KSZ8873RLLI - MICREL SEMICONDUCTOR - Datasheet.Technology

 2017 Microchip Technology Inc. DS00002348A-page 1

Features

• Advanced Switch Features

- IEEE 802.1q VLAN Support for Up to 16 Groups

(Full Range of VLAN IDs)

- VLAN ID Tag/Untag Options, Per Port Basis

- IEEE 802.1p/q Tag Insertion or Removal on a

Per Port Basis (Egress)

- Programmable Rate Limiting at the Ingress and

Egress on a Per Port Basis

- Broadcast Storm Protection with Percent Con-

trol (Global and Per Port Basis)

- IEEE 802.1d Rapid Spanning Tree Protocol

Support

- Tail Tag Mode (1 byte Added before FCS) Sup-

port at Port 3 to Inform the Processor which

Ingress Port Receives the Packet and its Prior-

ity

- Bypass Feature that Automatically Sustains the

Switch Function between Port 1 and Port 2

when CPU (Port 3 Interface) Goes into Sleep

Mode

- Self-Address Filtering

- Individual MAC Address for Port 1 and Port 2

- Supports RMII Interface and 50 MHz Reference

Clock Output

- MAC MII Interface Supports Both MAC and

PHY Modes

- IGMP Snooping (IPv4) Support for Multicast

Packet Filtering

- IPv4/IPv6 QoS Support

- MAC Filtering Function to Forward Unknown

Unicast Packets to Specified Port

• Comprehensive Configuration Register Access

- Serial Management Interface (SMI) to All Inter-

nal Registers

- MII Management (MIIM) Interface to PHY Reg-

isters

- High Speed SPI and I2C Interface to All Internal

Registers

- I/O Pins Strapping and EEPROM to Program

Selective Registers in Unmanaged Switch

Mode

- Control Registers Configurable on the Fly (Port-

Priority, 802.1p/d/q, AN…)

• QoS/CoS Packet Prioritization Support

• Per Port, 802.1p and DiffServ-Based

- Re-Mapping of 802.1p Priority Field Per Port

basis, Four Priority Levels

• Proven Integrated 3-Port 10/100 Ethernet Switch

- 3rd Generation Switch with Three MACs and

Two PHYs Fully Compliant with IEEE 802.3u

Standard

- Non-Blocking Switch Fabric Ensures Fast

Packet Delivery by Utilizing a 1k MAC Address

Lookup Table and a Store-and-Forward Archi-

tecture

- Full-Duplex IEEE 802.3x Flow Control (PAUSE)

with Force Mode Option

- Half-Duplex Back Pressure Flow Control

- HP Auto MDI-X for Reliable Detection of and

Correction for Straight-Through and Crossover

Cables with Disable and Enable Option

-LinkMD

® TDR-Based Cable Diagnostics Permit

Identification of Faulty Copper Cabling on Port 2

- Comprehensive LED Indicator Support for Link,

Activity, Full-/Half-Duplex and 10/100 Speed

- HBM ESD Rating 3 kV

• Switch Monitoring Features

- Port Mirroring/Monitoring/Sniffing: Ingress and/

or Egress Traffic to Any Port or MII

- MIB Counters for Fully Compliant Statistics

Gathering 34 MIB Counters Per Port

- Loopback Modes for Remote Diagnostic of Fail-

ure

• Low Power Dissipation

- Full-Chip Software Power-Down (Register Con-

figuration Not Saved)

- Full-Chip Hardware Power-Down (Register

Configuration Not Saved)

- Energy-Detect Mode Support

- Dynamic Clock Tree Shutdown Feature

- Per Port Based Software Power-Save on PHY

(Idle Link Detection, Register Configuration Pre-

served)

- Voltages: Single 3.3V Supply with Internal 1.8V

LDO for 3.3V VDDIO

- Optional 3.3V, 2.5V, and 1.8V for VDDIO

- Transceiver Power 3.3V for VDDA_3.3

• Industrial Temperature Range: –40°C to +85°C

• Available in a 64-Pin LQFP, Lead-Free Package

Applications

• VoIP Phone

• Set-Top/Game Box

• Automotive Ethernet

• Industrial Control

• IPTV POF

• SOHO Residential Gateway

• Broadband Gateway/Firewall/VPN

• Integrated DSL/Cable Modem

• Wireless LAN Access Point + Gateway

• Standalone 10/100 Switch

KSZ8873MLL/FLL/RLL

Integrated 3-Port 10/100 Managed Switch

with PHYs

KSZ8873MLL/FLL/RLL

DS00002348A-page 2  2017 Microchip Technology Inc.

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Customer Notification System

 2017 Microchip Technology Inc. DS00002348A-page 3

KSZ8873MLL/FLL/RLL

Table of Content s

1.0 Introduction ..................................................................................................................................................................................... 4

2.0 Pin Description and Configuration .................................................................................................................................................. 5

3.0 Functional Description .................................................................................................................................................................. 12

4.0 Register Descriptions .................................................................................................................................................................... 38

5.0 Operational Characteristics ........................................................................................................................................................... 74

6.0 Electrical Characteristics ............................................................................................................................................................... 75

7.0 Timing Specifications .................................................................................................................................................................... 77

8.0 Reset Circuit ................................................................................................................................................................................. 88

9.0 Selection of Isolation Transformers .............................................................................................................................................. 89

10.0 Package Outline .......................................................................................................................................................................... 90

Appendix A: Data Sheet Revision History ........................................................................................................................................... 91

The Microchip Web Site ...................................................................................................................................................................... 92

Customer Change Notification Service ............................................................................................................................................... 92

Customer Support ............................................................................................................................................................................... 92

Product Identification System ............................................................................................................................................................. 93

KSZ8873MLL/FLL/RLL

DS00002348A-page 4  2017 Microchip Technology Inc.

1.0 INTRODUCTION

1.1 General Description

The KSZ8873MLL/FLL/RLL are highly integrated 3-port switch-on-a-chip ICs in the industry’s smallest footprint. They

are designed to enable a new generation of low port count, cost-sensitive, and power efficient 10/100 Mbps switch sys-

tems. Low power consumption, advanced power management, and sophisticated QoS features (e.g., IPv6 priority clas-

sification support) make these devices ideal for IPTV, IP-STB, VoIP, automotive, and industrial applications.

The KSZ8873 family is designed to support the GREEN requirement in today’s switch systems. Advanced power man-

agement schemes include hardware power down, software power down, per port power down, and the energy detect

mode that shuts downs the transceiver when a port is idle.

KSZ8873MLL/FLL/RLL also offer a bypass mode. In this mode, the processor connected to the switch through the MII

interface can be shut down without impacting the normal switch operation.

The configurations provided by the KSZ8873 family enables the flexibility to meet requirements of different applications:

• KSZ8873MLL: Two 10/100BASE-T/TX transceivers and one MII interface.

• KSZ8873RLL: Two 10/100BASE-T/TX transceivers and one RMII interface.

• KSZ8873FLL: Two 100BASE-FX transceivers and one MII interface.

The devices are available in RoHS-compliant 64-pin LQFP packages. Industrial-grade and qualified AEC-Q100 Auto-

motive-grade versions are also available.

FIGURE 1-1: SYSTEM BLOCK DIAGRAM

1K LOOK-UP

ENGINE

QUEUE

MANAGEMENT

BUFFER

MANAGEMENT

FRAME

BUFFERS

MIB

COUNTERS

EEPROM

INTERFACE

YTIROIRP ,GNIGGAT NALV ,LORTNOC WOLF ,OFIF

10/100

MAC 1

10/100

MAC 2

10/100

MAC 3

10/100

T/TX/FX

PHY 1

10/100

T/TX/FX

PHY 2

HP AUTO

MDIX

HP AUTO

MDIX

MII/SNI

SPI

CONTROL

REGISTERS

MIIM

SMI

STRAP IN

CONFIGURATION

LED

DRIVERS

I2C

P1 LED[1:0]

P2 LED[1:0]

 2017 Microchip Technology Inc. DS00002348A-page 5

KSZ8873MLL/FLL/RLL

2.0 PIN DESCRIPTION AND CONFIGURATION

FIGURE 2-1: 64-PIN 10 MM X 10 MM LQFP ASSIGNMENT, (TOP VIEW)

P2LED0

VDDC

P1FFC

P3SPD

VDDIO

GND

VDDCO

P1LED1

P1LED0

P2LED1

RSTN

FXSD1

VDDA_1.8

RXM1

RXP1

AGND

TXM1

TXP1

VDDA_3.3

AGND

ISET

VDDA_1.8

RXM2

RXP2

AGND

TXM2

TXP2

FXSD2

PWRDN

GND

P1DPX

P1SPD

P1ANEN

SDA_MDIO

SCL_MDC

INTRN

SPISN

SPIQ

VDDC

GND

SMRXC3

SCOL3

SCRS3

SMRXD30

63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

SMTXD33/EN_REFCLKO_3

GND

SMRXD31

SMRXD32

SMRXD33/REFCLKO_3

SMRXDV3

SMTXER3/MII_LINK_3

SMTXC3/REFCLKI_3

VDDIO

GND

SMTXD30

SMTXD31

SMTXD32

SMTXEN3

KSZ8873MLL/FLL/RLL

DS00002348A-page 6  2017 Microchip Technology Inc.

TABLE 2-1: SIGNALS

Number Pin

Name

Type

Note

2-1 Description

1 RXM1 I/O Physical receive or transmit signal (– differential)

2 RXP1 I/O Physical receive or transmit signal (+ differential)

3AGNDGND

Analog ground

4TXM1I/O

Physical transmit or receive signal (– differential)

5 TXP1 I/O Physical transmit or receive signal (+ differential)

6 VDDA_3.3 P 3.3V analog VDD

7AGNDGND

Analog ground

8 ISET O Set physical transmit output current.

Pull-down this pin with an 11.8k 1% resistor to ground.

9 VDDA_1.8 P 1.8V analog core power input from VDDCO (pin 56).

10 RXM2 I/O Physical receive or transmit signal (– differential)

11 RXP2 I/O Physical receive or transmit signal (+ differential)

12 AGND GND Analog ground

13 TXM2 I/O Physical transmit or receive signal (– differential)

14 TXP2 I/O Physical transmit or receive signal (+ differential)

15 FXSD2 I MLL/RLL: connect to analog ground by pull-down resistor.

FLL: Fiber signal detect/factory test pin

16 PWRDN Ipu Chip power down input (active-low)

17 X1 I 25 MHz or 50 MHz crystal/oscillator clock connections.

Pins (X1, X2) connect to a crystal. If an oscillator is used, X1 connects to a

3.3V tolerant oscillator and X2 is a NC.

Note: Clock is ±50 ppm for both crystal and oscillator, the clock should be

applied to X1 pin before reset voltage goes high.

18 X2 O

19 SMTXEN3 Ipu Switch MII transmit enable

20 SMTXD33/

EN_REFCLKO_3 Ipu/I

MLL/FLL: Switch MII transmit data bit 3

RLL: Strap option : RMII mode Clock selection

PU = Enable REFCLKO_3 output

PD = Disable REFCLKO_3 output

21 SMTXD32/

NC Ipu MLL/FLL: Switch MII transmit data bit 2

RLL: No connection

22 SMTXD31 Ipu Switch MII/RMII transmit data bit 1

23 SMTXD30 Ipu Switch MII/RMII transmit data bit 0

24 GND GND Digital ground

25 VDDIO P 3.3V, 2.5V, or 1.8V digital VDD input power supply for IO with well decoupling

capacitors.

 2017 Microchip Technology Inc. DS00002348A-page 7

KSZ8873MLL/FLL/RLL

26 SMTXC3/

REFCLKI_3 I/O

MLL/FLL: Switch MII transmit clock (MII mode only)

Output in PHY MII mode and SNI mode

Input in MAC MII and RMII mode.

RLL: Reference clock input

Note: Pull-down by resistor is needed if internal reference clock is used in

RLL by register 198 bit 3.

27 SMTXER3/

MII_LINK_3 Ipd

Switch MII transmit error in MII mode

0= MII link indicator from host in MII PHY mode.

1= No link on port 3 MII PHY mode and enable bypass mode.

28 SMRXDV3 Ipu/O

Switch MII receive data valid

Strap option : MII mode selection

PU = PHY mode.

PD = MAC mode (In MAC mode, port 3 MII has to connect a powered active

external PHY for the normal operation)

29 SMRXD33/

REFCLKO_3 Ipu/O

MLL/FLL: Switch MII receive data bit 3/

RLL: Output reference clock in RMII mode.

Strap option : enable auto-negotiation on port 2 (P2ANEN)

PU = enable P2ANEN

PD = disable P2ANEN

30 SMRXD32 Ipu/O

Switch MII receive data bit 2

Strap option : Force the speed on port 2

PU = force port 2 to 100BT if P2ANEN = 0

PD = force port 2 to 10BT if P2ANEN = 0

31 SMRXD31 Ipu/O

Switch MII/RMII receive data bit 1

Strap option : Force duplex mode (P2DPX)

PU = port 2 default to full-duplex mode if P2ANEN = 1 and auto-negotiation

fails. Force port 2 in full-duplex mode if P2ANEN = 0.

PD = Port 2 set to half-duplex mode if P2ANEN = 1 and auto-negotiation fails.

Force port 2 in half-duplex mode if P2ANEN = 0.

32 GND GND Digital ground

33 SMRXD30 Ipu/O

Switch MII/RMII receive data bit 0

Strap option : Force flow control on port 2 (P2FFC)

PU = always enable (force) port 2 flow control feature, regardless of auto-

negotiation result.

PD = port 2 flow control feature is enabled by auto-negotiation result.

34 SCRS3/NC Ipu/O

MLL/FLL: Switch MII carrier sense

RLL: No connection, internal pull-up.

Note: For MLL/FLL part, when chip is configured as MAC mode, this pin

should be driven from CRS pin of PHY or from CRS pin of FPGA with a logic

of (TXEN | RXDV). If only full-duplex is used, then this pin should be pull-

down by 1k resistor.

35 SCOL3/NC Ipu/O MLL/FLL: Switch MII collision detect

RLL: No connection, internal pull-up.

TABLE 2-1: SIGNALS (CONTINUED)

Number Pin

Name

Type

Note

2-1 Description

KSZ8873MLL/FLL/RLL

DS00002348A-page 8  2017 Microchip Technology Inc.

36 SMRXC3/NC I/O

MLL/FLL: Switch MII receive clock.

Output in PHY MII mode

Input in MAC MII mode

RLL: No Connection.

37 GND GND Digital ground

38 VDDC P 1.8V digital core power input from VDDCO (pin 56).

39 SPIQ Ipu/O

SPI slave mode: serial data output

Note: an external pull-up is needed on this pin when it is in use.

Strap option : XCLK Frequency Selection

PU = 25 MHz

PD = 50 MHz

40 SPISN Ipu

SPI slave mode: chip select (active-low)

When SPISN is high, the KSZ8873MLL/FLL/RLL is deselected and SPIQ is

held in high impedance state.

A high-to-low transition is used to initiate SPI data transfer.

Note: an external pull-up is needed on this pin when it is in use.

41 INTRN Opu

Interrupt

Active-low signal to host CPU to indicate an interrupt status bit is set when

lost link. Refer to register 187 and 188.

42 SCL_MDC I/O

SPI slave mode/I2C slave mode: clock input

I2C master mode: clock output

MIIM clock input

43 SDA_MDIO Ipu/O

SPI slave mode: serial data input

I2C master/slave mode: serial data input/output

MIIM: data input/output

Note: an external pull-up is needed on this pin when it is in use.

44 NC NC Unused pin, only this NC pin can be pulled down by a pull-down resistor for

better EMI.

45 P1ANEN Ipu/O PU = enable auto-negotiation on port 1

PD = disable auto-negotiation on port 1

46 P1SPD Ipu/O PU = force port 1 to 100BT if P1ANEN = 0

PD = force port 1 to 10BT if P1ANEN = 0

47 P1DPX Ipu/O

PU = port 1 default to full-duplex mode if P1ANEN = 1 and auto-negotiation

fails. Force port 1 in full-duplex mode if P1ANEN = 0.

PD = port 1 default to half-duplex mode if P1ANEN = 1 and auto-negotiation

fails. Force port 1 in half-duplex mode if P1ANEN = 0.

48 GND GND Digital ground

49 VDDC P 1.8V digital core power input from VDDCO (Pin 56).

50 P1FFC Ipu/O

PU = always enable (force) port 1 flow control feature

PD = port 1 flow control feature enable is determined by auto-negotiation

result.

TABLE 2-1: SIGNALS (CONTINUED)

Number Pin

Name

Type

Note

2-1 Description

 2017 Microchip Technology Inc. DS00002348A-page 9

KSZ8873MLL/FLL/RLL

51 P3SPD Ipd/O PU = force port 3 to 10BT

PD = force port 3 to 100BT (default)

52 NC NC Unused pin. No external connection.

53 NC NC Unused pin. No external connection.

54 VDDIO P 3.3V, 2.5V or 1.8V digital VDD input power supply for IO with well decoupling

capacitors.

55 GND GND Digital ground

56 VDDCO P

1.8V core power voltage output (internal 1.8V LDO regulator output), this

1.8V output pin provides power to both VDDA_1.8 and VDDC input pins.

Note: Internally 1.8V LDO regulator input comes from VDDIO. Do not connect

an external power supply to VDDCO pin. The ferrite bead is requested

between analog and digital 1.8V core power.

57 NC NC Unused pin. No external connection.

58 P1LED1 Ipu/O

Port 1 LED Indicators:

Default: Speed (refer to register 195 bit[5:4])

Strap option : Port 3 flow control selection (P3FFC)

PU = always enable (force) port 3 flow control feature (default)

PD = disable

59 P1LED0 Ipd/O

Port 1 LED Indicators:

Default: Link/Act. (refer to Register 195 bit[5:4])

Strap option : Port 3 duplex mode selection (P3DPX)

PU = port 3 to half-duplex mode

PD = port 3 to full-duplex mode (default)

Note: P1LED0 has weaker internal pull-down, recommend an external pull-

down by a 0.5 k resistor.

TABLE 2-1: SIGNALS (CONTINUED)

Number Pin

Name

Type

Note

2-1 Description

KSZ8873MLL/FLL/RLL

DS00002348A-page 10  2017 Microchip Technology Inc.

60 P2LED1 Ipu/O

Port 2 LED Indicators:

Default: Speed (refer to register 195 bit[5:4])

Strap option : Serial bus configuration

Port 2 LED Indicators:

Default: Link/Act. (refer to register 195 bit[5:4])

Strap option : Serial bus configuration

Serial bus configuration pins to select mode of access to KSZ8873MLL/FLL/

RLL internal registers.

[P2LED1, P2LED0] = [0, 0] — I2C master (EEPROM) mode

(If EEPROM is not detected, the KSZ8873MLL/FLL/RLL will be configured

with the default values of its internal registers and the values of its strap-in

pins.)

Interface Signals Type Description

SPIQ O Not used (tri-stated)

SCL_MDC O I2C clock

SDA_MDIO I/O I2C data I/O

SPISN I Not used

[P2LED1, P2LED0] = [0, 1] — I2C slave mode

The external I2C master will drive the SCL_MDC clock.

