYTE (output), LOBYTE (output) *
00444 ; *******************************************************************
022C 00445 P16cispin
022C 0C0E 00446 movlw .14 ; Place 14 data bit count value into W
022D 002D 00447 movwf TEMP ; Init TEMP and use for bit counter
022E 0069 00448 clrf HIBYTE ; Clear recieved HIBYTE register
022F 006A 00449 clrf LOBYTE ; Clear recieved LOBYTE register
0230 0403 00450 bcf STATUS,C ; Clear carry bit to start clean
0231 04C6 00451 bcf PORTB,ISPCLOCK ; Clear CLOCK output
0232 04E6 00452 bcf PORTB,ISPDATA ; Clear DATA output
0233 0C81 00453 movlw DATISPIN ; Place tris value for data input into W
0234 0006 00454 tris PORTB ; Set up tris latch for data input
0235 05C6 00455 bsf PORTB,ISPCLOCK ; Send a single clock to start things going
0236 04C6 00456 bcf PORTB,ISPCLOCK ; Clear CLOCK to start receive
0237 00457 P16cispinloop
0237 05C6 00458 bsf PORTB,ISPCLOCK ; Set CLOCK bit
0238 0000 00459 nop ; Wait one cycle
0239 0403 00460 bcf STATUS,C ; Clear carry bit, assume 0 read
023A 06E6 00461 btfsc PORTB,ISPDATA ; Check the data, skip if it was zero
023B 0503 00462 bsf STATUS,C ; Set carry bit if data was one
023C 0329 00463 rrf HIBYTE,F ; Move recevied bit into HIBYTE
023D 032A 00464 rrf LOBYTE,F ; Update LOBYTE
023E 04C6 00465 bcf PORTB,ISPCLOCK ; Clear CLOCK line
023F 0000 00466 nop ; Wait one cycle
0240 0000 00467 nop ; Wait one cycle
AN656
DS00656B-page 4-14 2000 Microchip Technology Inc.
0241 02ED 00468 decfsz TEMP,F ; Decrement bit counter, skip when zero
0242 0A37 00469 goto P16cispinloop ; Jump back and receive next bit
0243 05C6 00470 bsf PORTB,ISPCLOCK ; Clock a stop bit (0)
0244 0000 00471 nop ; Wait one cycle
0245 04C6 00472 bcf PORTB,ISPCLOCK ; Clear CLOCK to send bit
0246 0000 00473 nop ; Wait one cycle
0247 0403 00474 bcf STATUS,C ; Clear carry bit
0248 0329 00475 rrf HIBYTE,F ; Update HIBYTE with the data
0249 032A 00476 rrf LOBYTE,F ; Update LOBYTE
024A 0403 00477 bcf STATUS,C ; Clear carry bit
024B 0329 00478 rrf HIBYTE,F ; Update HIBYTE with the data
024C 032A 00479 rrf LOBYTE,F ; Update LOBYTE with the data
024D 04C6 00480 bcf PORTB,ISPCLOCK ; Clear CLOCK line
024E 04E6 00481 bcf PORTB,ISPDATA ; Clear DATA line
024F 0C01 00482 movlw DATISPOUT ; Place tris value for data output into W
0250 0006 00483 tris PORTB ; Set tris to data output
0251 0800 00484 retlw 0 ; Done so RETURN!