The KSZ8873MLL/FLL/RLL device addresses are:

1011_1111 <read>

1011_1110 <write>

Interface Signals Type Description

61 P2LED0 Ipu/O

SPIQ O Not used (tri-stated)

SCL_MDC I I2C clock

SDA_MDIO I/O I2C data I/O

SPISN I Not used

[P2LED1, P2LED0] = [1, 0] — SPI slave mode

Interface Signals Type Description

SPIQ O SPI data out

SCL_MDC I SPI clock

SDA_MDIO I SPI data in

SPISN I SPI chip select

[P2LED1, P2LED0] = [1, 1] – SMI/MIIM mode

In SMI mode, the KSZ8873MLL/FLL/RLL provides access to all its internal 8-

bit registers through its SCL_MDC and SDA_MDIO pins.

In MIIM mode, the KSZ8873MLL/FLL/RLL provides access to its 16-bit MIIM

registers through its SDC_MDC and SDA_MDIO pins.

TABLE 2-1: SIGNALS (CONTINUED)

Number Pin

Name

Type

Note

2-1 Description

 2017 Microchip Technology Inc. DS00002348A-page 11

KSZ8873MLL/FLL/RLL

Note 2-1 P = power supply

GND = ground

I = input

O = output

I/O = bi-directional

Ipu/O = Input with internal pull-up during reset; output pin otherwise.

Ipu = Input with internal pull-up.

Ipd = Input with internal pull-down.

Opu = Output with internal pull-up.

Opd = Output with internal pull-down.

Speed: Low (100BASE-TX), High (10BASE-T)

Full-Duplex: Low (full-duplex), High (half-duplex)

Activity: Toggle (transmit/receive activity)

Link: Low (link), High (no link)

62 RSTN Ipu Hardware reset pin (active-low)

63 FXSD1 I MLL/RLL: Connect to analog ground by pull-down resistor

FLL: Fiber signal detect

64 VDDA_1.8 P 1.8V analog VDD input power supply from VDDCO (Pin 56) through external

ferrite bead and capacitors.

TABLE 2-1: SIGNALS (CONTINUED)

Number Pin

Name

Type

Note

2-1 Description

KSZ8873MLL/FLL/RLL

DS00002348A-page 12  2017 Microchip Technology Inc.

3.0 FUNCTIONAL DESCRIPTION

The KSZ8873MLL/FLL/RLL contains two 10/100 physical layer transceivers and three MAC units with an integrated

Layer 2 managed switch.

The KSZ8873MLL/FLL/RLL has the flexibility to reside in either a managed or unmanaged design. In a managed design,

the host processor has complete control of the KSZ8873MLL/FLL/RLL via the SMI interface, MIIM interface, SPI bus,

or I2C bus. An unmanaged design is achieved through I/O strapping and/or EEPROM programming at system reset

time.

On the media side, the KSZ8873MLL/FLL/RLL supports IEEE 802.3 10BASE-T and 100BASE-TX on both PHY ports.

Physical signal transmission and reception are enhanced through the use of patented analog circuitries that make the

design more efficient and allow for lower power consumption and smaller chip die size.

3.1 Physical Layer Transceiver

3.1.1 100BASE-TX TRANSMIT

The 100BASE-TX transmit function performs parallel-to-serial conversion, 4B/5B coding, scrambling, NRZ-to-NRZI con-

version, and MLT3 encoding and transmission.

The circuitry starts with a parallel-to-serial conversion, which converts the MII data from the MAC into a 125 MHz serial

bit stream. The data and control stream is then converted into 4B/5B coding, followed by a scrambler. The serialized

data is further converted from NRZ-to-NRZI format, and then transmitted in MLT3 current output. The output current is

set by an external 1% 11.8 k resistor for the 1:1 transformer ratio.

The output signal has a typical rise/fall time of 4 ns and complies with the ANSI TP-PMD standard regarding amplitude

balance, overshoot, and timing jitter. The wave-shaped 10BASE-T output is also incorporated into the 100BASE-TX

transmitter.

3.1.2 100BASE-TX RECEIVE

The 100BASE-TX receiver function performs adaptive equalization, DC restoration, MLT3-to-NRZI conversion, data and

clock recovery, NRZI-to-NRZ conversion, de-scrambling, 4B/5B decoding, and serial-to-parallel conversion.

The receiving side starts with the equalization filter to compensate for inter-symbol interference (ISI) over the twisted

pair cable. Because the amplitude loss and phase distortion is a function of the cable length, the equalizer must adjust

its characteristics to optimize performance. In this design, the variable equalizer makes an initial estimation based on

comparisons of incoming signal strength against some known cable characteristics, and then tunes itself for optimiza-

tion. This is an ongoing process and self-adjusts against environmental changes such as temperature variations.

Next, the equalized signal goes through a DC restoration and data conversion block. The DC restoration circuit is used

to compensate for the effect of baseline wander and to improve the dynamic range. The differential data conversion

circuit converts the MLT3 format back to NRZI. The slicing threshold is also adaptive.

The clock recovery circuit extracts the 125 MHz clock from the edges of the NRZI signal. This recovered clock is then

used to convert the NRZI signal into the NRZ format. This signal is sent through the de-scrambler followed by the 4B/

5B decoder. Finally, the NRZ serial data is converted to the MII format and provided as the input data to the MAC.

3.1.3 PLL CLOCK SYNTHESIZER

The KSZ8873MLL/FLL/RLL generates 125 MHz, 62.5 MHz, and 31.25 MHz clocks for system timing. Internal clocks

are generated from an external 25 MHz or 50 MHz crystal or oscillator. KSZ8873RLL can generate a 50 MHz reference

clock for the RMII interface.

3.1.4 SCRAMBLER/DE-SCRAMBLER (100BASE-TX ONLY)

The purpose of the scrambler is to spread the power spectrum of the signal to reduce electromagnetic interference (EMI)

and baseline wander. Transmitted data is scrambled through the use of an 11-bit wide linear feedback shift register

(LFSR). The scrambler generates a 2047-bit non-repetitive sequence, and the receiver then de-scrambles the incoming

data stream using the same sequence as at the transmitter.

3.1.5 100BASE-FX OPERATION

100BASE-FX operation is similar to 100BASE-TX operation with the differences being that the scrambler/de-scrambler

and MLT3 encoder/decoder are bypassed on transmission and reception. In addition, auto-negotiation is bypassed and

auto MDI/MDI-X is disabled.

 2017 Microchip Technology Inc. DS00002348A-page 13

KSZ8873MLL/FLL/RLL

3.1.6 100BASE-FX SIGNAL DETECTION

In 100BASE-FX operation, FXSD (fiber signal detect), input pins 15 and 63, is usually connected to the fiber transceiver

SD (signal detect) output pin. The fiber signal threshold can be selected by register 192 bit 7 and 6 respectively for port

1 and port 2. When FXSD is less than the threshold, no fiber signal is detected and a far-end fault (FEF) is generated.

When FXSD is over the threshold, the fiber signal is detected.

Alternatively, the designer may choose not to implement the FEF feature. In this case, the FXSD input pin is tied high

to force 100BASE-FX mode.

100BASE-FX signal detection is summarized in Table 3-1:

To ensure proper operation, a resistive voltage divider is recommended to adjust the fiber transceiver SD output voltage

swing to match the FXSD pin’s input voltage threshold.

3.1.7 100BASE-FX FAR-END FAULT

A far-end fault (FEF) occurs when the signal detection is logically false on the receive side of the fiber transceiver. The

KSZ8873FLL detects a FEF when its FXSD input is below the Fiber Signal Threshold. When a FEF is detected, the

KSZ8873FLL signals its fiber link partner that a FEF has occurred by sending 84 1’s followed by a zero in the idle period

between frames. By default, FEF is enabled. FEF can be disabled through register setting.

3.1.8 10BASE-T TRANSMIT

The 10BASE-T driver is incorporated with the 100BASE-TX driver to allow for transmission using the same magnetics.

They are internally wave-shaped and pre-emphasized into outputs with a typical 2.3V amplitude. The harmonic contents

are at least 27 dB below the fundamental frequency when driven by an all-ones Manchester-encoded signal.

3.1.9 10BASE-T RECEIVE

On the receive side, input buffers and level detecting squelch circuits are employed. A differential input receiver circuit

and a phase-locked loop (PLL) perform the decoding function. The Manchester-encoded data stream is separated into

clock signal and NRZ data. A squelch circuit rejects signals with levels less than 400 mV or with short pulse widths to

prevent noise at the RXP-or-RXM input from falsely triggering the decoder. When the input exceeds the squelch limit,

the PLL locks onto the incoming signal and the KSZ8873MLL/FLL/RLL decodes a data frame. The receiver clock is

maintained active during idle periods in between data reception.

3.1.10 MDI/MDI-X AUTO CROSSOVER

To eliminate the need for crossover cables between similar devices, the KSZ8873MLL/FLL/RLL supports HP Auto MDI/

MDI-X and IEEE 802.3u standard MDI/MDI-X auto crossover. HP Auto MDI/MDI-X is the default.

The auto-sense function detects remote transmit and receive pairs and correctly assigns transmit and receive pairs for

the KSZ8873MLL/FLL/RLL device. This feature is extremely useful when end users are unaware of cable types and

also saves on an additional uplink configuration connection. The auto-crossover feature can be disabled through the

port control registers or MIIM PHY registers.

The IEEE 802.3u standard MDI and MDI-X definitions are illustrated in Ta bl e 3 - 2 .

TABLE 3-1: FX SIGNAL THRESHOLD

12.0V

01.2V

TABLE 3-2: MDI/MD I-X PIN DEFINITION S

MDI MDI-X

RJ-45 Pins Signals RJ-45 Pins Signal s

1 TD+ 1 RD+

2TD–2RD–

3 RD+ 3 TD+

6 RD– 6 TD–

KSZ8873MLL/FLL/RLL

DS00002348A-page 14  2017 Microchip Technology Inc.

3.1.10.1 Straight Cable

A straight cable connects an MDI device to an MDI-X device, or an MDI-X device to an MDI device. Figure 3-1 depicts

a typical straight cable connection between a NIC card (MDI) and a switch or hub (MDI-X).

FIGURE 3-1: TYPICAL STRAIGHT CABLE CONNECTION

Receive PairTransmit Pair

Receive Pair

Transmit Pair

Modular Connector

(RJ-45)

NIC

Straight

Cable

10/100 Ethernet

Media Dependent Interface

10/100 Ethernet

Media Dependent Interface

Modular Connector

(RJ-45)

HUB

(Repeater or Switch)

 2017 Microchip Technology Inc. DS00002348A-page 15

KSZ8873MLL/FLL/RLL

3.1.10.2 Crossover Cable

A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device.

Figure 3-2 shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).

3.1.11 AUTO-NEGOTIATION

The KSZ8873MLL/FLL/RLL conforms to the auto-negotiation protocol, defined in Clause 28 of the IEEE 802.3u speci-

fication.

Auto-negotiation allows unshielded twisted pair (UTP) link partners to select the best common mode of operation. In

auto-negotiation, link partners advertise their capabilities across the link to each other. If auto-negotiation is not sup-

ported or the KSZ8873MLL/FLL/RLL link partner is forced to bypass auto-negotiation, the KSZ8873MLL/FLL/RLL sets

its operating mode by observing the signal at its receiver. This is known as parallel detection, and allows the

KSZ8873MLL/FLL/RLL to establish link by listening for a fixed signal protocol in the absence of auto-negotiation adver-

tisement protocol.

The link up process is shown in Figure 3-3.

FIGURE 3-2: TYPICAL CROSSOVER CABLE CONNECTION

Receive Pair Receive Pair

Transmit Pair

10/100 Ethernet

Media Dependent Interface

10/100 Ethernet

Media Dependent Interface

Modular Connector (RJ-45)

HUB

(Repeater or Switch)

Modular Connector (RJ-45)

HUB

(Repeater or Switch)

Crossover

Cable

KSZ8873MLL/FLL/RLL

DS00002348A-page 16  2017 Microchip Technology Inc.

FIGURE 3-3: AUTO-NEGOTIATION AND PARALLEL OPERATION

3.1.12 LINKMD® CABLE DIAGNOSTICS

KSZ8873MLL/FLL/RLL supports LinkMD. The LinkMD feature utilizes time domain reflectometry (TDR) to analyze the

cabling plant for common cabling problems such as open circuits, short circuits, and impedance mismatches.

LinkMD works by sending a pulse of known amplitude and duration down the MDI and MDI-X pairs and then analyzes

the shape of the reflected signal. Timing the pulse duration gives an indication of the distance to the cabling fault. Inter-

nal circuitry displays the TDR information in a user-readable digital format.

Cable diagnostics are only valid for copper connections and do not support fiber optic operation.

3.1.12.1 Access

LinkMD is initiated by accessing the PHY special control/status registers {26, 42} and the LinkMD result registers {27,

43} for ports 1 and 2 respectively; and in conjunction with the port registers control 13 for ports 1 and 2 respectively to

disable Auto MDI/MDIX.

Alternatively, the MIIM PHY registers 0 and 29 can be used for LinkMD access.

3.1.12.2 Usage

The following is a sample procedure for using LinkMD with registers {42,43,45} on port 2.

1. Disable auto MDI/MDI-X by writing a ‘1’ to register 45, bit [2] to enable manual control over the differential pair

used to transmit the LinkMD pulse.

START AUTO-NEGOTIATION

FORCE LINK SETTING

LISTEN FOR 10BASE-T

LINK PULSES

LISTEN FOR 100BASE-TX

IDLES

ATTEMPT AUTO-

NEGOTIATION

LINK MODE SET

BYPASS AUTO-NEGOTIATION

AND SET LINK MODE

LINK MODE SET?

PARALLEL

OPERATION

YES

JOIN FLOW

 2017 Microchip Technology Inc. DS00002348A-page 17

KSZ8873MLL/FLL/RLL

2. Start cable diagnostic test by writing a ‘1’ to register 42, bit [4]. This enable bit is self-clearing.

3. Wait (poll) for register 42, bit [4] to return a ‘0’, indicating cable diagnostic test is complete.

4. Read cable diagnostic test results in register 42, bits [6:5]. The results are as follows:

00 = normal condition (valid test)

01 = open condition detected in cable (valid test)

10 = short condition detected in cable (valid test)

11 = cable diagnostic test failed (invalid test)

The ‘11’ case, invalid test, occurs when the KSZ8873MLL/FLL/RLL is unable to shut down the link partner. In this

instance, the test is not run, because it would be impossible for the KSZ8873MLL/FLL/RLL to determine if the detected

signal is a reflection of the signal generated or a signal from another source.

5. Get distance to fault by concatenating register 42, bit [0] and register 43, bits [7:0]; and multiplying the result by

a constant of 0.4. The distance to the cable fault can be determined by the following formula:

EQUATION 3-1:

Concatenated values of registers 42 and 43 are converted to decimal before multiplying by 0.4.

The constant (0.4) may be calibrated for different cabling conditions, including cables with a velocity of propagation that

varies significantly from the norm.

3.2 Power Management

The KSZ8873MLL/FLL/RLL supports enhanced power management features in low power state with energy detection

to ensure low-power dissipation during device idle periods. There are five operation modes under the power manage-

ment function, which is controlled by two bits in Register 195 (0xC3) and one bit in Register 29 (0x1D), 45 (0x2D) as

shown below:

Table 3-3 indicates all internal function blocks status under four different power management operation modes.

3.2.1 NORMAL OPERATION MODE

This is the default setting bit[1:0]=00 in register 195 after the chip power-up or hardware reset. When KSZ8873MLL/

FLL/RLL is in this normal operation mode, all PLL clocks are running, PHY and MAC are on, and the host interface is

ready for CPU read or write.

TABLE 3-3: INTERNAL FUNCTION BLOCK STATUS

KSZ8873MLL/FLL/RLL

Function Blocks

Power Management Operation Modes

Normal Mode Power Saving

Mode Energy Detect

Mode Soft Power Down

Mode

Internal PLL Clock Enabled Enabled Disabled Disabled

Tx/Rx PHY Enabled Rx unused block

disabled Energy detect at Rx Disabled

MAC Enabled Enabled Disabled Disabled

Host Interface Enabled Enabled Disabled Disabled

DDis cetan

· to cable fault in meters0.4 Register 26 bit [0] Register 27 bits [7:0]=

KSZ8873MLL/FLL/RLL

DS00002348A-page 18  2017 Microchip Technology Inc.

During the normal operation mode, the host CPU can set the bit[1:0] in register 195 to transit the current normal oper-

ation mode to any one of the other three power management operation modes.

3.2.2 POWER SAVING MODE

The power saving mode is entered when auto-negotiation mode is enabled, cable is disconnected, and by setting

bit[1:0]=11 in register 195. When KSZ8873MLL/FLL/RLL is in this mode, all PLL clocks are enabled, MAC is on, all inter-

nal registers values will not change, and host interface is ready for CPU read or write. In this mode, it mainly controls

the PHY transceiver on or off based on line status to achieve power saving. The PHY remains transmitting and only

turns off the unused receiver block. Once activity resumes due to plugging a cable or attempting by the far end to estab-

lish link, the KSZ8873MLL/FLL/RLL can automatically enabled the PHY power up to normal power state from power

saving mode.

During this power saving mode, the host CPU can set bit[1:0] =0 in register 195 to transit the current power saving mode

to any one of the other three power management operation modes.

3.2.3 ENERGY DETECT MODE

The energy detect mode provides a mechanism to save more power than in the normal operation mode when the

KSZ8873MLL/FLL/RLL is not connected to an active link partner. In this mode, the device will save up to 50% of the

power. If the cable is not plugged, the KSZ8873MLL/FLL/RLL can automatically enter a low-power state, the energy

detect mode. In this mode, KSZ8873MLL/FLL/RLL will keep transmitting 120 ns width pulses at a rate of 1 pulse/second.

Once activity resumes due to plugging a cable or an attempt by the far end to establish link, the KSZ8873MLL/FLL/RLL

can automatically power up to normal power state in energy detect mode.

Energy detect mode consists of two states, normal power state and low power state. While in low power state, the

KSZ8873MLL/FLL/RLL reduces power consumption by disabling all circuitry except the energy detect circuitry of the

receiver. The energy detect mode is entered by setting bit[1:0]=01 in register 195. When the KSZ8873MLL/FLL/RLL is

in this mode, it will monitor the cable energy. If there is no energy on the cable for a time longer than pre-configured

value at bit[7:0] Go-Sleep time in register 196, KSZ8873MLL/FLL/RLL will go into a low power state. When

KSZ8873MLL/FLL/RLL is in low power state, it will keep monitoring the cable energy. Once the energy is detected from

the cable, KSZ8873MLL/FLL/RLL will enter normal power state. When KSZ8873MLL/FLL/RLL is at normal power state,

it is able to transmit or receive packet from the cable.

It will save about 87% of the power when MII interface is in PHY mode, Pin SMTXER3/MII_LINK_3 is connected to High,

3.2.4 SOFT POWER DOWN MODE

The soft power down mode is entered by setting bit[1:0]=10 in register 195. When KSZ8873MLL/FLL/RLL is in this

mode, all PLL clocks are disabled, the PHY and the MAC are off, all internal registers values will not change. When the

host set bit[1:0]=00 in register 195, this device will be back from current soft power down mode to normal operation

mode.

3.2.5 PORT-BASED POWER DOWN MODE

In addition, the KSZ8873MLL/FLL/RLL features a per-port power down mode. To save power, a PHY port that is not in

use can be powered down via port control register 29 or 45 bit 3, or MIIM PHY register. It saves about 15 mA per port.

3.2.6 HARDWARE POWER DOWN

KSZ8873 supports a hardware power down mode. When the pin PWRDN is activated low, the entire chip is powered

down.

3.3 MAC and Switch

3.3.1 ADDRESS LOOKUP

The internal lookup table stores MAC addresses and their associated information. It contains a 1K unicast address table

plus switching information.

The KSZ8873MLL/FLL/RLL is guaranteed to learn 1K addresses and distinguishes itself from hash-based lookup

tables, which depending on the operating environment and probabilities, may not guarantee the absolute number of

addresses it can learn.

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KSZ8873MLL/FLL/RLL

3.3.2 LEARNING

The internal lookup engine updates its table with a new entry if the following conditions are met:

• The received packet's source address (SA) does not exist in the lookup table.

• The received packet is good; the packet has no receiving errors, and is of legal length.

The lookup engine inserts the qualified SA into the table, along with the port number and time stamp. If the table is full,

the last entry of the table is deleted to make room for the new entry.

3.3.3 MIGRATION

The internal lookup engine also monitors whether a station has moved. If a station has moved, it will update the table

accordingly. Migration happens when the following conditions are met:

• The received packet’s SA is in the table, but the associated source port information is different.

• The received packet is good; the packet has no receiving errors, and is of legal length.

The lookup engine will update the existing record in the table with the new source port information.

3.3.4 AGING

The lookup engine updates the time stamp information of a record whenever the corresponding SA appears. The time

stamp is used in the aging process. If a record is not updated for a period of time, the lookup engine removes the record

from the table. The lookup engine constantly performs the aging process and will continuously remove aging records.

The aging period is about 200 seconds. This feature can be enabled or disabled through register 3 (0x03) bit [2].

3.3.5 FORWARDING

The KSZ8873MLL/FLL/RLL forwards packets using the algorithm that is depicted in the following flowcharts. Figure 3-

4 shows stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and dynamic

table for the destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further modified by span-

ning tree, IGMP snooping, port mirroring, and port VLAN processes to come up with “port to forward 2” (PTF2), as

shown in Figure 3-5. The packet is sent to PTF2.

KSZ8873MLL/FLL/RLL

DS00002348A-page 20  2017 Microchip Technology Inc.

FIGURE 3-4: DESTINATION ADDRESS LOOKUP FLOW CHART, STAGE 1

Start

VLAN ID

Valid?

PTF1= NULL

Search Static

Table

Search complete.

Get PTF1 from

Static MAC Table

Dynamic Table

Search complete.

Get PTF1 from

VLAN Table

Search complete.

Get PTF1 from

Dynamic MAC

Table

PTF1

- Search VLAN table

- Ingress VLAN ltering

- Discard NPVID check

YES

FOUND

NOT

FOUND

NOT

FOUND

This search is based on

DA or DA+FID

This search is based on

DA+FID

 2017 Microchip Technology Inc. DS00002348A-page 21

KSZ8873MLL/FLL/RLL

The KSZ8873MLL/FLL/RLL will not forward the following packets:

1. Error packets: These include framing errors, Frame Check Sequence (FCS) errors, alignment errors, and illegal

size packet errors.

2. IEEE802.3x PAUSE frames: KSZ8873MLL/FLL/RLL intercepts these packets and performs full-duplex flow con-

trol accordingly.

3. "Local" packets: Based on destination address (DA) lookup. If the destination port from the lookup table matches

the port from which the packet originated, the packet is defined as local.

3.3.6 SWITCHING ENGINE

The KSZ8873MLL/FLL/RLL features a high-performance switching engine to move data to and from the MAC’s packet

buffers. It operates in store and forward mode, while the efficient switching mechanism reduces overall latency.

The switching engine has a 32 kb internal frame buffer. This buffer pool is shared between all three ports. There are a

total of 256 buffers available. Each buffer is sized at 128 bytes.

3.3.7 MAC OPERATION

The KSZ8873MLL/FLL/RLL strictly abides by IEEE 802.3 standards to maximize compatibility.

3.3.7.1 Inter Packet Gap (IPG)

If a frame is successfully transmitted, the 96 bits time IPG is measured between the two consecutive MTXEN. If the

current packet is experiencing collision, the 96 bits time IPG is measured from MCRS and the next MTXEN.

3.3.7.2 Back-Off Algorithm

The KSZ8873MLL/FLL/RLL implements the IEEE 802.3 standard for the binary exponential back-off algorithm, and

optional "aggressive mode" back-off. After 16 collisions, the packet is optionally dropped depending on the switch con-

figuration for register 4 (0x04) bit [3].

FIGURE 3-5: DESTINATION ADDRESS RESOLUTION FLOW CHART, STAGE 2

Spanning Tree

Process

PTF1

IGMP Process

Port Mirror

Process

Port VLAN

Membership

Check

PTF2

- Check receiving port's receive enable bit

- Check destination port's transmit enable bit

- Check whether packets are special (BPDU

or specied)

- RX Mirror

- TX Mirror

- RX or TX Mirror

- RX and TX Mirror

- Applied to MAC #1 and MAC #2

- MAC #3 is reserved for

microprocessor

- IGMP will be forwarded to port 3

KSZ8873MLL/FLL/RLL

DS00002348A-page 22  2017 Microchip Technology Inc.

3.3.7.3 Late Collision

If a transmit packet experiences collisions after 512 bit times of the transmission, the packet is dropped.

3.3.7.4 Illegal Frames

The KSZ8873MLL/FLL/RLL discards frames less than 64 bytes and can be programmed to accept frames up to1518

bytes, 1536 bytes, or 1916 bytes. These maximum frame size settings are programmed in register 4 (0x04). Because

the KSZ8873MLL/FLL/RLL supports VLAN tags, the maximum sizing is adjusted when these tags are present.

3.3.7.5 Full-Duplex Flow Control

The KSZ8873MLL/FLL/RLL supports standard IEEE 802.3x flow control frames on both transmit and receive sides.

On the receive side, if the KSZ8873MLL/FLL/RLL receives a pause control frame, the KSZ8873MLL/FLL/RLL will not

transmit the next normal frame until the timer, specified in the pause control frame, expires. If another pause frame is

received before the current timer expires, the timer will be updated with the new value in the second pause frame. During

this period (while it is flow controlled), only flow control packets from the KSZ8873MLL/FLL/RLL are transmitted.

On the transmit side, the KSZ8873MLL/FLL/RLL has intelligent and efficient ways to determine when to invoke flow con-

trol. The flow control is based on availability of the system resources, including available buffers, available transmit

queues, and available receive queues.

The KSZ8873MLL/FLL/RLL will flow control a port that has just received a packet if the destination port resource is busy.

The KSZ8873MLL/FLL/RLL issues a flow control frame (XOFF), containing the maximum pause time defined by the

IEEE 802.3x standard. Once the resource is freed up, the KSZ8873MLL/FLL/RLL sends out the other flow control frame

(XON) with zero pause time to turn off the flow control (turn on transmission to the port). A hysteresis feature is provided

to prevent the flow control mechanism from being constantly activated and deactivated.

The KSZ8873MLL/FLL/RLL flow controls all ports if the receive queue becomes full.

3.3.7.6 Half-Duplex Backpressure

A half-duplex backpressure option (not in IEEE 802.3 standards) is also provided. The activation and deactivation con-

ditions are the same as full-duplex flow control. If backpressure is required, the KSZ8873MLL/FLL/RLL sends pream-

bles to defer the other stations' transmission (carrier sense deference).

To avoid jabber and excessive deference (as defined in the 802.3 standard), after a certain time, the KSZ8873MLL/FLL/

RLL discontinues the carrier sense and then raises it again quickly. This short silent time (no carrier sense) prevents

other stations from sending out packets thus keeping other stations in a carrier sense deferred state. If the port has pack-

ets to send during a backpressure situation, the carrier sense type backpressure is interrupted and those packets are

transmitted instead. If there are no additional packets to send, carrier sense type backpressure is reactivated again until

switch resources free up. If a collision occurs, the binary exponential back-off algorithm is skipped and carrier sense is

generated immediately, thus reducing the chance of further collisions and carrier sense is maintained to prevent packet

reception.

To ensure no packet loss in 10BASE-T or 100BASE-TX half-duplex modes, the user must enable the following:

• Aggressive back-off (register 3 (0x03), bit [0])

• No excessive collision drop (register 4 (0x04), bit [3])

Note that these bits are not set as defaults because this is not the IEEE standard.

3.3.7.7 Broadcast Storm Protection

The KSZ8873MLL/FLL/RLL has an intelligent option to protect the switch system from receiving too many broadcast

packets. As the broadcast packets are forwarded to all ports except the source port, an excessive number of switch

resources (bandwidth and available space in transmit queues) may be utilized. The KSZ8873MLL/FLL/RLL has the

option to include “multicast packets” for storm control. The broadcast storm rate parameters are programmed globally,

and can be enabled or disabled on a per port basis. The rate is based on a 67 ms interval for 100BT and a 500 ms

interval for 10BT. At the beginning of each interval, the counter is cleared to zero, and the rate limit mechanism starts

to count the number of bytes during the interval. The rate definition is described in register 6 (0x06) and 7 (0x07). The

default setting is 0x63 (99 decimal). This is equal to a rate of 1%, calculated as follows:

148,800 frames/sec × 67 ms/interval × 1% = 99 frames/interval (approx.) = 0x63

Note: 148,800 frames/sec is based on 64-byte block of packets in 100BASE-TX with 12 bytes of IPG and 8 bytes of

preamble between two packets.

 2017 Microchip Technology Inc. DS00002348A-page 23

KSZ8873MLL/FLL/RLL

3.3.7.8 Port Individual MAC Address and Source Port Filtering

The KSZ8873MLL/FLL/RLL provide individual MAC address for port 1 and port 2 respectively. They can be set at reg-

ister 142-147 and 148-153. With this feature, the CPU connected to the port 3 can receive the packets from two internet

subnets which has their own MAC address.

The packet will be filtered if its source address matches the MAC address of port 1 or port 2 when the register 21 and

37 bit 6 is set to 1 respectively. For example, the packet will be dropped after it completes the loop of a ring network.

3.3.8 MII INTERFACE OPERATION

The Media Independent Interface (MII) is specified in Clause 22 of the IEEE 802.3u Standard. It provides a common

interface between physical layer and MAC layer devices. The MII provided by the KSZ8873MLL/FLL is connected to

the device’s third MAC. The interface contains two distinct groups of signals: one for transmission and the other for

reception. Tabl e 3- 4 describes the signals used by the MII bus.

The MII operates in either PHY mode or MAC mode. The data interface is a nibble wide and runs at ¼ the network bit

rate (not encoded). Additional signals on the transmit side indicate when data is valid or when an error occurs during

transmission. Similarly, the receive side has signals that convey when the data is valid and without physical layer errors.

For half-duplex operation, the SCOL signal indicates if a collision has occurred during transmission.

The KSZ8873MLL/FLL does not provide the MRXER signal for PHY mode operation and the MTXER signal for MAC

mode operation. Normally, MRXER indicates a receive error coming from the physical layer device and MTXER indi-

cates a transmit error from the MAC device. Because the switch filters error frames, these MII error signals are not used

by the KSZ8873MLL/FLL. So, for PHY mode operation, if the device interfacing with the KSZ8873MLL/FLL has an

MRXER input pin, it needs to be tied low. And, for MAC mode operation, if the device interfacing with the KSZ8873MLL/

FLL has an MTXER input pin, it also needs to be tied low.

The KSZ8873MLL/FLL provides a bypass feature in the MII PHY mode. Pin SMTXER3/MII_LINK is used for MII link

status. If the host is power down, pin MII_LINK will go to high. In this case, no new ingress frames from port1 or port 2

will be sent out through port 3, and the frames for port 3 already in packet memory will be flushed out.

3.3.9 RMII INTERFACE OPERATION

The Reduced Media Independent Interface (RMII) specifies a low pin count Media Independent Interface (MII). RMII

provides a common interface between physical layer and MAC layer devices, and has the following key characteristics:

• Ports 10 Mbps and 100 Mbps data rates.

TABLE 3-4: MII SIGNALS

PHY Mode Connections

Pin Description

MAC Mode Connections

External MAC

Controller Signals KSZ8873MLL/FLL

PHY Signals External PHY

Signals KSZ8873MLL/FLL

MAC Signals

MTXEN SMTXEN3 Transmit Enable MTXEN SMRXDV3

MTXER SMTXER3 Transmit Error MTXER (NOT USED)

MTXD3 SMTXD33 Transmit Data Bit 3 MTXD3 SMRXD33

MTXD2 SMTXD32 Transmit Data Bit 2 MTXD2 SMRXD32

MTXD1 SMTXD31 Transmit Data Bit 1 MTXD1 SMRXD31

MTXD0 SMTXD30 Transmit Data Bit 0 MTXD0 SMRXD30

MTXC SMTXC3 Transmit Clock MTXC SMRXC3

MCOL SCOL3 Collision Detection MCOL SCOL3

MCRS SCRS3 Carrier Sense MCRS SCRS3

MRXDV SMRXDV3 Receive Data Valid MRXDV SMTXEN3

MRXER (NOT USED) Receive Error MRXER SMTXER3

MRXD3 SMRXD33 Receive Data Bit 3 MRXD3 SMTXD33

MRXD2 SMRXD32 Receive Data Bit 2 MRXD2 SMTXD32

MRXD1 SMRXD31 Receive Data Bit 1 MRXD1 SMTXD31

MRXD0 SMRXD30 Receive Data Bit 0 MRXD0 SMTXD30

MRXC SMRXC3 Receive Clock MRXC SMTXC3

KSZ8873MLL/FLL/RLL

DS00002348A-page 24  2017 Microchip Technology Inc.

• Uses a single 50 MHz clock reference (provided internally or externally).

• Provides independent 2-bit wide (di-bit) transmit and receive data paths.

• Contains two distinct groups of signals: one for transmission and the other for reception

When EN_REFCLKO_3 is high, KSZ8873RLL will output a 50 MHz in REFCLKO_3. Register 198 bit[3] is used to select

internal or external reference clock. Internal reference clock means that the clock for the RMII of KSZ8873RLL will be

provided by the KSZ8873RLL internally and the REFCLKI_3 pin is unconnected. For the external reference clock, the

clock will provide to KSZ8873RLL via REFCLKI_3.

If the reference clock is not provided by the KSZ8873RLL, this 50 MHz reference clock has to be used in X1 pin instead

of the 25 MHz crystal because the clock skew of these two clock sources will impact the RMII timing. The SPIQ clock

selection strapping option pin is connected to low to select the 50 MHz input.

If the reference clock is provided by the KSZ8873RLL, set register 54[7]=1 to invert the RMII reference clock to meet

the timing specification in the worst cases.

The RMII provided by the KSZ8873RLL is connected to the device’s third MAC. It complies with the RMII Specification.

Table 3-6 describes the signals used by the RMII bus. Refer to RMII Specification for full detail on the signal description.

TABLE 3-5: RMII CLOCK SETTING

Reg. 198

Bit[3]

Pin 20 SMTXD33/

EN_REFCLKO_3

Internal Pull-Up

Pin 39 SPIQ

Internal Pull-Up Clock Source Note

(pull down by 1 k)

External 50 MHz OSC input to

SMTXC3/REFCLKI_3 and X1

pin directly

EN_REFCLKO_3 = 0 to

Disable REFCLKO_3 for

better EMI

01 0

(pull down by 1 k)

50 MHz on X1 pin is as clock

source. REFCLKO_3 Output Is

Feedback to REFCLKI_3

externally

EN_REFCLKO_3 = 1 to

Enable REFCLKO_3

01 1

25 MHz on X1 pin is as clock

source. REFCLKO_3 Output is

connected to REFCLKI_3

externally

EN_REFCLKO_3 = 1 to

Enable REFCLKO_3

11 0

50 MHz on X1 pin, 50 MHz RMII

Clock goes to SMTXC3/ REF-

CLKI_3 internally.

REFCLKI_3 can be pulled down

by a resistor.

EN_REFCLKO_3 = 1 to

Enable REFCLKO_3 and

no feedback to

REFCLKI_3

11 1

25 MHz on X1 pin, 50 MHz RMII

Clock goes to SMTXC3/ REF-

CLKI_3 internally.

REFCLKI_3 can be pulled down

by a resistor.

EN_REFCLKO_3 = 1 to

Enable REFCLKO_3 and

no feedback to

REFCLKI_3

TABLE 3-6: RMII SIGNAL DESCRIPTION

RMII Signal Na m e Direction (with

respect to PHY) Direction (with

respect to MAC) RMII Signal

Description KSZ8873RLL RMII

Signal Direction

REF_CLK Input Input or Output

Synchronous 50 MHz

clock reference for

receive, transmit, and

control interface

REFCLKI_3 (input)

CRS_DV Output Input Carrier sense/

Receive data valid SMRXDV3 (output)

RXD1 Output Input Receive data bit 1 SMRXD31 (output)

RXD0 Output Input Receive data bit 0 SMRXD30 (output)

TX_EN Input Output Transmit enable SMTXEN3 (input)

TXD1 Input Output Transmit data bit 1 SMTXD31 (input)

 2017 Microchip Technology Inc. DS00002348A-page 25

KSZ8873MLL/FLL/RLL

The KSZ8873RLL filters error frames and, thus, does not implement the RX_ER output signal. To detect error frames

from RMII PHY devices, the SMTXER3 input signal of the KSZ8873RLL is connected to the RXER output signal of the

RMII PHY device.

Collision detection is implemented in accordance with the RMII Specification.

In RMII mode, tie MII signals SMTXD3[3:2] and SMTXER3 to ground if they are not used.

The KSZ8873RLL RMII can interface with RMII PHY and RMII MAC devices. The latter allows two KSZ8873RLL

devices to be connected back-to-back. Ta b le 3 - 7 shows the KSZ8873RLL RMII pin connections with an external RMII

PHY and an external RMII MAC, such as another KSZ8873RLL device.

3.3.10 MII MANAGEMENT (MIIM) INTERFACE

The KSZ8873MLL/FLL/RLL supports the IEEE 802.3 MII Management Interface, also known as the Management Data

Input/Output (MDIO) Interface. This interface allows upper-layer devices to monitor and control the states of the

KSZ8873MLL/FLL/RLL. An external device with MDC/MDIO capability is used to read the PHY status or configure the

PHY settings. Further detail on the MIIM interface is found in Clause 22.2.4.5 of the IEEE 802.3u Specification and refer

to 802.3 section 22.3.4 for the timing.

The MIIM interface consists of the following:

• A physical connection that incorporates the data line (SDA_MDIO) and the clock line (SCL_MDC).

• A specific protocol that operates across the aforementioned physical connection that allows an external controller

to communicate with the KSZ8873MLL/FLL/RLL device.

• Access to a set of eight 16-bit registers, consisting of six standard MIIM registers [0:5] and two custom MIIM regis-

ters [29, 31].

The MIIM Interface can operate up to a maximum clock speed of 5 MHz.