00485
00486 ; *******************************************************************
00487 ; * commandisp *
00488 ; * Send 6-bit ISP command to application PIC. The command is sent *
00489 ; * in the W register and later stored in LOBYTE for shifting. *
00490 ; * RAM used: LOBYTE, W, TEMP *
00491 ; *******************************************************************
0252 00492 commandisp
0252 002A 00493 movwf LOBYTE ; Place command into LOBYTE
0253 0C06 00494 movlw CMDISPCNT ; Place number of command bits into W
0254 002D 00495 movwf TEMP ; Use TEMP as command bit counter
0255 04E6 00496 bcf PORTB,ISPDATA ; Clear DATA line
0256 04C6 00497 bcf PORTB,ISPCLOCK ; Clear CLOCK line
0257 0C01 00498 movlw DATISPOUT ; Place tris value for data output into W
0258 0006 00499 tris PORTB ; Set tris to data output
0259 00500 P16cispcmmdoutloop
0259 0403 00501 bcf STATUS,C ; Clear carry bit to start clean
025A 04E6 00502 bcf PORTB,ISPDATA ; Clear the DATA line to start
025B 032A 00503 rrf LOBYTE,F ; Update carry with next CMD bit to send
025C 0603 00504 btfsc STATUS,C ; Skip if bit is supposed to be 0
025D 05E6 00505 bsf PORTB,ISPDATA ; Command bit was a one - set DATA to one
025E 05C6 00506 bsf PORTB,ISPCLOCK ; Set CLOCK line to clock the data
025F 0000 00507 nop ; Wait one cycle
0260 04C6 00508 bcf PORTB,ISPCLOCK ; Clear CLOCK line to clock data
0261 02ED 00509 decfsz TEMP,F ; Decement bit counter TEMP, skip when done
0262 0A59 00510 goto P16cispcmmdoutloop ; Jump back and send next cmd bit
0263 0000 00511 nop ; Wait one cycle
0264 04E6 00512 bcf PORTB,ISPDATA ; Clear DATA line
0265 04C6 00513 bcf PORTB,ISPCLOCK ; Clear CLOCK line
0266 0C81 00514 movlw DATISPIN ; Place tris value for data input into W
0267 0006 00515 tris PORTB ; set as input to avoid any contention
0268 0000 00516 nop ; Wait one cycle
0269 0000 00517 nop ; Wait one cycle
026A 0800 00518 retlw 0 ; Done - return!
00519
00520 ; ********************************************************************
00521 ; * programpartisp *
00522 ; * Main ISP programming loop. Reads data starting at STARTCALBYTE *
00523 ; * and calls programming subroutines to program and verify this *
00524 ; * data into the application PIC. *
00525 ; * RAM used: LOADDR, HIADDR, LODATA, HIDATA, FSR, LOBYTE, HIBYTE*
00526 ; ********************************************************************
026B 00527 programpartisp
026B 0907 00528 call testmodeisp ; Place PIC into test/program mode
026C 0064 00529 clrf FSR ; Point to bank 0
026D 0210 00530 movf STARTCALBYTE,W ; Upper order address of data to be stored into W
026E 0027 00531 movwf HIADDR ; place into counter
026F 0211 00532 movf STARTCALBYTE+1,W ; Lower order address byte of data to be stored
0270 0028 00533 movwf LOADDR ; place into counter
2000 Microchip Technology Inc. DS00656B-page 4-15
AN656
0271 00E8 00534 decf LOADDR,F ; Subtract one from loop constant
0272 02A7 00535 incf HIADDR,F ; Add one for loop constant
0273 00536 programsetptr
0273 0C06 00537 movlw CMDISPINCRADDR ; Increment address command load into W
0274 0952 00538 call commandisp ; Send command to PIC
0275 02E8 00539 decfsz LOADDR,F ; Decrement lower address
0276 0A73 00540 goto programsetptr ; Go back again
0277 02E7 00541 decfsz HIADDR,F ; Decrement high address
0278 0A73 00542 goto programsetptr ; Go back again
0279 0C03 00543 movlw .3 ; Place start pointer into W, offset address
027A 008B 00544 subwf TIMEHIGH,W ; Restore byte count into W
027B 002F 00545 movwf BYTECOUNT ; Place into byte counter
027C 0C12 00546 movlw STARTCALBYTE+2 ; Place start of REAL DATA address into W
027D 002E 00547 movwf ADDRPTR ; Update pointer
027E 00548 programisploop
027E 0C34 00549 movlw UPPER6BITS ; retlw instruction opcode placed into W
027F 0027 00550 movwf HIDATA ; Set up upper bits of program word
00551 addrtofsr ADDRPTR ; Set up FSR to point to next value
0280 0C10 M movlw STARTCALBYTE ; Place base address into W
0281 008E M subwf ADDRPTR,w ; Offset by STARTCALBYTE
0282 0024 M movwf FSR ; Place into FSR
0283 06A4 M btfsc FSR,5 ; Shift bits 4,5 to 5,6
0284 05C4 M bsf FSR,6
0285 04A4 M bcf FSR,5
0286 0684 M btfsc FSR,4
0287 05A4 M bsf FSR,5
0288 0584 M bsf FSR,4
0289 0200 00552 movf INDF,W ; Place next cal param into W
028A 0028 00553 movwf LODATA ; Move it out to LODATA
028B 0208 00554 movf LODATA,W ; Place LODATA into LOBYTE
028C 002A 00555 movwf LOBYTE ;
028D 0207 00556 movf HIDATA,W ; Place HIDATA into HIBYTE
028E 0029 00557 movwf HIBYTE ;
028F 006B 00558 clrf PULSECNT ; Clear pulse counter
0290 00559 pgmispcntloop
0290 05E3 00560 bsf STATUS,VFYYES ; Set verify flag
0291 09B1 00561 call pgmvfyisp ; Program and verify this byte
0292 02AB 00562 incf PULSECNT,F ; Increment pulse counter
0293 0C19 00563 movlw .25 ; Place 25 count into W
0294 008B 00564 subwf PULSECNT,w ; Subtract pulse count from 25
0295 0643 00565 btfsc STATUS,Z ; Skip if NOT 25 pulse counts
0296 0AA9 00566 goto pgmispfail ; Jump to program failed - only try 25 times
0297 0209 00567 movf HIBYTE,w ; Subtract programmed and read data
0298 0087 00568 subwf HIDATA,w
0299 0743 00569 btfss STATUS,Z ; Skip if programmed is OK
029A 0A90 00570 goto pgmispcntloop ; Miscompare - program it again!
029B 020A 00571 movf LOBYTE,w ; Subtract programmed and read data
029C 0088 00572 subwf LODATA,w
029D 0743 00573 btfss STATUS,Z ; Skip if programmed is OK
029E 0A90 00574 goto pgmispcntloop ; Miscompare - program it again!
029F 0040 00575 clrw ; Clear W reg
02A0 01CB 00576 addwf PULSECNT,W ; now do 3 times overprogramming pulses
02A1 01CB 00577 addwf PULSECNT,W
02A2 01CB 00578 addwf PULSECNT,W
02A3 002B 00579 movwf PULSECNT ; Add 3X pulsecount to pulsecount
02A4 00580 pgmisp3X
02A4 04E3 00581 bcf STATUS,VFYYES ; Clear verify flag
02A5 09B1 00582 call pgmvfyisp ; Program this byte
02A6 02EB 00583 decfsz PULSECNT,F ; Decrement pulse counter, skip when done
02A7 0AA4 00584 goto pgmisp3X ; Loop back and program again!
02A8 0AAA 00585 goto prgnextbyte ; Done - jump to program next byte!
02A9 00586 pgmispfail
02A9 0446 00587 bcf PORTB,DONELED ; Failure - clear green LED!
02AA 00588 prgnextbyte
02AA 0C06 00589 movlw CMDISPINCRADDR ; Increiment address command load into W
02AB 0952 00590 call commandisp ; Send command to PIC
AN656
DS00656B-page 4-16 2000 Microchip Technology Inc.
02AC 02AE 00591 incf ADDRPTR,F ; Increment pointer to next address
02AD 02EF 00592 decfsz BYTECOUNT,F ; See if we sent last byte
02AE 0A7E 00593 goto programisploop ; Jump back and send next byte
02AF 0900 00594 call poweroffisp ; Done - power off PIC and reset it!
02B0 00595 self
02B0 0AB0 00596 goto self ; Done with programming - wait here!