Table 3-8 depicts the MII Management Interface frame format.

TXD0 Input Output Transmit data bit 0 SMTXD30 (input)

RX_ER Output Input (not required) Receive error (not used)

————

SMTXER3 (input)

Connects to RX_ER

signal of RMII PHY

device

TABLE 3-7: RMII SIGNAL CONNECTIONS

KSZ8873RLL

PHY-MAC Connections Pin Descriptions

KSZ8873RLL

MAC-MAC Connections

External PHY

Signals KSZ8873RLL MAC

Signals External MAC

Signals

REF_CLK REFCLKI_3 Reference Clock REFCLKI_3 REF_CLK

TX_EN SMRXDV3 Carrier sense/

Receive data valid SMRXDV3 CRS_DV

TXD1 SMRXD31 Receive data bit 1 SMRXD31 RXD1

TXD0 SMRXD30 Receive data bit 0 SMRXD30 RXD0

CRS_DV SMTXEN3 Transmit enable SMTXEN3 TX_EN

RXD1 SMTXD31 Transmit data bit 1 SMTXD31 TXD1

RXD0 SMTXD30 Transmit data bit 0 SMTXD30 TXD0

RX_ER SMTXER3 Receive error (not used) (not used)

TABLE 3-6: RMII SIGNAL DESCRIPTION (CONTINUED)

RMII Signal Na m e Direction (with

respect to PHY) Direction (with

respect to MAC) RMII Signal

Description KSZ8873RLL RMII

Signal Direction

KSZ8873MLL/FLL/RLL

DS00002348A-page 26  2017 Microchip Technology Inc.

3.3.11 SERIAL MANAGEMENT INTERFACE (SMI)

The SMI is the KSZ8873MLL/FLL/RLL non-standard MIIM interface that provides access to all KSZ8873MLL/FLL/RLL

configuration registers. This interface allows an external device to completely monitor and control the states of the

KSZ8873MLL/FLL/RLL.

The SMI interface consists of the following:

• A physical connection that incorporates the data line (SDA_MDIO) and the clock line (SCL_MDC).

• A specific protocol that operates across the aforementioned physical connection that allows an external controller

to communicate with the KSZ8873MLL/FLL/RLL device.

• Access to all KSZ8873MLL/FLL/RLL configuration registers. Register access includes the Global, Port and

Advanced Control Registers 0-198 (0x00 – 0xC6), and indirect access to the standard MIIM registers [0:5] and

custom MIIM registers [29, 31].

Table 3-9 depicts the SMI frame format.

SMI register read access is selected when OP Code is set to “00” and bit 4 of the PHY address is set to ‘1’. SMI register

write access is selected when OP Code is set to “00” and bit 4 of the PHY address is set to ‘0’. PHY address bit[3] is

undefined for SMI register access, and hence can be set to either ‘0’ or ‘1’ in read/write operations.

To access the KSZ8873MLL/FLL/RLL registers 0-196 (0x00 – 0xC6), the following applies:

• PHYAD[2:0] and REGAD[4:0] are concatenated to form the 8-bit address; that is, {PHYAD[2:0], REGAD[4:0]} =

bits [7:0] of the 8-bit address.

• TA bits [1:0] are ‘Z0’ means the processor MDIO pin is changed to input Hi-Z from output mode and the followed

‘0’ is the read response from device.

• TA bits [1:0] are set to ‘10’ when write registers.

• Registers are 8 data bits wide.

- For read operation, data bits [15:8] are read back as 0’s.

- For write operation, data bits [15:8] are not defined, and hence can be set to either ‘0’ or ‘1’.

SMI register access is the same as the MIIM register access, except for the register access requirements presented in

this section.

3.4 Advanced Switch Functions

3.4.1 BYPASS MODE

The KSZ8873MLL/FLL/RLL also offers a bypass mode that enables system-level power saving. When the CPU (con-

nected to Port 3) enters a power saving mode of power down or sleeping mode, the CPU can control pin 27 SMTXER3/

MII_LINK_3, which can be tied high so that the KSZ8873MLL/FLL/RLL detects this change and automatically switches

to the bypass mode. In this mode, the switch function between Port 1 and Port 2 is sustained. The packets with DA to

Port 3 will be dropped and will bypass the internal buffer memory, making the buffer memory more efficient for the data

transfer between Port 1 and Port 2.

TABLE 3-8: MII MANAGEMENT FRAME FORMAT

Preamble Start of

Frame

Read/

Write OP

Code

PHY

Address

Bits[4:0]

REG

Address

Bits[4:0] TA Data Bits[15:0] Idle

Read 32 1’s 01 10 AAAAA RRRRR Z0 DDDDDDDD_DDDDDDDD Z

Write 32 1’s 01 01 AAAAA RRRRR 10 DDDDDDDD_DDDDDDDD Z

TABLE 3-9: SERIAL MANAGEMENT INTERFACE (SMI) FRAME FORMAT

Preamble Start of

Frame

Read/

Write OP

Code

PHY

Address

Bits[4:0]

REG

Address

Bits[4:0] TA Data Bits[15:0] Idle

Read 32 1’s 01 00 1xRRR RRRRR Z0 0000_0000_DDDD_DDDD Z

Write 32 1’s 01 00 0xRRR RRRRR 10 xxxx_xxxx_DDDD_DDDD Z

 2017 Microchip Technology Inc. DS00002348A-page 27

KSZ8873MLL/FLL/RLL

3.4.2 IEEE 802.1Q VLAN SUPPORT

The KSZ8873MLL/FLL/RLL supports 16 active VLANs out of the 4096 possible VLANs specified in the IEEE 802.1Q

specification. KSZ8873MLL/FLL/RLL provides a 16-entries VLAN table that converts the 12-bits VLAN ID (VID) to the

4-bits Filter ID (FID) for address lookup. If a non-tagged or null-VID-tagged packet is received, the ingress port default

VID is used for lookup. In VLAN mode, the lookup process starts with VLAN table lookup to determine whether the VID

is valid. If the VID is not valid, the packet is dropped and its address is not learned. If the VID is valid, the FID is retrieved

for further lookup. The FID + Destination Address (FID+DA) are used to determine the destination port. The FID +

Source Address (FID+SA) are used for address learning.

Advanced VLAN features, such as “Ingress VLAN filtering” and “Discard Non PVID packets” are also supported by the

KSZ8873MLL/FLL/RLL. These features can be set on a per port basis, and are defined in registers 18, 34, and 50 for

ports 1, 2 and 3, respectively.

3.4.3 QOS PRIORITY SUPPORT

The KSZ8873MLL/FLL/RLL provides Quality of Service (QoS) for applications such as VoIP and video conferencing.

Offering four priority queues per port, the per-port transmit queue can be split into four priority queues: Queue 3 is the

highest priority queue and Queue 0 is the lowest priority queue. Bit [0] of registers 16, 32, and 48 is used to enable split

transmit queues for ports 1, 2, and 3, respectively. If a port's transmit queue is not split, high priority and low priority

packets have equal priority in the transmit queue.

There is an additional option to either always deliver high priority packets first or use weighted fair queuing for the four

priority queues. This global option is set and explained in bit [3] of register 5.

3.4.4 PORT-BASED PRIORITY

With port-based priority, each ingress port is individually classified as a high priority receiving port. All packets received

at the high priority receiving port are marked as high priority and are sent to the high-priority transmit queue if the cor-

responding transmit queue is split. Bits [4:3] of registers 16, 32, and 48 are used to enable port-based priority for ports

1, 2, and 3, respectively.

TABLE 3-10: FID+DA LOOKUP IN VLAN MODE

DA Found in

Static MAC

Table?

Use FID

Flag? FID Match? FID+DA Found in

Dynamic MA C

Table? Action

No Don’t care Don’t care No Broadcast to the membership ports

defined in the VLAN Table bits [18:16]

No Don’t care Don’t care Yes

Send to the destination port defined in

the Dynamic MAC Address Table bits

[53:52]

Yes 0 Don’t care Don’t care

Send to the destination port(s) defined

in the Static MAC Address Table bits

[50:48]

Yes 1 No No Broadcast to the membership ports

defined in the VLAN Table bits [18:16]

Yes 1 No Yes

Send to the destination port defined in

the Dynamic MAC Address Table bits

[53:52]

Yes 1 Yes Do n’ t care

Send to the destination port(s) defined

in the Static MAC Address Table bits

[50:48]

TABLE 3-11: FID+SA LOOKUP IN VLAN MODE

FID+SA Found in Dynamic MAC Table? Action

No Learn and add FID+SA to the Dynamic MAC Address Table

Yes Update time stamp

KSZ8873MLL/FLL/RLL

DS00002348A-page 28  2017 Microchip Technology Inc.

3.4.5 802.1P-BASED PRIORITY

For 802.1p-based priority, the KSZ8873MLL/FLL/RLL examines the ingress (incoming) packets to determine whether

they are tagged. If tagged, the 3-bit priority field in the VLAN tag is retrieved and compared against the “priority mapping”

value, as specified by the registers 12 and 13. The “priority mapping” value is programmable.

Figure 3-6 illustrates how the 802.1p priority field is embedded in the 802.1Q VLAN tag.

802.1p-based priority is enabled by bit [5] of registers 16, 32, and 48 for ports 1, 2, and 3, respectively.

The KSZ8873MLL/FLL/RLL provides the option to insert or remove the priority tagged frame's header at each individual

egress port. This header, consisting of the 2 bytes VLAN Protocol ID (VPID) and the 2-byte Tag Control Information field

(TCI), is also referred to as the IEEE 802.1Q VLAN tag.

Tag Insertion is enabled by bit [2] of the port registers control 0 and the register 194 to select which source port (ingress

port) PVID can be inserted on the egress port for ports 1, 2, and 3, respectively. At the egress port, untagged packets

are tagged with the ingress port’s default tag. The default tags are programmed in register sets {19,20}, {35,36}, and

{51,52} for ports 1, 2, and 3, respectively, and the source port VID has to be inserted at selected egress ports by bit[5:0]

of register 194. The KSZ8873MLL/FLL/RLL will not add tags to already tagged packets.

Tag Removal is enabled by bit [1] of registers 16, 32, and 48 for ports 1, 2, and 3, respectively. At the egress port, tagged

packets will have their 802.1Q VLAN Tags removed. The KSZ8873MLL/FLL/RLL will not modify untagged packets.

The CRC is recalculated for both tag insertion and tag removal.

802.1p Priority Field Re-mapping is a QoS feature that allows the KSZ8873MLL/FLL/RLL to set the “User Priority Ceil-

ing” at any ingress port. If the ingress packet’s priority field has a higher priority value than the default tag’s priority field

of the ingress port, the packet’s priority field is replaced with the default tag’s priority field.

3.4.6 DIFFSERV-BASED PRIORITY

DiffServ-based priority uses the ToS registers (registers 96 to 111) in the Advanced Control Registers section. The ToS

priority control registers implement a fully decoded, 64-bit Differentiated Services Code Point (DSCP) register to deter-

mine packet priority from the 6-bit ToS field in the IP header. When the most significant 6 bits of the ToS field are fully

decoded, the resultant of the 64 possibilities is compared with the corresponding bits in the DSCP register to determine

priority.

3.5 Spanning Tree Support

To support spanning tree, port 3 is designated as the processor port.

The other ports (port 1 and port 2) can be configured in one of the five spanning tree states via “transmit enable”, “receive

enable” and “learning disable” register settings in registers 18 and 34 for ports 1 and 2, respectively. The following table

shows the port setting and software actions taken for each of the five spanning tree states.

FIGURE 3-6: 802.1P PRIORITY FIELD FORMAT

Preamble DA TCI

866 2

length LLC Data FCS

2 46-1500 4

Tagged Packet Type

(8100 for Ethernet) 802.1p

CFI

VLAN ID

Bytes

Bits 16 3 12

802.1q VLAN Tag

SA VPID

 2017 Microchip Technology Inc. DS00002348A-page 29

KSZ8873MLL/FLL/RLL

3.6 Rapid Spanning Tree Support

There are three operational states of the Discarding, Learning, and Forwarding assigned to each port for RSTP:

Discarding ports do not participate in the active topology and do not learn MAC addresses.

Discarding state: the state includes three states of the disable, blocking and listening of STP.

Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1."

Software action: the processor should not send any packets to the port. The switch may still send specific packets to

the processor (packets that match some entries in the static table with “overriding bit” set) and the processor should

discard those packets. When disable the port’s learning capability (learning disable=’1’), set the register 2 bit 5 and bit

4 will flush rapidly the port related entries in the dynamic MAC table and static MAC table.

Note: processor is connected to port 3 via MII interface. Address learning is disabled on the port in this state.

Ports in Learning states learn MAC addresses, but do not forward user traffic.

TABLE 3-12: SPANNING TREE STATES

Disable State Port Setting Software Action

The port should not forward or

receive any packets. Learn-

ing is disabled.

“transmit enable = 0,

receive enable = 0,

learning disable =1”

The processor should not send any packets to the port. The

switch may still send specific packets to the processor

(packets that match some entries in the “static MAC table”

with “overriding bit” set) and the processor should discard

those packets. Address learning is disabled on the port in

this state.

Blocking State Port Setting Software Action

Only packets to the processor

are forwarded. Learning is

disabled.

“transmit enable = 0,

receive enable = 0,

learning disable =1”

The processor should not send any packets to the port(s) in

this state. The processor should program the “Static MAC

table” with the entries that it needs to receive (for example,

BPDU packets). The “overriding” bit should also be set so

that the switch will forward those specific packets to the pro-

cessor. Address learning is disabled on the port in this state.

Listening State Port Setting Software Action

Only packets to and from the

processor are forwarded.

Learning is disabled.

“transmit enable = 0,

receive enable = 0,

learning disable =1”

The processor should program the “Static MAC table” with

the entries that it needs to receive (for example, BPDU

packets). The “overriding” bit should be set so that the

switch will forward those specific packets to the processor.

The processor may send packets to the port(s) in this state.

See “Tail Tagging Mode” for details. Address learning is dis-

abled on the port in this state.

Learning State Port Setting Software Action

Only packets to and from the

processor are forwarded.

Learning is enabled.

“transmit enable = 0,

receive enable = 0,

learning disable = 0”

The processor should program the “Static MAC table” with

the entries that it needs to receive (for example, BPDU

packets). The “overriding” bit should be set so that the

switch will forward those specific packets to the processor.

The processor may send packets to the port(s) in this state.

See “Tail Tagging Mode” for details. Address learning is

enabled on the port in this state.

Forwarding State Port Setting Software Action

Packets are forwarded and

received normally. Learning is

enabled.

“transmit enable = 1,

receive enable = 1,

learning disable = 0”

The processor programs the “Static MAC table” with the

entries that it needs to receive (for example, BPDU pack-

ets). The “overriding” bit is set so that the switch forwards

those specific packets to the processor. The processor can

send packets to the port(s) in this state. See “Tail Tagging

Mode” for details. Address learning is enabled on the port in

this state.

KSZ8873MLL/FLL/RLL

DS00002348A-page 30  2017 Microchip Technology Inc.

Learning state: only packets to and from the processor are forwarded. Learning is enabled.

Port setting: “transmit enable = 0, receive enable = 0, learning disable = 0.”

Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g., BPDU

packets). The “overriding” bit should be set so that the switch will forward those specific packets to the processor. The

processor may send packets to the port(s) in this state, see “Tail Tagging Mode” section for details. Address learning is

enabled on the port in this state.

Ports in Forwarding states fully participate in both data forwarding and MAC learning.

Forwarding state: packets are forwarded and received normally. Learning is enabled.

Port setting: “transmit enable = 1, receive enable = 1, learning disable = 0.”

Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g., BPDU

packets). The “overriding” bit should be set so that the switch will forward those specific packets to the processor. The

processor may send packets to the port(s) in this state, see “Tail Tagging Mode” section for details. Address learning is

enabled on the port in this state.

RSTP uses only one type of BPDU called RSTP BPDUs. They are similar to STP Configuration BPDUs with the excep-

tion of a type field set to “version 2” for RSTP and “version 0” for STP, and a flag field carrying additional information.

3.7 Tail Tagging Mode

The Tail Tag is only seen and used by the port 3 interface, which should be connected to a processor. It is an effective

way to retrieve the ingress port information for spanning tree protocol IGMP snooping and other applications. The Bit 1

and bit 0 in the one byte tail tagging is used to indicate the source/destination port in port 3. Bit 3 and bit 2 are used for

the priority setting of the ingress frame in port 3. Other bits are not used. The Tail Tag feature is enable by setting register

3 bit 6.

FIGURE 3-7: TAIL TAG FRAME FORMAT

TABLE 3-13: TAIL TAG RULES

Ingress to Port 3 (Host to KSZ8873)

Bit [1,0] Destination Port

0,0 Normal (address lookup)

0,1 Port 1

1,0 Port 2

1,1 Port 1 and 2

Bit [3,2] Frame Priority

0,0 Priority 0

0,1 Priority 1

1,0 Priority 2

1,1 Priority 3

Egress from Port 3 (KSZ8873 to Host)

Bit [0] Source Port

0Port 1

1Port 2

Preamble DA TCI

866 2

length LLC Data Tail Tag

2 46-1500 1

FCS

Bytes 2

SA VPID

 2017 Microchip Technology Inc. DS00002348A-page 31

KSZ8873MLL/FLL/RLL

3.8 IGMP Support

For Internet Group Management Protocol (IGMP) support in layer 2, the KSZ8873MLL/FLL/RLL provides two compo-

nents: IGMP snooping and IGMP send-back to the subscribed port.

3.8.1 IGMP SNOOPING

The KSZ8873MLL/FLL/RLL traps IGMP packets and forwards them only to the processor (port 3). The IGMP packets

are identified as IP packets (either Ethernet IP packets, or IEEE 802.3 SNAP IP packets) with IP version = 0x4 and pro-

tocol version number = 0x2.

3.8.2 IGMP SEND-BACK TO THE SUBSCRIBED PORT

Once the host responds the received IGMP packet, the host should know the original IGMP ingress port and send back

the IGMP packet to this port only, otherwise this IGMP packet will be broadcasted to all ports to downgrade the perfor-

mance.

Enable the tail tag mode, the host will know the IGMP packet received port from tail tag bits [0] and can send back the

response IGMP packet to this subscribed port by setting the bits [1,0] in the tail tag. Enable “Tail tag mode” by setting

3.9 Port Mirroring Support

KSZ8873MLL/FLL/RLL supports “Port Mirroring” comprehensively as:

• “Receive only” mirror on a port

- All the packets received on the port are mirrored on the sniffer port. For example, port 1 is programmed to be

“receive sniff” and port 3 is programmed to be the “sniffer port”. A packet received on port 1 is destined to port

2 after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 2 and port 3. The

KSZ8873MLL/FLL/RLL can optionally even forward “bad” received packets to the “sniffer port”.

• “Transmit only” mirror on a port

- All the packets transmitted on the port are mirrored on the sniffer port. For example, port 1 is programmed to

be “transmit sniff” and port 3 is programmed to be the “sniffer port”. A packet received on port 2 is destined to

port 1 after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 1 and port 3.