00597
00598
00599
00600 ; *******************************************************************
00601 ; * pgmvfyisp *
00602 ; * Program and/or Veryify a word in program memory on the *
00603 ; * application PIC. The data to be programmed is in HIDATA and *
00604 ; * LODATA. *
00605 ; * RAM used: HIBYTE, LOBYTE, HIDATA, LODATA, TEMP *
00606 ; *******************************************************************
02B1 00607 pgmvfyisp
02B1 00608 loadcisp
02B1 0C02 00609 movlw CMDISPLOAD ; Place load data command into W
02B2 0952 00610 call commandisp ; Send load data command to PIC
02B3 0000 00611 nop ; Wait one cycle
02B4 0000 00612 nop ; Wait one cycle
02B5 0000 00613 nop ; Wait one cycle
02B6 0208 00614 movf LODATA,w ; Place LODATA byte into W
02B7 002A 00615 movwf LOBYTE ; Move it to LOBYTE reg
02B8 0207 00616 movf HIDATA,w ; Place HIDATA byte into W
02B9 0029 00617 movwf HIBYTE ; Move it to HIBYTE reg
02BA 0915 00618 call P16cispout ; Send data to PIC
02BB 0C08 00619 movlw CMDISPPGMSTART ; Place start programming command into W
02BC 0952 00620 call commandisp ; Send start programming command to PIC
02BD 00621 delay100us
02BD 0C20 00622 movlw .32 ; Place 32 into W
02BE 0000 00623 nop ; Wait one cycle
02BF 002D 00624 movwf TEMP ; Move it to TEMP for delay counter
02C0 00625 loopprgm
02C0 02ED 00626 decfsz TEMP,F ; Decrement TEMP, skip when delay done
02C1 0AC0 00627 goto loopprgm ; Jump back and loop delay
02C2 0C0E 00628 movlw CMDISPPGMEND ; Place stop programming command into W
02C3 0952 00629 call commandisp ; Send end programming command to PIC
02C4 07E3 00630 btfss STATUS,VFYYES ; Skip if we are supposed to verify this time
02C5 0800 00631 retlw 0 ; Done - return!
02C6 0000 00632 nop ; Wait one cycle
02C7 00633 readcisp
02C7 0C04 00634 movlw CMDISPREAD ; Place read data command into W
02C8 0952 00635 call commandisp ; Send read data command to PIC
02C9 092C 00636 call P16cispin ; Read programmed data
02CA 0800 00637 retlw 0 ; Done - return!
00638 END
2000 Microchip Technology Inc. DS00656B-page 4-17
AN656
MEMORY USAGE MAP (‘X’ = Used, ‘-’ = Unused)
0000 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
0040 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
0080 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
00C0 : XXXXXX---------- ---------------- ---------------- ----------------
0200 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
0240 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
0280 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX
02C0 : XXXXXXXXXXX----- ---------------- ---------------- ----------------
07C0 : ---------------- ---------------- ---------------- ---------------X
0FC0 : ---------------- ---------------- ---------------- ---------------X
All other memory blocks unused.
Program Memory Words Used: 402
Program Memory Words Free: 1646
Errors : 0
Warnings : 0 reported, 0 suppressed
Messages : 2 reported, 0 suppressed
AN656
DS00656B-page 4-18 2000 Microchip Technology Inc.
APPENDIX B:
MPASM 01.40.01 Intermediate ISPTEST.ASM 3-31-1997 10:55:57 PAGE 1
LOC OBJECT CODE LINE SOURCE TEXT
VALUE
00001 ; Filename: ISPTEST.ASM
00002 ; **********************************************
00003 ; * Author: John Day *
00004 ; * Sr. Field Applications Engineer *
00005 ; * Microchip Technology *
00006 ; * Revision: 1.0 *
00007 ; * Date August 25, 1995 *
00008 ; * Part: PIC16CXX *
00009 ; * Compiled using MPASM V1.40 *
00010 ; **********************************************
00011 ; * Include files: *
00012 ; * P16CXX.ASM *
00013 ; **********************************************
00014 ; * Fuses: OSC: XT (4.0 Mhz xtal) *
00015 ; * WDT: OFF *
00016 ; * CP: OFF *
00017 ; * PWRTE: OFF *
00018 ; **************************************************************************
00019 ; * This program is intended to be used as a code example to *
00020 ; * show how to comunicate with a manufacturing test jig that *
00021 ; * allows this PIC16CXX device to self program. The RB6 and RB7 *
00022 ; * lines of this PIC16CXX device are used to clock the data from *
00023 ; * this device to the test jig (running ISPPRGM.ASM). Once the *
00024 ; * PIC16C58 running ISPPRGM in the test jig receives the data, *
00025 ; * it places this device in test mode and programs these parameters. *
00026 ; * The code with comments “TEST -“ is used to create some fakecalibration *
00027 ; * parameters that are first written to addresses STARTCALBYTE through *
00028 ; * ENDCALBYTE and later used to call the self-programming algorithm. *
00029 ; * Replace this code with your parameter calculation procedure, *
00030 ; * placing each parameter into the STARTCALBYTE to ENDCALBYTE *
00031 ; * file register addresses (16 are used in this example). The address *
00032 ; * “lookuptable” is used by the main code later on for the final lookup *
00033 ; * table of calibration constants. 16 words are reserved for this lookup *
00034 ; * table. *
00035 ; **************************************************************************
00036 ; * Program Memory: *
00037 ; * 49 Words - communication with test jig *
00038 ; * 17 Words - calibration look-up table (16 bytes of data) *
00039 ; * 13 Words - Test Code to generate Calibration Constants *
00040 ; * RAM Memory: *
00041 ; * 16 Bytes -Temporary- Store 16 bytes of calibration constant*
00042 ; * 4 Bytes -Temporary- Store 4 bytes of temp variables *
00043 ; **************************************************************************
00044
Warning[217]: Hex file format specified on command line.
00045 list p=16C71,f=inhx8m
00046 include <p16C71.inc>
00001 LIST
00002 ; P16C71.INC Standard Header File, Version 1.00 Microchip Technology, Inc.
00142 LIST
2007 3FF1 00047 __CONFIG _CP_OFF&_WDT_OFF&_XT_OSC&_PWRTE_OFF
00048
00049 ; ************************************
00050 ; * Port A (RA0-RA4) bit definitions *
00051 ; ************************************
00052 ; Port A is not used in this test program
00053
00054 ; ************************************
2000 Microchip Technology Inc. DS00656B-page 4-19
AN656
00055 ; * Port B (RB0-RB7) bit definitions *
00056 ; ************************************
00057 #define CLOCK 6 ; clock line for ISP
00058 #define DATA 7 ; data line for ISP
00059 ; Port pins RB0-5 are not used in this test program
00060
00061 ; ************************************
00062 ; * RAM register usage definition *
00063 ; ************************************
0000000C 00064 CSUMTOTAL EQU 0Ch ; Address for checksum var
0000000D 00065 COUNT EQU 0Dh ; Address for COUNT var
0000000E 00066 DATAREG EQU 0Eh ; Address for Data output register var
0000000F 00067 COUNTDLY EQU 0Fh ; Address for clock delay counter
00068
00069 ; These two symbols are used for the start and end address
00070 ; in RAM where the calibration bytes are stored. There are 16 bytes
00071 ; to be stored in this example; however, you can increase or
00072 ; decrease the number of bytes by changing the STARTCALBYTE or ENDCALBYTE
00073 ; address values.
00074
00000010 00075 STARTCALBYTE EQU 10h ; Address pointer for start CAL byte
0000002F 00076 ENDCALBYTE EQU 2Fh ; Address pointer for end CAL byte
00077
00078 ; Table length of lookup table (number of CAL parameters to be stored)
00079
00000020 00080 CALTABLELENGTH EQU ENDCALBYTE - STARTCALBYTE + 1
00081
0000 00082 ORG 0
00083 ; ******************************************************************
00084 ; * testcode routine *
00085 ; * TEST code - sets up RAM register with register address as data *
00086 ; * Uses file register STARTCALBYTE through ENDCALBYTE to store the*
00087 ; * calibration values that are to be programmed into the lookup *
00088 ; * table by the test jig running ISPPRGM. *
00089 ; * Customer would place calibration code here and make sure that *
00090 ; * calibration constants start at address STARTCALBYTE *
00091 ; ******************************************************************
0000 00092 testcode
0000 3010 00093 movlw STARTCALBYTE ; TEST -
0001 0084 00094 movwf FSR ; TEST - Init FSR with start of RAM addres
0002 00095 looptestram
0002 0804 00096 movf FSR,W ; TEST - Place address into W
0003 0080 00097 movwf INDF ; TEST - Place address into RAM data byte