• “Receive and transmit” mirror on two ports

- All the packets received on port A and transmitted on port B are mirrored on the sniffer port. To turn on the

“AND” feature, set register 5 bit [0] to ‘1’. For example, port 1 is programmed to be “receive sniff”, port 2 is

programmed to be “transmit sniff”, and port 3 is programmed to be the “sniffer port”. A packet received on port

1 is destined to port 2 after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 2

and port 3.

Multiple ports can be selected as “receive sniff” or “transmit sniff”. In addition, any port can be selected as the “sniffer

port”. All these per port features can be selected through registers 17, 33, and 49 for ports 1, 2, and 3, respectively.

3.10 Rate Limiting Support

The KSZ8873MLL/FLL/RLL provides a fine resolution hardware rate limiting from 64 kbps to 99 Mbps. The rate step is

64 kbps when the rate range is from 64 kbps to 960 kbps and 1 Mbps for 1 Mbps to 100 Mbps (100BT) or to 10 Mbps

(10BT) (refer to Data Rate Limit Table). The rate limit is independently on the “receive side” and on the “transmit side”

on a per port basis. For 10BASE-T, a rate setting above 10 Mbps means the rate is not limited. On the receive side, the

data receive rate for each priority at each port can be limited by setting up Ingress Rate Control Registers. On the trans-

mit side, the data transmit rate for each priority queue at each port can be limited by setting up Egress Rate Control

Registers. The size of each frame has options to include minimum IFG (Inter Frame Gap) or Preamble byte, in addition

to the data field (from packet DA to FCS).

For ingress rate limiting, KSZ8873MLL/FLL/RLL provides options to selectively choose frames from all types, multicast,

broadcast, and flooded unicast frames. The KSZ8873MLL/FLL/RLL counts the data rate from those selected type of

frames. Packets are dropped at the ingress port when the data rate exceeds the specified rate limit.

For egress rate limiting, the Leaky Bucket algorithm is applied to each output priority queue for shaping output traffic.

Inter frame gap is stretched on a per frame base to generate smooth, non-burst egress traffic. The throughput of each

output priority queue is limited by the egress rate specified.

KSZ8873MLL/FLL/RLL

DS00002348A-page 32  2017 Microchip Technology Inc.

If any egress queue receives more traffic than the specified egress rate throughput, packets may be accumulated in the

output queue and packet memory. After the memory of the queue or the port is used up, packet dropping or flow control

will be triggered. As a result of congestion, the actual egress rate may be dominated by flow control/dropping at the

ingress end, and may be therefore slightly less than the specified egress rate.

To reduce congestion, it is a good practice to make sure the egress bandwidth exceeds the ingress bandwidth.

3.11 Unicast MAC Address Filtering

The unicast MAC address filtering function works in conjunction with the static MAC address table. First, the static MAC

address table is used to assign a dedicated MAC address to a specific port. If a unicast MAC address is not recorded

in the static table, it is also not learned in the dynamic MAC table. The KSZ8873MLL/FLL/RLL is then configured with

the option to either filter or forward unicast packets for an unknown MAC address. This option is enabled and configured

in register 14.

This function is useful in preventing the broadcast of unicast packets that could degrade the quality of the port in appli-

cations such as voice over Internet Protocol (VoIP).

3.12 Configuration Interface

The KSZ8873MLL/FLL/RLL can operate as both a managed switch and an unmanaged switch.

In unmanaged mode, the KSZ8873MLL/FLL/RLL is typically programmed using an EEPROM. If no EEPROM is present,

the KSZ8873MLL/FLL/RLL is configured using its default register settings. Some default settings are configured via

strap-in pin options. The strap-in pins are indicated in the “Pin Description and I/O Assignment” table.

3.12.1 I2C MASTER SERIAL BUS CONFIGURATION

With an additional I2C (“2-wire”) EEPROM, the KSZ8873MLL/FLL/RLL can perform more advanced switch features like

“broadcast storm protection” and “rate control” without the need of an external processor.

For KSZ8873MLL/FLL/RLL I2C Master configuration, the EEPROM stores the configuration data for register 0 to regis-

ter 120 (as defined in the KSZ8873MLL/FLL/RLL register map) with the exception of the “Read Only” status registers.

After the de-assertion of reset, the KSZ8873MLL/FLL/RLL sequentially reads in the configuration data for all control reg-

isters, starting from register 0.

The following is a sample procedure for programming the KSZ8873MLL/FLL/RLL with a pre-configured EEPROM:

1. Connect the KSZ8873MLL/FLL/RLL to the EEPROM by joining the SCL and SDA signals of the respective

devices.

2. Enable I2C master mode by setting the KSZ8873MLL/FLL/RLL strap-in pins, P2LED[1:0] to “00”.

3. Check to ensure that the KSZ8873MLL/FLL/RLL reset signal input, RSTN, is properly connected to the external

reset source at the board level.

4. Program the desired configuration data into the EEPROM.

FIGURE 3-8: EEPROM CONFIGURATION TIMING DIAGRAM

....

RST_N

SCL

SDA

prgm

<15 ms

 2017 Microchip Technology Inc. DS00002348A-page 33

KSZ8873MLL/FLL/RLL

5. Place the EEPROM on the board and power up the board.

6. Assert an active-low reset to the RSTN pin of the KSZ8873MLL/FLL/RLL. After reset is de-asserted, the

KSZ8873MLL/FLL/RLL begins reading the configuration data from the EEPROM. The KSZ8873MLL/FLL/RLL

checks that the first byte read from the EEPROM is “88”. If this value is correct, EEPROM configuration contin-

ues. If not, EEPROM configuration access is denied and all other data sent from the EEPROM is ignored by the

KSZ8873MLL/FLL/RLL.

For proper operation, ensure that the KSZ8873MLL/FLL/RLL PWRDN input signal is not asserted during the reset oper-

ation. The PWRDN input is active-low.

3.12.2 I2C SLAVE SERIAL BUS CONFIGURATION

In managed mode, the KSZ8873MLL/FLL/RLL can be configured as an I2C slave device. In this mode, an I2C master

device (external controller/CPU) has complete programming access to the KSZ8873MLL/FLL/RLL’s 198 registers. Pro-

gramming access includes the Global Registers, Port Registers, Advanced Control Registers and indirect access to the

“Static MAC Table”, “VLAN Table”, “Dynamic MAC Table,” and “MIB Counters.” The tables and counters are indirectly

accessed via registers 121 to 131.

In I2C slave mode, the KSZ8873MLL/FLL/RLL operates like other I2C slave devices. Addressing the KSZ8873MLL/FLL/

RLL’s 8-bit registers is similar to addressing the Microchip AT24C02 EEPROM’s memory locations. Details of I2C read/

write operations and related timing information can be found in the AT24C02 data sheet.

Two fixed 8-bit device addresses are used to address the KSZ8873MLL/FLL/RLL in I2C slave mode. One is for read;

the other is for write. The addresses are as follow:

• 1011_1111 <read>

• 1011_1110 <write>

The following is a sample procedure for programming the KSZ8873MLL/FLL/RLL using the I2C slave serial bus:

1. Enable I2C slave mode by setting the KSZ8873MLL/FLL/RLL strap-in pins P2LED[1:0] to “01”.

2. Power up the board and assert reset to the KSZ8873MLL/FLL/RLL. Configure the desired register settings in the

KSZ8873MLL/FLL/RLL, using the I2C write operation.

3. Read back and verify the register settings in the KSZ8873MLL/FLL/RLL, using the I2C read operation.

Some of the configuration settings, such as “Aging Enable”, “Auto Negotiation Enable”, “Force Speed” and “Power

down” can be programmed after the switch has been started.

3.12.3 SPI SLAVE SERIAL BUS CONFIGURATION

In managed mode, the KSZ8873MLL/FLL/RLL can be configured as a SPI slave device. In this mode, a SPI master

device (external controller/CPU) has complete programming access to the KSZ8873MLL/FLL/RLL’s 198 registers. Pro-

gramming access includes the Global Registers, Port Registers, Advanced Control Registers, and indirect access to

the “Static MAC Table”, “VLAN Table”, “Dynamic MAC Table,” and “MIB Counters”. The tables and counters are indirectly

accessed via registers 121 to 131.

The KSZ8873MLL/FLL/RLL supports two standard SPI commands: ‘0000_0011’ for data read and ‘0000_0010’ for data

write. SPI multiple read and multiple write are also supported by the KSZ8873MLL/FLL/RLL to expedite register read

back and register configuration, respectively.

SPI multiple read is initiated when the master device continues to drive the KSZ8873MLL/FLL/RLL SPISN input pin (SPI

Slave Select signal) low after a byte (a register) is read. The KSZ8873MLL/FLL/RLL internal address counter increments

automatically to the next byte (next register) after the read. The next byte at the next register address is shifted out onto

the KSZ8873MLL/FLL/RLL SPIQ output pin. SPI multiple read continues until the SPI master device terminates it by de-

asserting the SPISN signal to the KSZ8873MLL/FLL/RLL.

Similarly, SPI multiple write is initiated when the master device continues to drive the KSZ8873MLL/FLL/RLL SPISN

input pin low after a byte (a register) is written. The KSZ8873MLL/FLL/RLL internal address counter increments auto-

matically to the next byte (next register) after the write. The next byte that is sent from the master device to the

KSZ8873MLL/FLL/RLL SDA input pin is written to the next register address. SPI multiple write continues until the SPI

master device terminates it by de-asserting the SPISN signal to the KSZ8873MLL/FLL/RLL.

For both SPI multiple read and multiple write, the KSZ8873MLL/FLL/RLL internal address counter wraps back to register

address zero once the highest register address is reached. This feature allows all 198 KSZ8873MLL/FLL/RLL registers

to be read, or written with a single SPI command from any initial register address.

The KSZ8873MLL/FLL/RLL is capable of supporting an SPI bus.

KSZ8873MLL/FLL/RLL

DS00002348A-page 34  2017 Microchip Technology Inc.

The following is a sample procedure for programming the KSZ8873MLL/FLL/RLL using the SPI bus:

1. At the board level, connect the KSZ8873MLL/FLL/RLL pins as follows:

2. Enable SPI slave mode by setting the KSZ8873MLL/FLL/RLL strap-in pins P2LED[1:0] to “10”.

3. Power up the board and assert reset to the KSZ8873MLL/FLL/RLL.

4. Configure the desired register settings in the KSZ8873MLL/FLL/RLL, using the SPI write or multiple write com-

mand.

5. Read back and verify the register settings in the KSZ8873MLL/FLL/RLL, using the SPI read or multiple read com-

mand.

Some of the configuration settings, such as “Aging Enable,” “Auto Negotiation Enable,” “Force Speed,” and “Power

Down” can be programmed after the switch has been started.

The following four figures illustrate the SPI data cycles for “Write,” “Read,” “Multiple Write,” and “Multiple Read.” The

read data is registered out of SPIQ on the falling edge of SPIC, and the data input on SPID is registered on the rising

edge of SPIC.

TABLE 3-14: SPI CONNECTIONS

Pin Number Signal Name External Processor Signal

Description

40 SPISN SPI Slave Select

42 SCL (SPIC) SPI Clock

43 SDA (SPID) SPI Data

(Master output; Slave input)

39 SPIQ SPI Data

(Master input; Slave output)

FIGURE 3-9: SPI WRITE DATA CYCLE

SPIQ

SPIC

SPID

SPIS_N

00000010XA7 A6 A5 A4 A3 A2 A1 A0

WRITE COMMAND WRITE ADDRESS WRITE DATA

D2 D0D1D3D4D5D6D7

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KSZ8873MLL/FLL/RLL

FIGURE 3-10: SPI READ DATA CYCLE

FIGURE 3-11: SPI MULTIPLE WRITE

SPIQ

SPIC

SPID

SPIS_N

00000010XA7 A6 A5 A4 A3 A2 A1 A0

READ COMMAND READ ADDRESS READ DATA

D2 D0D1D3D4D5D6D7

SPIQ

SPIC

SPID

SPIS_N

00000010XA7 A6 A5 A4 A3 A2 A1 A0

WRITE COMMAND WRITE ADDRESS Byte 1

D2 D0D1D3D4D5D6D7

SPIQ

SPIC

SPID

SPIS_N

D7 D6 D5 D4 D4 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

Byte 2 Byte 3 ... Byte N

D2 D0D1D3D4D5D6D7

KSZ8873MLL/FLL/RLL

DS00002348A-page 36  2017 Microchip Technology Inc.

3.13 Loopback Support

The KSZ8873MLL/FLL/RLL provides loopback support for remote diagnostic of failure. In loopback mode, the speed at

both PHY ports needs to be set to 100BASE-TX. Two types of loopback are supported: Far-end Loopback and Near-

end (Remote) Loopback.

3.13.1 FAR-END LOOPBACK

Far-end loopback is conducted between the KSZ8873MLL/FLL/RLL’s two PHY ports. The loopback is limited to few

package a time for diagnosis purpose and cannot support large traffic. The loopback path starts at the “Originating.”

PHY port’s receive inputs (RXP/RXM), wraps around at the “loopback” PHY port’s PMD/PMA, and ends at the “Origi-

nating” PHY port’s transmit outputs (TXP/TXM).

Bit [0] of registers 29 and 45 is used to enable far-end loopback for ports 1 and 2, respectively. Alternatively, the MII

Management register 0, bit [14] can be used to enable far-end loopback.

The far-end loopback path is illustrated in Figure 3-13.

FIGURE 3-12: SPI MULTIPLE READ

SPIQ

SPIC

SPID

SPIS_N

00000011XA7 A6 A5 A4 A3 A2 A1 A0

D7 D6 D5 D4 D3 D2 D1 D0

READ COMMAND READ ADDRESS Byte 1

XXXXXXXXXXXXXXXX

Byte 2 Byte 3 Byte N

X X X X X X X X

XXXXXXXX

D7 D6 D5 D4 D3 D2 D1 D0

D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

SPIQ

SPIC

SPID

SPIS_N

 2017 Microchip Technology Inc. DS00002348A-page 37

KSZ8873MLL/FLL/RLL

3.13.2 NEAR-END (REMOTE) LOOPBACK

Near-end (Remote) loopback is conducted at either PHY port 1 or PHY port 2 of the KSZ8873MLL/FLL/RLL. The loop-

back path starts at the PHY port’s receive inputs (RXPx/RXMx), wraps around at the same PHY port’s PMD/PMA, and

ends at the PHY port’s transmit outputs (TXPx/TXMx).

Bit [1] of registers 26 and 42 is used to enable near-end loopback for ports 1 and 2, respectively. Alternatively, the MII

Management register 31, bit [1] can be used to enable near-end loopback.

The near-end loopback paths are illustrated in Figure 3-14.

FIGURE 3-13: FAR-END LOOPBACK PATH

FIGURE 3-14: NEAR-END (REMOTE) LOOPBACK PATH

PMD/PMA

PCS

MAC

Switch

MAC

PCS

PMD/PMA

TXP /

TXM

RXP /

RXM Originating

PHY Port

Loop Back

PHY Port

TXP1/

TXM1

RXP1/

RXM1

RXP2/

RXM2

TXP2/

TXM2

PHY

Port 1

PHY

Port 2

PMD/PMA

PCS

MAC

Switch

MAC

PCS

PMD/PMA

KSZ8873MLL/FLL/RLL

DS00002348A-page 38  2017 Microchip Technology Inc.

4.0 REGISTER DESCRIPTIONS

4.1 MII Management (MIIM) Registers

The MIIM interface is used to access the MII PHY registers defined in this section. The SPI, I2C, and SMI interfaces can

also be used to access some of these registers. The latter three interfaces use a different mapping mechanism than the

MIIM interface.

The “PHYADs” by defaults are assigned “0x1” for PHY1 (port 1) and “0x2” for PHY2 (port 2). Additionally, these “PHY-

ADs” can be programmed to the PHY addresses specified in bits[7:3] of Register 15 (0x0F): Global Control 13.

The “REGAD” supported are 0x0-0x5, 0x1D, and 0x1F.

TABLE 4-1: MIIM REGISTERS FOR KSZ8873MLL/FLL/RLL

PHYAD = 0x1, REGAD = 0x0 PHY1 Basic Control Register

PHYAD = 0x1, REGAD = 0x1 PHY1 Basic Status Register

PHYAD = 0x1, REGAD = 0x2 PHY1 Physical Identifier I

PHYAD = 0x1, REGAD = 0x3 PHY1 Physical Identifier II

PHYAD = 0x1, REGAD = 0x4 PHY1 Auto-Negotiation Advertisement Register

PHYAD = 0x1, REGAD = 0x5 PHY1 Auto-Negotiation Link Partner Ability Register

PHYAD = 0x1, 0x6 – 0x1C PHY1 Not supported

PHYAD = 0x1, 0x1D PHY1 Not supported

PHYAD = 0x1, 0x1E PHY1 Not supported

PHYAD = 0x1, 0x1F PHY1 Special Control/Status

PHYAD = 0x2, REGAD = 0x0 PHY2 Basic Control Register

PHYAD = 0x2, REGAD = 0x1 PHY2 Basic Status Register

PHYAD = 0x2, REGAD = 0x2 PHY2 Physical Identifier I

PHYAD = 0x2, REGAD = 0x3 PHY2 Physical Identifier II

PHYAD = 0x2, REGAD = 0x4 PHY2 Auto-Negotiation Advertisement Register

PHYAD = 0x2, REGAD = 0x5 PHY2 Auto-Negotiation Link Partner Ability Register

PHYAD = 0x2, 0x6 – 0x1C PHY2 Not supported

PHYAD = 0x2, 0x1D PHY2 LinkMD Control/Status

PHYAD = 0x2, 0x1E PHY2 Not supported

PHYAD = 0x2, 0x1F PHY2 Special Control/Status

 2017 Microchip Technology Inc. DS00002348A-page 39

KSZ8873MLL/FLL/RLL

4.2 Register Descriptions

TABLE 4-2: REGISTER DESCRIPTIONS

Bit Name R/W Description Default Reference

PHY1 Register 0 (PHYAD = 0x1, REGAD = 0x0): MII Basic Control

PHY2 Register 0 (PHYAD = 0x2, REGAD = 0x0): MII Basic Control

15 Soft Reset RO Not Supported 0 —

14 Loopback R/W

1 = Perform loopback, as indicated:

Port 1 Loopback (reg. 29, bit 0 = ‘1’)

Start: RXP2/RXM2 (port 2)

Loopback: PMD/PMA of port 1’s PHY

End: TXP2/TXM2 (port 2)

Port 2 Loopback (reg. 45, bit 0 = ‘1’)

Start: RXP1/RXM1 (port 1)

Loopback: PMD/PMA of port 2’s PHY

End: TXP1/TXM1 (port 1)

0 = Normal operation

0Reg. 29, bit 0

Reg. 45, bit 0

13 Force 100 R/W 1 = 100 Mbps

0 = 10 Mbps 0Reg. 28, bit 6

Reg. 44, bit 6

12 AN Enable R/W 1 = Auto-negotiation enabled

0 = Auto-negotiation disabled 1Reg. 28, bit 7

Reg. 44, bit 7

11 Power Down R/W 1 = Power down

0 = Normal operation 0Reg. 29, bit 3

Reg. 45, bit 3

10 Isolate RO Not Supported 0 —

9Restart ANR/W

1 = Restart auto-negotiation

0 = Normal operation 0Reg. 29, bit 5

Reg. 45, bit 5

8Force Full-

Duplex R/W 1 = Full-duplex

0 = Half-duplex 0Reg. 28, bit 5

Reg. 44, bit 5

7 Collision Test RO Not Supported 0 —

6 Reserved RO — 0 —

5 Hp_mdix R/W 1 = HP Auto MDI/MDI-X mode

0 = Microchip Auto MDI/MDI-X mode 1Reg. 31, bit 7

Reg. 47, bit 7

4Force MDIR/W

1 = Force MDI (transmit on RXP/RXM pins)

0 = Normal operation (transmit on TXP/TXM

pins)

0Reg. 29, bit 1

Reg. 45, bit 1

3Disable

MDIX R/W 1 = Disable auto MDI-X

0 = Enable auto MDI-X 0Reg. 29, bit 2

Reg. 45, bit 2

2Disable Far-

End Fault R/W 1 = Disable far-end fault detection

0 = Normal operation 0 Reg. 29, bit 4

1Disable

Transmit R/W 1 = Disable transmit

0 = Normal operation 0Reg. 29, bit 6

Reg. 45, bit 6

0 Disable LED R/W 1 = Disable LED

0 = Normal operation 0Reg. 29, bit 7

Reg. 45, bit 7

PHY1 Register 1 (PHYAD = 0x1, REGAD = 0x1): MII Basic Status

PHY2 Register 1 (PHYAD = 0x2, REGAD = 0x1): MII Basic Status

15 T4 Capable RO 0 = Not 100BASE-T4 capable 0 —

14 100 Full

Capable RO 1 = 100BASE-TX full-duplex capable

0 = Not capable of 100BASE-TX full-duplex 1 Always 1

13 100 Half

Capable RO 1 = 100BASE-TX half-duplex capable

0 = Not 100BASE-TX half-duplex capable 1 Always 1

12 10 Full

Capable RO 1 = 10BASE-T full-duplex capable

0 = Not 10BASE-T full-duplex capable 1 Always 1

KSZ8873MLL/FLL/RLL

DS00002348A-page 40  2017 Microchip Technology Inc.