0004 0A84 00098 incf FSR,F ; TEST - Move to next address
0005 0804 00099 movf FSR,W ; TEST - Place current address into W
0006 3C30 00100 sublw ENDCALBYTE+1 ; TEST - Subtract from end of RAM
0007 1D03 00101 btfss STATUS,Z ; TEST - Skip if at END of ram
0008 2802 00102 goto looptestram ; TEST - Jump back and init next RAM byte
0009 0103 00103 clrw ; TEST - Clear W
000A 200F 00104 call lookuptable ; TEST - Get first CAL value from lookup table
000B 3CFF 00105 sublw 0FFh ; TEST - Check if lookup CAL table is blank
000C 1903 00106 btfsc STATUS,Z ; TEST - Skip if table is NOT blank
000D 2830 00107 goto calsend ; TEST - Table blank - send out cal parameters
000E 00108 mainloop
000E 280E 00109 goto mainloop ; TEST - Jump back to self since CAL is done
00110
00111 ; ******************************************************************
00112 ; * lookuptable *
00113 ; * Calibration constants look-up table. This is where the CAL *
00114 ; * Constants will be stored via ISP protocol later. Note it is *
00115 ; * blank, since these values will be pogrammed by the test jig *
00116 ; * running ISPPRGM later. *
00117 ; * Input Variable: W stores index for table lookup *
00118 ; * Output Variable: W returns with the calibration constant *
AN656
DS00656B-page 4-20 2000 Microchip Technology Inc.
00119 ; * NOTE: Blank table when programmed reads “FF” for all locations *
00120 ; ******************************************************************
000F 00121 lookuptable
000F 0782 00122 addwf PCL,F ; Place the calibration constant table here!
00123
002F 00124 ORG lookuptable + CALTABLELENGTH
002F 34FF 00125 retlw 0FFh ; Return FF at last location for a blank table
00126
00127 ; ******************************************************************
00128 ; * calsend subroutine *
00129 ; * Send the calibration data stored in locations STARTCALBYTE *
00130 ; * through ENDCALBYTE in RAM to the programming jig using a serial*
00131 ; * clock and data protocol *
00132 ; * Input Variables: STARTCALBYTE through ENDCALBYTE *
00133 ; ******************************************************************
0030 00134 calsend
0030 018C 00135 clrf CSUMTOTAL ; Clear CSUMTOTAL reg for delay counter
0031 018D 00136 clrf COUNT ; Clear COUNT reg to delay counter
0032 00137 delayloop ; Delay for 100 mS to wait for prog jig wakeup
0032 0B8D 00138 decfsz COUNT,F ; Decrement COUNT and skip when zero
0033 2832 00139 goto delayloop ; Go back and delay again
0034 0B8C 00140 decfsz CSUMTOTAL,F ; Decrement CSUMTOTAL and skip when zero
0035 2832 00141 goto delayloop ; Go back and delay again
0036 0186 00142 clrf PORTB ; Place “0” into port b latch register
0037 1683 00143 bsf STATUS,RP0 ; Switch to bank 1
0038 303F 00144 movlw b’00111111’ ; RB6,7 set to outputs
Message[302]: Register in operand not in bank 0. Ensure that bank bits are correct.
0039 0086 00145 movwf TRISB ; Move to TRIS registers
003A 1283 00146 bcf STATUS,RP0 ; Switch to bank 0
003B 018C 00147 clrf CSUMTOTAL ; Clear checksum total byte
003C 3001 00148 movlw high lookuptable+1 ; place MSB of first addr of cal table into W
003D 204D 00149 call sendcalbyte ; Send the high address out
003E 3010 00150 movlw low lookuptable+1 ; place LSB of first addr of cal table into W
003F 204D 00151 call sendcalbyte ; Send low address out
0040 3010 00152 movlw STARTCALBYTE ; Place RAM start address of first cal byte
0041 0084 00153 movwf FSR ; Place this into FSR
0042 00154 loopcal
0042 0800 00155 movf INDF,W ; Place data into W
0043 204D 00156 call sendcalbyte ; Send the byte out
0044 0A84 00157 incf FSR,F ; Move to the next cal byte
0045 0804 00158 movf FSR,W ; Place byte address into W
0046 3C30 00159 sublw ENDCALBYTE+1 ; Set Z bit if we are at the end of CAL data
0047 1D03 00160 btfss STATUS,Z ; Skip if we are done
0048 2842 00161 goto loopcal ; Go back for next byte
0049 080C 00162 movf CSUMTOTAL,W ; place checksum total into W
004A 204D 00163 call sendcalbyte ; Send the checksum out
004B 0186 00164 clrf PORTB ; clear out port pins
004C 00165 calsenddone
004C 284C 00166 goto calsenddone ; We are done - go home!