11 10 Half

Capable RO 1 = 10BASE-T half-duplex capable

0 = Not 10BASE-T half-duplex capable 1 Always 1

10-7 Reserved RO — 0000 —

6Preamble

Suppressed RO Not Supported 0 —

5 AN Complete RO 1 = Auto-negotiation complete

0 = Auto-negotiation not completed 0Reg. 30, bit 6

Reg. 46, bit 6

4Far-End

Fault RO 1 = Far-end fault detected

0 = No far-end fault detected 0 Reg. 31, bit 0

3 AN Capable RO 1 = Auto-negotiation capable

0 = Not auto-negotiation capable 1Reg. 28, bit 7

Reg. 44, bit 7

2 Link Status RO 1 = Link is up

0 = Link is down 0Reg. 30, bit 5

Reg. 46, bit 5

1 Jabber Test RO Not Supported 0 —

0Extended

Capable RO 0 = Not extended register capable 0 —

PHY1 Register 2 (PHYAD = 0x1, REGAD = 0x2): PHYID High

PHY2 Register 2 (PHYAD = 0x2, REGAD = 0x2): PHYID High

15-0 PHYID High RO High order PHYID bits 0x0022 —

PHY1 Register 3 (PHYAD = 0x1, REGAD = 0x3): PHYID Low

PHY2 Register 3 (PHYAD = 0x2, REGAD = 0x3): PHYID Low

15-0 PHYID Low RO Low order PHYID bits 0x1430 —

PHY1 Register 4 (PHYAD = 0x1, REGAD = 0x4): Auto-Neg otiation Advertisement Ability

PHY2 Register 4 (PHYAD = 0x2, REGAD = 0x4): Auto-Neg otiation Advertisement Ability

15 Next Page RO Not Supported 0 —

14 Reserved RO — 0 —

13 Remote Fault RO Not Supported 0 —

12-11 Reserved RO — 00 —

10 Pause R/W 1 = Advertise pause ability

0 = Do not advertise pause ability 1Reg. 28, bit 4

Reg. 44, bit 4

9 Reserved R/W — 0 —

8 Adv 100 Full R/W 1 = Advertise 100 full-duplex ability

0 = Do not advertise 100 full-duplex ability 1Reg. 28, bit 3

Reg. 44, bit 3

7 Adv 100 Half R/W 1 = Advertise 100 half-duplex ability

0 = Do not advertise 100 half-duplex ability 1Reg. 28, bit 2

Reg. 44, bit 2

6 Adv 10 Full R/W 1 = Advertise 10 full-duplex ability

0 = Do not advertise 10 full-duplex ability 1Reg. 28, bit 1

Reg. 44, bit 1

5 Adv 10 Half R/W 1 = Advertise 10 half-duplex ability

0 = Do not advertise 10 half-duplex ability 1Reg. 28, bit 0

Reg. 44, bit 0

4-0 Selector

Field RO 802.3 00001 —

PHY1 Register 5 (PHYAD = 0x1, REGAD = 0x5): Auto-Negotiation Link Partner Ability

PHY2 Register 5 (PHYAD = 0x2, REGAD = 0x5): Auto-Negotiation Link Partner Ability

15 Next Page RO Not Supported 0 —

14 LP ACK RO Not Supported 0 —

13 Remote Fault RO Not Supported 0 —

12-11 Reserved RO — 00 —

TABLE 4-2: REGISTER DESCRIPTIONS (CONTINUED)

Bit Name R/W Description Default Reference

 2017 Microchip Technology Inc. DS00002348A-page 41

KSZ8873MLL/FLL/RLL

10 Pause RO Link partner pause capability 0 Reg. 30, bit 4

Reg. 46, bit 4

9 Reserved RO — 0 —

8 Adv 100 Full RO Link partner 100 full-duplex capability 0 Reg. 30, bit 3

Reg. 46, bit 3

7 Adv 100 Half RO Link partner 100 half-duplex capability 0 Reg. 30, bit 2

Reg. 46, bit 2

6 Adv 10 Full RO Link partner 10 full-duplex capability 0 Reg. 30, bit 1

Reg. 46, bit 1

5 Adv 10 Half RO Link partner 10 half-duplex capability 0 Reg. 30, bit 0

Reg. 46, bit 0

4-0 Reserved RO — 00000 —

PHY1 Register 29 (PHYAD = 0x1, REGAD = 0x1D): Not support

PHY2 Register 29 (PHYAD = 0x2, REGAD = 0x1D): LinkMD Control/Status

15 Vct_enable R/W

(SC)

1 = Enable cable diagnostic. After VCT test

has completed, this bit will be self-cleared.

0 = Indicate cable diagnostic test (if enabled)

has completed and the status information is

valid for read.

0 Reg. 42, bit 4

14-13 Vct_result RO

00 = Normal condition

01 = Open condition detected in cable

10 = Short condition detected in cable

11 = Cable diagnostic test has failed

00 Reg 42, bit[6:5]

12 Vct 10M

Short RO 1 = Less than 10 meter short 0 Reg. 42, bit 7

11-9 Reserved RO Reserved 000 —

8-0 Vct_-

fault_count RO Distance to the fault.

It’s approximately 0.4m*vct_fault_count[8:0] {0, (0x00)}

{(Reg. 42, bit 0),

(Reg. 43,

bit[7:0])}

PHY1 Register 31 (PHYAD = 0x1, REGAD = 0x1F): PHY Special Control/Status

PHY2 Register 31 (PHYAD = 0x2, REGAD = 0x1F): PHY Special Control/Status

15-6 Reserved RO Reserved {(0x00),00} —

5Polrvs RO

1 = polarity is reversed

0 = polarity is not reversed 0

Reg. 31, bit 5

Reg. 47, bit 5

Note: This bit is

only valid for

10BT

4 MDI-X status RO 1 = MDI

0 = MDI-X 0Reg. 30, bit 7

Reg. 46, bit 7

3 Force_lnk R/W 1 = Force link pass

0 = Normal Operation 0Reg. 26, bit 3

Reg. 42, bit 3

2 Pwrsave R/W 0 = Enable power saving

1 = Disable power saving 1Reg. 26, bit 2

Reg. 42, bit 2

TABLE 4-2: REGISTER DESCRIPTIONS (CONTINUED)

Bit Name R/W Description Default Reference

KSZ8873MLL/FLL/RLL

DS00002348A-page 42  2017 Microchip Technology Inc.

4.3 Memory Map (8-Bit Registers)

1Remote

Loopback R/W

1 = Perform Remote loopback, as follows:

Port 1 (reg. 26, bit 1 = ‘1’)

Start: RXP1/RXM1 (port 1)

Loopback: PMD/PMA of port 1’s PHY

End: TXP1/TXM1 (port 1)

Port 2 (reg. 42, bit 1 = ‘1’)

Start: RXP2/RXM2 (port 2)

Loopback: PMD/PMA of port 2’s PHY

End: TXP2/TXM2 (port 2)

0 = Normal Operation

0Reg. 26, bit 1

Reg. 42, bit 1

0 Reserved R/W Reserved

Do not change the default value. 0—

TABLE 4-3: GLOBAL REGISTERS

0-1 0x00-0x01 Chip ID Register

2-15 0x02-0x0F Global Control Register

TABLE 4-4: PORT REGISTERS

16-29 0x10-0x1D Port 1 Control Registers, including MII PHY Registers

30-31 0x1E-0x1F Port 1 Status Registers, including MII PHY Registers

32-45 0x20-0x2D Port 2 Control Registers, including MII PHY Registers

46-47 0x2E-0x2F Port 2 Status Registers, including MII PHY Registers

48-57 0x30-0x39 Port 3 Control Registers

58-62 0x3A-0x3E Reserved

63 0x3F Port 3 Status Register

64-95 0x40-0x5F Reserved

TABLE 4-5: ADVANCED CONTROL REGISTERS

96-111 0x60-0x6F TOS Priority Control Registers

112-117 0x70-0x75 Switch Engine’s MAC Address Registers

118-120 0x76-0x78 User Defined Registers

121-122 0x79-0x7A Indirect Access Control Registers

123-131 0x7B-0x83 Indirect Data Registers

142-153 0x8E-0x99 Station Address

154-165 0x9A-0xA5 Egress Data Rate Limit

166 0xA6 Device Mode Indicator

167-170 0xA7-0xAA High Priority Packet Buffer Reserved

171-174 0xAB-0xAE PM Usage Flow Control Select Mode

175-186 0xAF-0xBA TXQ Split

187-188 0xBB-0xBC Link Change Interrupt Register

189 0xBD Force Pause Off Iteration Limit Enable

TABLE 4-2: REGISTER DESCRIPTIONS (CONTINUED)

Bit Name R/W Description Default Reference

 2017 Microchip Technology Inc. DS00002348A-page 43

KSZ8873MLL/FLL/RLL

4.4 Register Descriptions

192 0xC0 Fiber Signal Threshold

194 0xC2 Insert SRC PVID

195 0xC3 Power Management and LED Mode

196 0xC4 Sleep Mode

198 0xC6 Forward Invalid VID Frame and Host Mode

TABLE 4-6: GLOBAL REGISTERS (0-15)

Bit Name R/W Description Default

7-0 Family ID RO Chip family 0x88

7-4 Chip ID RO 0x3 is assigned to M series. (73M) 0x3

3-1 Revision ID RO Revision ID —

0 Start Switch R/W 1 = start the switch (default)

0 = stop the switch 1

7New Back-Off

Enable R/W

New back-off algorithm designed for UNH

1 = Enable

0 = Disable

6 Reserved RO Reserved 0

5Flush Dynamic MAC

Table R/W

1 = enable flush dynamic MAC table for spanning tree

application

0 = disable

4Flush Static MAC

Table R/W

1 = enable flush static MAC table for spanning tree

application

0 = disable

3Pass Flow Control

Packet R/W 1 = switch will pass 802.1x flow control packets

0 = switch will drop 802.1x flow control packets 0

2 Reserved R/W Reserved

Do not change the default value. 0

1 Reserved R/W Reserved

Do not change the default value. 0

0 Reserved RO Reserved 0

7 Pass All Frames R/W

1 = switch all packets including bad ones. Used solely

for debugging purposes. Works in conjunction with

sniffer mode only.

6Port 3 Tail Tag Mode

Enable R/W 1 = Enable port 3 tail tag mode.

0 = Disable. 0

IEEE 802.3x

Transmit Direction

Flow Control Enable

R/W

1 = will enable transmit direction flow control feature.

0 = will not enable transmit direction flow control fea-

ture. Switch will not generate any flow control

(PAUSE) frame.

TABLE 4-5: ADVANCED CONTROL REGISTERS (CONTINUED)

KSZ8873MLL/FLL/RLL

DS00002348A-page 44  2017 Microchip Technology Inc.

IEEE 802.3x

Receive Direction

Flow Control Enable

R/W

1 = will enable receive direction flow control feature.

0 = will not enable receive direction flow control fea-

ture. Switch will not react to any flow control (PAUSE)

frame it receives.

3Frame Length Field

Check R/W

1 = will check frame length field in the IEEE packets. If

the actual length does not match, the packet will be

dropped (for Length/Type field < 1500).

0 = will not check

2 Aging Enable R/W 1 = enable age function in the chip

0 = disable age function in the chip 1

1 Fast Age Enable R/W 1 = turn on fast age (800 µs) 0

0Aggressive Back-Off

Enable R/W

1 = enable more aggressive back off algorithm in half-

duplex mode to enhance performance. This is not an

IEEE standard.

7Unicast Port-VLAN

Mismatch Discard R/W

This feature is used with port-VLAN (described in reg.

17, reg. 33, etc.)

1 = all packets cannot cross VLAN boundary

0 = unicast packets (excluding unkown/multicast/

broadcast) can cross VLAN boundary

Note: Port mirroring is not supported if this bit is set to

“0”.

6Multicast Storm

Protection Disable R/W

1 = Broadcast Storm Protection does not include

multicast packets. Only DA = FF-FF-FF-FF-FF-FF

packets will be regulated.

0 = Broadcast Storm Protection includes DA = FF-FF-

FF-FF-FF-FF and DA[40] = 1 packets.

5 Back Pressure Mode R/W 1 = carrier sense based back pressure is selected

0 = collision based back pressure is selected 1

Flow Control and

Back Pressure Fair

Mode

R/W

1 = Fair mode is selected. In this mode, if a flow con-

trol port and a non-flow control port talk to the same

destination port, packets from the non-flow control

port may be dropped. This is to prevent the flow con-

trol port from being flow controlled for an extended

period of time.

0 = In this mode, if a flow control port and a non-flow

control port talk to the same destination port, the flow

control port will be flow controlled. This may not be

“fair” to the flow control port.

3No Excessive

Collision Drop R/W

1 = the switch will not drop packets when 16 or more

collisions occur.

0 = the switch will drop packets when 16 or more colli-

sions occur.

2Huge Packet

Support R/W

1 = will accept packet sizes up to 1916 bytes (inclu-

sive). This bit setting will override setting from bit 1 of

this register.

0 = the max packet size will be determined by bit 1 of

this register.

Legal Maximum

Packet Size Check

Enable

R/W

0 = will accept packet sizes up to 1536 bytes (inclu-

sive).

1 = 1522 bytes for tagged packets, 1518 bytes for

untagged packets. Any packets larger than the speci-

fied value will be dropped.

TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 45

KSZ8873MLL/FLL/RLL

0 Reserved R/W Reserved

Do not change the default value. 0

7802.1Q VLAN

Enable R/W

1 = 802.1Q VLAN mode is turned on. VLAN table

needs to set up before the operation.

0 = 802.1Q VLAN is disabled.

IGMP Snoop Enable

on Switch MII

Interface

R/w

1 = IGMP snoop is enabled. All IGMP packets will be

forwarded to the Switch MII port.

0 = IGMP snoop is disabled.

5 Reserved RO Reserved

Do not change the default values. 0

4 Reserved RO Reserved

Do not change the default values. 0

3Weighted Fair

Queue Enable R/W

0 = Priority method set by the registers 175-186 bit [7]

= 0 for port 1, port 2, and port 3.

1 = Weighted Fair Queuing enabled. When all four

queues have packets waiting to transmit, the band-

width allocation is q3:q2:q1:q0 = 8:4:2:1.

If any queues are empty, the highest non-empty

queue gets one more weighting. For example, if q2 is

empty, q3:q2:q1:q0 becomes (8+1):0:2:1.

2 Reserved RO Reserved

Do not change the default values. 0

1 Reserved RO Reserved

Do not change the default values. 0

0 Sniff Mode Select R/W

1 = will do RX AND TX sniff (both source port and

destination port need to match)

0 = will do RX OR TX sniff (either source port or desti-

nation port needs to match). This is the mode used to

implement RX only sniff.

7 Reserved RO Reserved

Do not change the default values. 0

6Port 3 Duplex Mode

Selection R/W 1 = Enable Port 3 MII to half-duplex mode.

0 = Enable Port 3 MII to full-duplex mode.

Pin P1LED0

strap option.

Pull-up(1): Half -

duplex mode

Pull-down(0):

Full-duplex

mode (default)

Note: P1LED0

has internal pull-

down.

TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 46  2017 Microchip Technology Inc.

5Port 3 Flow Control

Enable R/W

1 = Enable full-duplex flow control on Switch port 3

MII interface.

0 = Disable full-duplex flow control on Switch port 3

MII interface.

Pin P1LED1

strap option.

Pull- up(1):

Enable flow

control

Pull-down(0):

Disable flow

control

Note: P1LED1

has internal pull-

up.

4Port 3 Speed

Selection R/W

1 = the Port 3 MII switch interface is in 10 Mbps mode

0 = the Port 3 MII switch interface is in 100 Mbps

mode

Pin P3SPD

strap option.

Pull-up(1):

Enable 10 Mbps

Pull-down(0):

Enable

100 Mbps

(default)

Note: P3SPD

has internal pull-

down.

3Null VID

Replacement R/W 1 = will replace NULL VID with port VID (12 bits)

0 = no replacement for NULL VID 0

2-0

Broadcast Storm

Protection Rate

Bit [10:8]

R/W

This register along with the next register determines

how many “64 byte blocks” of packet data are allowed

on an input port in a preset period. The period is

67 ms for 100BT or 500 ms for 10BT. The default is

1%.

000

7-0

Broadcast Storm

Protection Rate

Bit [7:0]

R/W

This register along with the previous register deter-

mines how many “64 byte blocks” of packet data are

allowed on an input port in a preset period. The period

is 67 ms for 100BT or 500 ms for 10BT. The default is

1%.

Note: 100BT Rate: 148,800 frames/sec * 67 ms/inter-

val * 1% = 99 frames/interval (approx.) = 0x63

0x63

7-0 Factory Testing RO Reserved

Do not change the default values. 0x00

7-0 Factory Testing RO Reserved

Do not change the default values. 0x24

7-0 Factory Testing RO Reserved

Do not change the default values. 0x35

TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 47

KSZ8873MLL/FLL/RLL

7-6 CPU Interface Clock

Selection R/W

00 = 31.25 MHz supports SPI speed below 6 MHz

01 = 62.5 MHz supports SPI speed between 6 MHz to

12.5 MHz

10 = 125 MHz supports SPI speed above 12.5 MHz

Note: Lower clock speed will save more power; It is

better set to 31.25 MHz if SPI doesn’t request a high

speed.

5-4 Reserved RO N/A Don’t Change 00

3-2 Reserved RO N/A Don’t Change 10

1 Reserved RO N/A Don’t Change 0

0 Reserved RO N/A Don’t Change 0

7-6 Tag_0x3 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x3.

5-4 Tag_0x2 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x2.

3-2 Tag_0x1 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x1.

1-0 Tag_0x0 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x0.

7-6 Tag_0x7 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x7.

5-4 Tag_0x6 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x6.

3-2 Tag_0x5 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x5.

1-0 Tag_0x4 R/W

IEEE 802.1p mapping. The value in this field is used

as the frame’s priority when its IEEE 802.1p tag has a

value of 0x4.

7Unknown Packet

Default Port Enable R/W

Send packets with unknown destination MAC

addresses to specified port(s) in bits [2:0] of this regis-

ter.

0 = disable

1 = enable

6Drive Strength of I/O

Pad R/W 1: 16 mA

0: 8 mA 1

5 Reserved RO Reserved

Do not change the default values. 0

4 Reserved RO Reserved

Do not change the default values. 0

TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 48  2017 Microchip Technology Inc.

3 Reserved RO Reserved

Do not change the default values. 0

2-0 Unknown Packet

Default Port R/W

Specify which port(s) to send packets with unknown

destination MAC addresses. This feature is enabled

by bit [7] of this register.

Bit 2 stands for port 3.

Bit 1 stands for port 2.

Bit 0 stands for port 1.

A ‘1’ includes a port.

A ‘0’ excludes a port.

111

7-3 PHY Address R/W

00000: N/A

00001: Port 1 PHY address is 0x1

00010: Port 1 PHY address is 0x2

…

11101: Port 1 PHY address is 0x29

11110: N/A

11111: N/A

Note:

Port 2 PHY address = (Port 1 PHY address) + 1

00001

2-0 Reserved RO Reserved

Do not change the default values. 000

TABLE 4-6: GLOBAL REGISTERS (0-15) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 49

KSZ8873MLL/FLL/RLL

The following registers are used to enable features that are assigned on a per port basis. The register bit assignments

are the same for all ports, but the address for each port is different, as indicated.

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95)

Bit Name R/W Description Default

7Broadcast Storm

Protection Enable R/W

1 = enable broadcast storm protection for ingress

packets on port

0 = disable broadcast storm protection

6DiffServ Priority

Classification Enable R/W

1 = enable DiffServ priority classification for ingress

packets (IPv4) on port

0 = disable DiffServ function

5802.1p Priority Clas-

sification Enable R/W

1 = enable 802.1p priority classification for ingress

packets on port

0 = disable 802.1p

4-3 Port-based Priority

Classification R/W

00 = ingress packets on port will be

classified as priority 0 queue if “Diffserv” or “802.1p”

classification is not enabled or fails to classify.

01 = ingress packets on port will be

classified as priority 1 queue if “Diffserv” or “802.1p”

classification is not enabled or fails to classify.

10 = ingress packets on port will be

classified as priority 2 queue if “Diffserv” or “802.1p”

classification is not enabled or fails to classify.

11 = ingress packets on port will be

classified as priority 3 queue if “Diffserv” or “802.1p”

classification is not enabled or fails to classify.

Note: “DiffServ,” “802.1p,” and port priority can be

enabled at the same time. The OR’ed result of 802.1p

and DSCP overwrites the port priority.

2 Tag Insertion R/W

1 = when packets are output on the port, the switch

will add 802.1p/q tags to packets without 802.1p/q

tags when received. The switch will not add tags to

packets already tagged. The tag inserted is the

ingress port’s “port VID”.

0 = disable tag insertion

Note: For the tag insertion available, the register 194

bits [5:0] have to be set first.

1 Tag Removal R/W

1 = when packets are output on the port, the switch

will remove 802.1p/q tags from packets with 802.1p/q

tags when received. The switch will not modify pack-

ets received without tags.

0 = disable tag removal

0 TXQ Split Enable R/W

1 = split TXQ to 4 queue configuration. It cannot be

enable at the same time with split 2 queue at register

18, 34, 50 bit 7.

0 = no split, treated as 1 queue configuration

7 Sniffer Port R/W

1 = Port is designated as sniffer port and will transmit

packets that are monitored.

0 = Port is a normal port

KSZ8873MLL/FLL/RLL

DS00002348A-page 50  2017 Microchip Technology Inc.

6 Receive Sniff R/W

1 = All packets received on the port will be marked as

“monitored packets” and forwarded to the designated

“sniffer port”

0 = no receive monitoring

5 Transmit Sniff R/W

1 = All packets transmitted on the port will be marked

as “monitored packets” and forwarded to the desig-

nated “sniffer port”

0 = no transmit monitoring

4 Double Tag R/W

1 = All packets will be tagged with port default tag of

ingress port regardless of the original packets are

tagged or not

0 = do not double tagged on all packets

3 User Priority Ceiling R/W

1 = if the packet’s “user priority field” is greater than

the “user priority field” in the port default tag register,

replace the packet’s “user priority field” with the “user

priority field” in the port default tag register.

0 = do not compare and replace the packet’s ‘user pri-

ority field”

2-0 Port VLAN

Membership R/W

Define the port’s egress port VLAN membership. The

port can only communicate within the membership. Bit

2 stands for port 3, bit 1 stands for port 2, bit 0 stands

for port 1.

An ‘1’ includes a port in the membership.

An ‘0’ excludes a port from membership.

111

7Enable 2 Queue Split

of Tx Queue R/W

1 = Enable

It cannot be enable at the same time with split 4

queue at register 16, 32, and 48 bit 0.

0 = Disable

6Ingress VLAN

Filtering R/W

1 = the switch will discard packets whose VID port

membership in VLAN table bits [18:16] does not

include the ingress port.

0 = no ingress VLAN filtering.

5Discard non-PVID

Packets R/W

1 = the switch will discard packets whose VID does

not match ingress port default VID.

0 = no packets will be discarded

4 Force Flow Control R/W

1 = will always enable full-duplex flow control on the

port, regardless of AN result.

0 = full-duplex flow control is enabled based on AN

result.

Pin value during

reset:

For port 1,

P1FFC pin

For port 2,

SMRXD30 pin

For port 3, this

bit has no

meaning. Flow

control is set by

Reg. 6 bit 5.

3Back Pressure

Enable R/W 1 = enable port’s half-duplex back pressure

0 = disable port’s half-duplex back pressure 0

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 51

KSZ8873MLL/FLL/RLL

2 Transmit Enable R/W

1 = enable packet transmission on the port

0 = disable packet transmission on the port

Note: This bit is used for spanning tree support.

1 Receive Enable R/W

1 = enable packet reception on the port

0 = disable packet reception on the port

Note: This bit is used for spanning tree support.

0 Learning Disable R/W

1 = disable switch address learning capability

0 = enable switch address learning

Note: This bit is used for spanning tree support.

7-0 Default Tag [15:8] R/W

Port’s default tag, containing

7-5 = User priority bits

4 = CFI bit

3-0 = VID[11:8]

0x00

7-0 Default Tag [7:0] R/W Port’s default tag, containing 7-0: VID[7:0] 0x01

Note: Registers 19 and 20 (and those corresponding to other ports) serve two purposes:

Associated with the ingress untagged packets, and used for egress tagging.

Default VID for the ingress untagged or null-VID-tagged packets, and used for address lookup.

7Port 3 MII Mode

Selection R/W

1 = Port 3 MII MAC mode

0 = Port 3 MII PHY mode

Note: Bit 7 is reserved in the port 1 and port 2 of the

port register control 5. But its recommended to set the

because this bit 7 of the register 21 is for port 1 MII of

the MML part. In the MLL/FLL/RLL parts, setting this

bit will disable the unused internal 25 MHz clock for

the unused port 1 MII PHY mode circuits.

Inversion of

power strapped

value

of SMRXDV3

Self-Address Filter-

ing Enable MACA1

(not for 0x35)

R/W 1 = enable port 1 self-address filtering MACA1

0 = disable 0

Self-Address Filter-

ing Enable MACA2

(not for 0x35)

R/W 1 = enable port 2 self-address filtering MACA2

0 = disable 0

4Drop Ingress Tagged

Frame R/W 1 = Enable

0 = Disable 0

3-2 Limit Mode R/W

Ingress Limit Mode

These bits determine what kinds of frames are limited

and counted against ingress rate limiting.

00 = limit and count all frames

01 = limit and count Broadcast, Multicast, and flooded

unicast frames

10 = limit and count Broadcast and Multicast frames

only

11 = limit and count Broadcast frames only

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 52  2017 Microchip Technology Inc.

1 Count IFG R/W

Count IFG bytes

1 = each frame’s minimum inter frame gap

(IFG) bytes (12 per frame) are included in Ingress and

Egress rate limiting calculations.

0 = IFG bytes are not counted.

0 Count Pre R/W

Count Preamble bytes

1 = each frame’s preamble bytes (8 per frame) are

included in Ingress and Egress rate limiting calcula-

tions.

0 = preamble bytes are not counted.

7RMII REFCLK

INVERT R/W

1: Port 3 inverted refclk selected

0: Port 3 original refclk selected

Note: Bit 7 is available on port 3 in the RLL device.

Other ports and devices will be reserved for this bit.

Note: Not

applied to

Reg.38

(Port 2)

6-0 Q0 Ingress Data

Rate Limit R/W

Ingress data rate limit for priority 0 frames

Ingress traffic from this priority queue is shaped

according to the ingress Data Rate Selected Table.

7 Reserved R/W Reserved

Do not change the default values. 0

6-0 Q1 Ingress Data

Rate Limit R/W

Ingress data rate limit for priority 1 frames

Ingress traffic from this priority queue is shaped

according to the ingress Data Rate Selected Table.

7 Reserved R/W Reserved

Do not change the default values. 0

6-0 Q2 Ingress Data

Rate Limit R/W

Ingress data rate limit for priority 2 frames

Ingress traffic from this priority queue is shaped

according to ingress Data Rate Selection Table.

7 Reserved RO Reserved

Do not change the default values. 0

6-0 Q3 Ingress Data

Rate Limit R/W

Ingress data rate limit for priority 3 frames

Ingress traffic from this priority queue is shaped

according to ingress Data Rate Selection Table.

Note: Most of the contents in registers 26-31 and registers 42-47 for ports 1 and 2, respectively, can also be

accessed with the MIIM PHY registers.

7 Vct 10M Short RO 1 = Less than 10 meter short 0

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 53

KSZ8873MLL/FLL/RLL

6-5 Vct_result RO

00 = Normal condition

01 = Open condition detected in cable

10 = Short condition detected in cable

11 = Cable diagnostic test has failed

4 Vct_en R/W

(SC)

1 = Enable cable diagnostic test. After VCT test has

completed, this bit will be self-cleared.

0 = Indicate cable diagnostic test (if enabled) has

completed and the status information is valid for read.

3 Force_lnk R/W 1 = Force link pass

0 = Normal Operation 0

2 Reserved RO Reserved

Do not change the default value. 0

1 Remote Loopback R/W

1 = Perform Remote loopback, as follows:

Port 1 (reg. 26, bit 1 = ‘1’)

Start: RXP1/RXM1 (port 1)

Loopback: PMD/PMA of port 1’s PHY

End: TXP1/TXM1 (port 1)

Port 2 (reg. 42, bit 1 = ‘1’)

Start: RXP2/RXM2 (port 2)

Loopback: PMD/PMA of port 2’s PHY

End: TXP2/TXM2 (port 2)

0 = Normal Operation

0 Vct_fault_count[8] RO

Bit[8] of VCT fault count

Distance to the fault.

It’s approximately 0.4m*vct_fault_count[8:0]

7-0 Vct_fault_count[7:0] RO

Bits[7:0] of VCT fault count

Distance to the fault.

It’s approximately 0.4m*Vct_fault_count[8:0]

0x00

7Auto Negotiation

Enable R/W

1 = auto negotiation is on

0 = disable auto negotiation; speed and duplex are

determined by bits 6 and 5 of this register.

For port 1,

P1ANEN pin

value during

reset.

For port 2,

SMRXD33 pin

value during

reset

6 Force Speed R/W 1 = forced 100BT if AN is disabled (bit 7)

0 = forced 10BT if AN is disabled (bit 7)

For port 1,

P1SPD pin

value during

reset.

For port 2,

SMRXD32 pin

value during

reset.

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 54  2017 Microchip Technology Inc.

5 Force Duplex R/W

1 = forced full-duplex if (1) AN is disabled or (2) AN is

enabled, but failed.

0 = forced half-duplex if (1) AN is disabled or (2) AN is

enabled but failed.

Note: This bit or strap pin should be set to ‘0’ for the

correct duplex mode indication of LED and register

status when the link-up is AN to force mode.

For port 1,

P1DPX pin

value during

reset.

For port 2,

SMRXD31 pin

value during

reset.

4Advertise Flow

Control Capability R/W

1 = advertise flow control (pause) capability

0 = suppress flow control (pause) capability from

transmission to link partner

Advertise 100BT

Full-Duplex

Capability

R/W

1 = advertise 100BT full-duplex capability

0 = suppress 100BT full-duplex capability from trans-

mission to link partner

Advertise 100BT

Half-Duplex

Capability

R/W

1 = advertise 100BT half-duplex capability

0 = suppress 100BT half-duplex capability from trans-

mission to link partner

1Advertise 10BT Full-

Duplex Capability R/W

1 = advertise 10BT full-duplex capability

0 = suppress 10BT full-duplex capability from trans-

mission to link partner

0Advertise 10BT Half-

Duplex Capability R/W

1 = advertise 10BT half-duplex capability

0 = suppress 10BT half-duplex capability from trans-

mission to link partner

7 LED Off R/W

1 = turn off all port’s LEDs (LEDx_1, LEDx_0, where

“x” is the port number). These pins will be driven high

if this bit is set to ‘1’.

0 = normal operation

6 Txdis R/W 1 = disable the port’s transmitter

0 = normal operation 0

5Restart AN R/W

1 = restart auto-negotiation

0 = normal operation 0

4Disable Far-End

Fault R/W

1 = disable far-end fault detection and pattern trans-

mission.

0 = enable far-end fault detection and pattern trans-

mission

3 Power Down R/W 1 = power down

0 = normal operation 0

2Disable Auto MDI/

MDI-X R/W 1 = disable auto MDI/MDI-X function

0 = enable auto MDI/MDI-X function 0

1Force MDI R/W

If auto MDI/MDI-X is disabled,

1 = force PHY into MDI mode (transmit on RXP/RXM

pins)

0 = force PHY into MDI-X mode (transmit on TXP/

TXM pins)

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 55

KSZ8873MLL/FLL/RLL

0 Loopback R/W

1 = perform loopback, as indicated:

Port 1 Loopback (reg. 29, bit 0 = ‘1’)

Start: RXP2/RXM2 (port 2)

Loopback: PMD/PMA of port 1’s PHY

End: TXP2/TXM2 (port 2)

Port 2 Loopback (reg. 45, bit 0 = ‘1’)

Start: RXP1/RXM1 (port 1)

Loopback: PMD/PMA of port 2’s PHY

End: TXP1/TXM1 (port 1)

0 = normal operation

7 MDI-X Status RO 1 = MDI

0 = MDI-X 0

6 AN Done RO 1 = auto-negotiation completed

0 = auto-negotiation not completed 0

5 Link Good RO 1 = link good

0 = link not good 0

4Partner Flow Con-

trol Capability RO 1 = link partner flow control (pause) capable

0 = link partner not flow control (pause) capable 0

3Partner 100BT Full-

Duplex Capability RO 1 = link partner 100BT full-duplex capable

0 = link partner not 100BT full-duplex capable 0

2Partner 100BT Half-

Duplex Capability RO 1 = link partner 100BT half-duplex capable

0 = link partner not 100BT half-duplex capable 0

1Partner 10BT Full-

Duplex Capability RO 1 = link partner 10BT full-duplex capable

0 = link partner not 10BT full-duplex capable 0

0Partner 10BT Half-

Duplex Capability RO 1 = link partner 10BT half-duplex capable

0 = link partner not 10BT half-duplex capable 0

7 Hp_mdix R/W 1 = HP Auto MDI/MDI-X mode

0 = Microchip Auto MDI/MDI-X mode

Note: Only ports

1 and 2 are PHY

ports.

This bit is not

applicable to

port 3 (MII).

6 Reserved RO Reserved

Do not change the default value. 0

5Polrvs RO

1 = polarity is reversed

0 = polarity is not reversed

Note: This bit is

not applicable to

port 3 (MII).

This bit is only

valid for 10BT

4Transmit Flow

Control Enable RO 1 = transmit flow control feature is active

0 = transmit flow control feature is inactive 0

3Receive Flow

Control Enable RO 1 = receive flow control feature is active

0 = receive flow control feature is inactive 0

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 56  2017 Microchip Technology Inc.

2 Operation Speed RO 1 = link speed is 100 Mbps

0 = link speed is 10 Mbps 0

1 Operation Duplex RO 1 = link duplex is full

0 = link duplex is half 0

0 Far-End Fault RO 1 = far-end fault status detected

0 = no far-end fault status detected

Note: This bit is

applicable to

port 1 and port 2

for FLL part

only.

4 Software Reset R/W

1 = Software reset

0 = Clear

Note: Software reset will reset all registers to the initial

values of the power-on reset or warm reset (keep the

strap values).

0PCS Reset R/W

1 = PCS reset is used when is doing software reset

for a complete reset

0 = Clear

Note: PCS reset will reset the state machine and

clock domain in PHY’s PCS layer.

TABLE 4-8: DATA RATE LIMIT

Data Rate Limit for

Ingress or Egress 100BT

—1 to 0x63 for 1 Mbps to 99 Mbps Rate 1 to 0x09 for 1 Mbps to 9 Mbps Rate

0 or 0x64 for 100 Mbps Rate 0 or 0x0A for 10 Mbps Rate

64 kbps 0x65

128 kbps 0x66

192 kbps 0x67

256 kbps 0x68

320 kbps 0x69

384 kbps 0x6A

448 kbps 0x6B

512 kbps 0x6C

576 kbps Data 0x6D

640 kbps 0x6E

704 kbps 0x6F

768 kbps 0x70

832 kbps 0x71

896 kbps 0x72

960 kbps 0x73

TABLE 4-7: PORT REGISTERS (REGISTERS 16 - 95) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 57

KSZ8873MLL/FLL/RLL

4.5 Advanced Control Registers (Registers 96-198)

The IPv4/IPv6 TOS Priority Control Registers implement a fully decoded, 128-bit Differentiated Services Code Point

(DSCP) register set that is used to determine priority from the Type of Service (TOS) field in the IP header. The most

significant 6 bits of the TOS field are fully decoded into 64 possibilities, and the singular code that results is compared

against the corresponding bits in the DSCP register to determine the priority.

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198)

Bit Name R/W Description Default

7-6 DSCP[7:6] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x03.

5-4 DSCP[5:4] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x02.

3-2 DSCP[3:2] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x01.

1-0 DSCP[1:0] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x00.

7-6 DSCP[15:14] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x07.

5-4 DSCP[13:12] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x06.

3-2 DSCP[11:10] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x05.

1-0 DSCP[9:8] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x04.

7-6 DSCP[23:22] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0B.