00167
00168 ; ******************************************************************
00169 ; * sendcalbyte subroutine *
00170 ; * Send one byte of calibration data to the programming jig *
00171 ; * Input Variable: W contains the byte to be sent *
00172 ; ******************************************************************
004D 00173 sendcalbyte
004D 008E 00174 movwf DATAREG ; Place send byte into data register
004E 078C 00175 addwf CSUMTOTAL,F ; Update checksum total
004F 3008 00176 movlw .8 ; Place 8 into W
0050 008D 00177 movwf COUNT ; set up counter register
0051 00178 loopsendcal
0051 1706 00179 bsf PORTB,CLOCK ; Set clock line high
0052 205C 00180 call delaysend ; Wait for test jig to synch up
0053 0D8E 00181 rlf DATAREG,F ; Rotate to next bit
0054 1786 00182 bsf PORTB,DATA ; Assume data bit is high
0055 1C03 00183 btfss STATUS,C ; Skip if the data bit was high
2000 Microchip Technology Inc. DS00656B-page 4-21
AN656
0056 1386 00184 bcf PORTB,DATA ; Set data bit to low
0057 1306 00185 bcf PORTB,CLOCK ; Clear clock bit to clock data out
0058 205C 00186 call delaysend ; Wait for test jig to synch up
0059 0B8D 00187 decfsz COUNT,F ; Skip after 8 bits
005A 2851 00188 goto loopsendcal ; Jump back and send next bit
005B 0008 00189 return ; We are done with this byte so return!
00190
00191 ; ******************************************************************
00192 ; * delaysend subroutine *
00193 ; * Delay for 50 ms to wait for the programming jig to synch up *
00194 ; ******************************************************************
005C 00195 delaysend
005C 3010 00196 movlw 10h ; Delay for 16 loops
005D 008F 00197 movwf COUNTDLY ; Use COUNTDLY as delay count variable
005E 00198 loopdelaysend
005E 0B8F 00199 decfsz COUNTDLY,F ; Decrement COUNTDLY and skip when done
005F 285E 00200 goto loopdelaysend ; Jump back for more delay
0060 0008 00201 return
00202 END
MEMORY USAGE MAP (‘X’ = Used, ‘-’ = Unused)
0000 : XXXXXXXXXXXXXXXX ---------------- ---------------X XXXXXXXXXXXXXXXX
0040 : XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX X--------------- ----------------
2000 : -------X-------- ---------------- ---------------- ----------------
All other memory blocks unused.
Program Memory Words Used: 66
Program Memory Words Free: 958
Errors : 0
Warnings : 1 reported, 0 suppressed
Messages : 1 reported, 0 suppressed
Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates.
It is your responsibility to ensure that your application meets with your specifications. No representation or warranty is given and no liability is assumed by
Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights
arising from such use or otherwise. Use of Microchip’s products as critical components in life support systems is not authorized except with express written
approval by Microchip. No licenses are conveyed, implicitly or otherwise, except as maybe explicitly expressed herein, under any intellectual property
rights. The Microchip logo and name are registered trademarks of Microchip Technology Inc. in the U.S.A. and other countries. All rights reserved. All other
trademarks mentioned herein are the property of their respective companies.
DS30277C-pa
g
e 4-22
2000 Microchip Technology Inc.
All rights reserved. © 2000 Microchip Technology Incorporated. Printed in the USA. 5/00 Printed on recycled paper.
AMERICAS
Corporate Office
Microchip Technology Inc.
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-786-7200 Fax: 480-786-7277
Technical Support: 480-786-7627
Web Address: http://www.microchip.com
Atlanta
Microchip Technology Inc.
500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: 770-640-0034 Fax: 770-640-0307
Boston
Microchip Technology Inc.
5 Mount Royal Avenue
Marlborough, MA 01752
Tel: 508-480-9990 Fax: 508-480-8575
Chicago
Microchip Technology Inc.
333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: 630-285-0071 Fax: 630-285-0075
Dallas
Microchip Technology Inc.
4570 Westgrove Drive, Suite 160
Addison, TX 75248
Tel: 972-818-7423 Fax: 972-818-2924
Dayton
Microchip Technology Inc.
Two Prestige Place, Suite 150
Miamisburg, OH 45342
Tel: 937-291-1654 Fax: 937-291-9175
Detroit
Microchip Technology Inc.
Tri-Atria Office Building
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: 248-538-2250 Fax: 248-538-2260
Los Angeles
Microchip Technology Inc.
18201 Von Karman, Suite 1090
Irvine, CA 92612
Tel: 949-263-1888 Fax: 949-263-1338
New York
Microchip Technology Inc.
150 Motor Parkway, Suite 202
Hauppauge, NY 11788
Tel: 631-273-5305 Fax: 631-273-5335
San Jose
Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: 408-436-7950 Fax: 408-436-7955
AMERICAS (continued)
Toronto
Microchip Technology Inc.
5925 Airport Road, Suite 200
Mississauga, Ontario L4V 1W1, Canada
Tel: 905-405-6279 Fax: 905-405-6253
ASIA/PACIFIC
China - Beijing
Microchip Technology, Beijing
Unit 915, 6 Chaoyangmen Bei Dajie
Dong Erhuan Road, Dongcheng District
New China Hong Kong Manhattan Building
Beijing, 100027, P.R.C.
Tel: 86-10-85282100 Fax: 86-10-85282104
China - Shanghai
Microchip Technology
Unit B701, Far East International Plaza,
No. 317, Xianxia Road
Shanghai, 200051, P.R.C.
Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
Hong Kong
Microchip Asia Pacific
Unit 2101, Tower 2
Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: 852-2-401-1200 Fax: 852-2-401-3431
India
Microchip Technology Inc.
India Liaison Office
No. 6, Legacy, Convent Road
Bangalore, 560 025, India
Tel: 91-80-229-0061 Fax: 91-80-229-0062
Japan
Microchip Technology Intl. Inc.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa, 222-0033, Japan
Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Korea
Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea
Tel: 82-2-554-7200 Fax: 82-2-558-5934
ASIA/PACIFIC (continued)
Singapore
Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore, 188980
Tel: 65-334-8870 Fax: 65-334-8850
Taiwan
Microchip Technology Taiwan
10F-1C 207
Tung Hua North Road
Tai p ei , Ta i wa n
Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
EUROPE
Denmark
Microchip Technology Denmark ApS
Regus Business Centre
Lautrup hoj 1-3
Ballerup DK-2750 Denmark
Tel: 45 4420 9895 Fax: 45 4420 9910
France
Arizona Microchip Technology SARL
Parc d’Activite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Germany
Arizona Microchip Technology GmbH
Gustav-Heinemann-Ring 125
D-81739 München, Germany
Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Italy
Arizona Microchip Technology SRL
Centro Direzionale Colleoni
Palazzo Taurus 1 V. Le Colleoni 1
20041 Agrate Brianza
Milan, Italy
Tel: 39-039-65791-1 Fax: 39-039-6899883
United Kingdom
Arizona Microchip Technology Ltd.
505 Eskdale Road
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: 44 118 921 5858 Fax: 44-118 921-5835
03/23/00
WORLDWIDE SALES AND SERVICE
Microchip received QS-9000 quality system
certification for its worldwide headquarters,
design and wafer fabrication facilities in
Chandler and Tempe, Arizona in July 1999. The
Company’s quality system processes and
procedures are QS-9000 compliant for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping
devices, Serial EEPROMs and microperipheral
products. In addition, Microchip’s quality
system for the design and manufacture of
development systems is ISO 9001 certified.