5-4 DSCP[21:20] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0A.

3-2 DSCP[19:18] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x09.

1-0 DSCP[17:16] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x08.

7-6 DSCP[31:30] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0F.

KSZ8873MLL/FLL/RLL

DS00002348A-page 58  2017 Microchip Technology Inc.

5-4 DSCP[29:28] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0E.

3-2 DSCP[27:26] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0D.

1-0 DSCP[25:24] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x0C.

7-6 DSCP[39:38] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x13.

5-4 DSCP[37:36] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x12.

3-2 DSCP[35:34] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x11.

1-0 DSCP[33:32] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x10.

7-6 DSCP[47:46] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x17.

5-4 DSCP[45:44] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x16.

3-2 DSCP[43:42] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x15.

1-0 DSCP[41:40] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x14.

7-6 DSCP[55:54] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1B.

5-4 DSCP[53:52] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1A.

3-2 DSCP[51:50] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x19.

1-0 DSCP[49:48] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x18.

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 59

KSZ8873MLL/FLL/RLL

7-6 DSCP[63:62] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1F.

5-4 DSCP[61:60] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1E.

3-2 DSCP[59:58] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1D.

1-0 DSCP[57:56] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x1C.

7-6 DSCP[71:70] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x23.

5-4 DSCP[69:68] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x22.

3-2 DSCP[67:66] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x21.

1-0 DSCP[65:64] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x20.

7-6 DSCP[79:78] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x27.

5-4 DSCP[77:76] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x26.

3-2 DSCP[75:74] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x25.

1-0 DSCP[73:72] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x24.

7-6 DSCP[87:86] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2B.

5-4 DSCP[85:84] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2A.

3-2 DSCP[83:82] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x29.

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 60  2017 Microchip Technology Inc.

1-0 DSCP[81:80] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x28.

7-6 DSCP[95:94] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2F.

5-4 DSCP[93:92] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2E.

3-2 DSCP[91:90] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2D.

1-0 DSCP[89:88] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x2C.

7-6 DSCP[103:102] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x33.

5-4 DSCP[101:100] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x32.

3-2 DSCP[99:98] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x31.

1-0 DSCP[97:96] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x30.

7-6 DSCP[111:110] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x37.

5-4 DSCP[109:108] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x36.

3-2 DSCP[107:106] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x35.

1-0 DSCP[105:104] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x34.

7-6 DSCP[119:118] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3B.

5-4 DSCP[117:116] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3A.

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 61

KSZ8873MLL/FLL/RLL

3-2 DSCP[115:114] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x39.

1-0 DSCP[113:112] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x38.

7-6 DSCP[127:126] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3F.

5-4 DSCP[125:124] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3E.

3-2 DSCP[123:122] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3D.

1-0 DSCP[121:120] R/W

The value in this field is used as the frame’s priority

when bits [7:2] of the frame’s IP TOS/DiffServ/Traffic

Class value is 0x3C.

Registers 112 to 117 contain the switch engine’s MAC address. This 48-bit address is used as the Source Address

for the MAC’s full duplex flow control (PAUSE) frame.

7-0 MACA[47:40] R/W — 0x00

7-0 MACA[39:32] R/W — 0x10

7-0 MACA[31:24] R/W — 0xA1

7-0 MACA[23:16] R/W — 0xFF

7-0 MACA[15:8] R/W — 0xFF

7-0 MACA[7:0] R/W — 0xFF

Registers 118 to 120 are User Defined Registers (UDRs). These are general purpose read/write registers that can be

used to pass user defined control and status information between the KSZ8873 and the external processor.

7-0 UDR1 R/W — 0x00

7-0 UDR2 R/W — 0x00

7-0 UDR3 R/W — 0x00

Registers 121 to 131 provide read and write access to the static MAC address table, VLAN table, dynamic MAC

address table, and MIB counters.

7-5 Reserved R/W Reserved

Do not change the default values. 000

4Read High/Write

Low R/W 1 = read cycle

0 = write cycle 0

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 62  2017 Microchip Technology Inc.

3-2 Table Select R/W

00 = static MAC address table selected

01 = VLAN table selected

10 = dynamic MAC address table selected

11 = MIB counter selected

1-0 Indirect Address

High R/W Bits [9:8] of indirect address 00

7-0 Indirect Address Low R/W

Bits [7:0] of indirect address. Note: A write to register

122 triggers the read/write command. Read or write

access is determined by register 121 bit 4.

0000_0000

7 CPU Read Status RO

This bit is applicable only for dynamic MAC address

table and MIB counter reads.

1 = read is still in progress

0 = read has completed

6-3 Reserved RO Reserved 0000

2-0 Indirect Data [66:64] RO Bits [66:64] of indirect data 000

7-0 Indirect Data [63:56] R/W Bits [63:56] of indirect data 0000_0000

7-0 Indirect Data [55:48] R/W Bits [55:48] of indirect data 0000_0000

7-0 Indirect Data [47:40] R/W Bits [47:40] of indirect data 0000_0000

7-0 Indirect Data [39:32] R/W Bits [39:32] of indirect data 0000_0000

7-0 Indirect Data [31:24] R/W Bits [31:24] of indirect data 0000_0000

7-0 Indirect Data [23:16] R/W Bits [23:16] of indirect data 0000_0000

7-0 Indirect Data [15:8] R/W Bits [15:8] of indirect data 0000_0000

7-0 Indirect Data [7:0] R/W Bits [7:0] of indirect data 0000_0000

47-0 Station Address R/W

48-bit Station address MACA1 and MACA2.

Note: The station address is used for self MAC

address filtering, see the port register control 5 bits

[6,5] for detail.

48’h0

Note: the MSB

bits[47-40] of

the MAC is the

153. The LSB

bits[7-0] of MAC

is the register

142 and 148.

7Egress Rate Limit

Flow Control Enable R/W 1 = enable egress rate limit flow control.

0 = disable 0

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 63

KSZ8873MLL/FLL/RLL

6-0 Q0 Egress Data

Rate Limit R/W

Egress data rate limit for priority 0 frames

Egress traffic from this priority queue is shaped

according to Ta b l e 4 - 8 .

7 Reserved R/W Reserved

Do not change the default values. 0

6-0 Q1 Egress Data

Rate Limit R/W

Egress data rate limit for priority 1 frames

Egress traffic from this priority queue is shaped

according to Ta b l e 4 - 8 .

7 Reserved R/W Reserved

Do not change the default values. 0

6-0 Q2 Egress Data

Rate Limit R/W

Egress data rate limit for priority 2 frames

Egress traffic from this priority queue is shaped

according to Ta b l e 4 - 8 .

7 Reserved R/W Reserved

Do not change the default values. 0

6-0 Q3 Egress Data

Rate Limit R/W

Egress data rate limit for priority 3 frames

Egress traffic from this priority queue is shaped

according to Ta b l e 4 - 8 .

7-0 KSZ8873 Mode

Indicator RO

bit7: 1 = Reserved

bit6: 1 = 48P pkg of 2 PHY mode

bit5: 1 = Reserved 0 = Reserved

bit4: 1 = Port 3 RMII 0 = Port 3 MII

bit3: 1 = Reserved 0 = Reserved

bit2: 1 = Port 3 MAC MII 0 = Port 3 PHY MII

bit1: 1 = Port 1 Copper 0 = Port 1 Fiber

bit0: 1 = Port 2 Copper 0 = Port 2 Fiber

0x03 MLL

0x13 RLL

0x00 FLL

7-0 Reserved RO Reserved

Do not change the default values. 0x45

7-0 Reserved RO Reserved

Do not change the default values. 0x35

7-0 Reserved RO Reserved

Do not change the default values. 0x25

7-0 Reserved RO Reserved

Do not change the default values. 0x15

7 Reserved RO Reserved

Do not change the default values. 0

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 64  2017 Microchip Technology Inc.

6 Reserved RO Reserved

Do not change the default values. 0

5-0 Reserved RO Reserved

Do not change the default values. 0x18

7-6 Reserved RO Reserved

Do not change the default values. 0

5-0 Reserved RO Reserved

Do not change the default values. 0x10

7-6 Reserved RO Reserved

Do not change the default values. 0

5-0 Reserved RO Reserved

Do not change the default values. 0x08

7-4 Reserved RO Reserved

Do not change the default values. 0

3-0 Reserved RO Reserved

Do not change the default values. 0x05

7 Priority Select R/W

0 = enable straight priority with Reg 176/177/178

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 176/177/178 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 8

7 Priority Select R/W

0 = enable straight priority with Reg 175/177/178

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 175/177/178 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 4

7 Priority Select R/W

0 = enable straight priority with Reg 175/176/178

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 175/176/178 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 2

7 Priority Select R/W

0 = enable straight priority with Reg 175/176/177

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 175/176/177 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 1

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 65

KSZ8873MLL/FLL/RLL

7 Priority Select R/W

0 = enable straight priority with Reg 180/181/182

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 180/181/182 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 8

7 Priority Select R/W

0 = enable straight priority with Reg 179/181/182

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 179/181/182 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 4

7 Priority Select R/W

0 = enable straight priority with Reg 179/180/182

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 179/180/182 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 2

7 Priority Select R/W

0 = enable straight priority with Reg 179/180/181

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 179/180/181 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 1

7 Priority Select R/W

0 = enable straight priority with Reg 184/185/186

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 184/185/186 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 8

7 Priority Select R/W

0 = enable straight priority with Reg 183/185/186

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 183/185/186 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 4

7 Priority Select R/W

0 = enable straight priority with Reg 183/184/186

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 183/184/186 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 2

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 66  2017 Microchip Technology Inc.

7 Priority Select R/W

0 = enable straight priority with Reg 183/184/185

bits[7]=0 and Reg 5 bit[3]=0 for higher priority first

1 = priority ratio is 8:4:2:1 for 4 queues and 2:1 for 2

queues with Reg 183/184/185 bits[7]=1.

6-0 Reserved RO Reserved

Do not change the default values. 1

7-0 Interrupt Enable

Interrupt enable register corresponding to bits in

Note: Set register 187 first and then set register 188

(W1C= Write ‘1’ Clear) to wait the interrupt at pin 35

INTRN for the link to be changed.

0x00

P1 or P2 Link

Change (LC)

Interrupt

R/W Set to 1 when P1 or P2 link changes in analog inter-

face (W1C). 0

6-3 Reserved R/W Reserved

Do not change the default values. 0

2P3 Link Change (LC)

Interrupt R/W Set to 1 when P3 link changes in MII interface (W1C). 0

1P2 Link Change (LC)

Interrupt R/W Set to 1 when P2 link changes in analog interface

(W1C). 0

0P1 MII Link Change

(LC) Interrupt R/W Set to 1 when P1 link changes in analog interface or

MII interface (W1C). 0

7-0 Force Pause Off Iter-

ation Limit Enable R/W

1 = Enable. It is 160 ms before requesting to

invalidate flow control.

0 = Disable

7Port 2 Fiber Signal

Threshold R/W 1 = Threshold is 2.0V

0 = Threshold is 1.2V 0

6Port 1 Fiber Signal

Threshold R/W 1 = Threshold is 2.0V

0 = Threshold is 1.2V 0

5-0 Reserved RO Reserved

Do not change the default value. 0

7 Reserved RO Reserved

Do not change the default value. 0

6Internal 1.8V LDO

Disable R/W 1 = Disable internal 1.8V LDO

0 = Enable internal 1.8V LDO 0

5-0 Reserved RO Reserved

Do not change the default value. 0

7-6 Reserved RO Reserved

Do not change the default value. 00

5Insert SRC Port 1

PVID at Port 2 R/W 1= insert SRC port 1 PVID for untagged frame at

egress port 2 0

4Insert SRC Port 1

PVID at Port 3 R/W 1= insert SRC port 1 PVID for untagged frame at

egress port 3 0

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 67

KSZ8873MLL/FLL/RLL

3Insert SRC Port 2

PVID at Port 1 R/W 1= insert SRC port 2 PVID for untagged frame at

egress port 1 0

2Insert SRC Port 2

PVID at Port 3 R/W 1= insert SRC port 2 PVID for untagged frame at

egress port 3 0

1Insert SRC Port 3

PVID at Port 1 R/W 1= insert SRC port 3 PVID for untagged frame at

egress port 1 0

0Insert SRC Port 3

PVID at Port 2 R/W 1= insert SRC port 3 PVID for untagged frame at

egress port 2 0

7CPU Interface Power

Down R/W

CPU interface clock tree power down enable.

1 = Enable

0 = Disable

Note: Power save a little bit when MII interface is used

and the traffic is stopped in the power management

with normal mode

6 Switch Power Down R/W

Switch clock tree power down enable.

1 = Enable

0 = Disable

Note: Power save a little bit when MII interface is used

and the traffic is stopped in the power management

with normal mode

5-4 LED Mode Selection R/W

00 = LED0: Link/ACT, LED1: Speed

01 = LED0: Link, LED1: ACT

10 = LED0: Link/ACT, LED1: Duplex

11 = LED0: Link, LED1: Duplex

Note:

Item :: Pin State :: LED Definition

No Link High OFF

Link Low ON

100 Speed Low ON

10 Speed High OFF (Link is ON)

Full-Duplex Low ON

Half-Duplex High OFF (Link is ON)

ACT Toggle Blinking

3 LED Output Mode R/W

1 = the internal stretched energy signal from the ana-

log module will be negated and output to LED1 and

the internal device ready signal will be negated and

output to LED0.

0 = the LED1/LED0 pins will indicate the regular LED

outputs.

Note. This is for debugging purpose.

2 PLL Off Enable R/W

1 = PLL power down enable

0 = disable

Note: This bit is used in Energy Detect mode with pin

27 MII_LINK_3 pull-up in bypass mode for saving

power

1-0 Power Management

Mode R/W

Power management mode

00 = Normal Mode

01 = Energy Detection Mode

10 = Software Power Down Mode

11 = Power Saving Mode

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

KSZ8873MLL/FLL/RLL

DS00002348A-page 68  2017 Microchip Technology Inc.

4.6 Static MAC Address Table

The KSZ8873 supports both a static and a dynamic MAC address table. In response to a Destination Address (DA) look

up, the KSZ8873 searches both tables to make a packet forwarding decision. In response to a Source Address (SA)

look up, only the dynamic table is searched for aging, migration and learning purposes.

The static DA look up result takes precedence over the dynamic DA look up result. If there is a DA match in both tables,

the result from the static table is used. The entries in the static table will not be aged out by the KSZ8873.

The static table is accessed by an external processor via the SMI, SPI or I2C interfaces. The external processor per-

forms all addition, modification and deletion of static MAC table entries.

7-0 Sleep Mode R/W

This value is used to control the minimum period the

no energy event has to be detected consecutively

before the device enters the low power state when the

ED mode is on.

The unit is 20 ms. The default go_sleep time is 1.6

seconds.

0x50

7 Reserved RO Reserved

Do not change the default value. 0

6-4 Forward Invid VID

Frame R/W Forwarding ports for frame with invalid VID 3b’0

3P3 RMII Clock

Selection R/W 1 = Internal

0 = External 0

2 Reserved RO Reserved

Do not change the default value. 0

1-0 Host Interface Mode R/W

00 = I2C master mode

01 = I2C slave mode

10 = SPI slave mode

11 = SMI mode

Strapped value

of P2LED1,

P2LED0.

TABLE 4-10: FORMAT OF STATIC MAC TABLE (8 ENTRIES)

Bit Name R/W Description Default

57-57 FID R/W Filter VLAN ID – identifies one of the 16 active VLANs 0000

53 Use FID R/W 1 = use (FID+MAC) for static table look ups

0 = use MAC only for static table look ups 0

52 Override R/W

1 = override port setting “transmit enable=0” or

“receive enable=0” setting

0 = no override

51 Valid R/W 1 = this entry is valid, the lookup result will be used

0 = this entry is not valid 0

50-48 Forwarding Ports R/W

These 3 bits control the forwarding port(s):

001, forward to port 1

010, forward to port 2

100, forward to port 3

011, forward to port 1 and port 2

110, forward to port 2 and port 3

101, forward to port 1 and port 3

111, broadcasting (excluding the ingress port)

000

47-0 MAC Address R/W 48-bit MAC Address 0x0000_0000

_0000

TABLE 4-9: ADVANCED CONTROL REGISTERS (REGISTERS 96-198) (CONTINUED)

Bit Name R/W Description Default

 2017 Microchip Technology Inc. DS00002348A-page 69

KSZ8873MLL/FLL/RLL

Examples:

1. Static Address Table Read (Read the 2nd Entry)

Write to reg. 121 (0x79) with 0x10 // Read static table selected

Write to reg. 122 (0x7A) with 0x01 // Trigger the read operation

Then,

Read reg. 124 (0x7C), static table bits [57:56]

Read reg. 125 (0x7D), static table bits [55:48]

Read reg. 126 (0x7E), static table bits [47:40]

Read reg. 127 (0x7F), static table bits [39:32]

Read reg. 128 (0x80), static table bits [31:24]

Read reg. 129 (0x81), static table bits [23:16]

Read reg. 130 (0x82), static table bits [15:8]

Read reg. 131 (0x83), static table bits [7:0]

2. Static Address Table Write (Write the 8th Entry)

Write to reg. 124 (0x7C), static table bits [57:56]

Write to reg. 125 (0x7D), static table bits [55:48]

Write to reg. 126 (0x7E), static table bits [47:40]

Write to reg. 127 (0x7F), static table bits [39:32]

Write to reg. 128 (0x80), static table bits [31:24]

Write to reg. 129 (0x81), static table bits [23:16]

Write to reg. 130 (0x82), static table bits [15:8]

Write to reg. 131 (0x83), static table bits [7:0]

Write to reg. 121 (0x79) with 0x00 // Write static table selected

Write to reg. 122 (0x7A) with 0x07 // Trigger the write operation

4.7 VLAN Table

The KSZ8873 uses the VLAN table to perform look ups. If 802.1Q VLAN mode is enabled (register 5, bit 7 = 1), this

table will be used to retrieve the VLAN information that is associated with the ingress packet. This information includes

FID (filter ID), VID (VLAN ID), and VLAN membership as described in Table 4-11 .

If 802.1Q VLAN mode is enabled, KSZ8873 will assign a VID to every ingress packet. If the packet is untagged or tagged

with a null VID, the packet is assigned with the default port VID of the ingress port. If the packet is tagged with non-null

VID, the VID in the tag will be used. The look up process will start from the VLAN table look up. If the VID is not valid,

the packet will be dropped and no address learning will take place. If the VID is valid, the FID is retrieved. The FID+DA

TABLE 4-11: FORMAT OF STATIC VLAN TABLE (16 ENTRIES )

Bit Name R/W Description Default

19 Valid R/W 1 = entry is valid

0 = entry is invalid 1

18-16 Membership R/W

Specify which ports are members of the VLAN. If a DA

lookup fails (no match in both static and dynamic

tables), the packet associated with this VLAN will be

forwarded to ports specified in this field. For example,

101 means port 3 and 1 are in this VLAN.

111

15-12 FID R/W

Filter ID. KSZ8873 supports 16 active VLANs repre-

sented by these four bit fields. FID is the mapped ID.

If 802.1Q VLAN is enabled, the look up will be based

on FID+DA and FID+SA.

0x0

11-0 VID R/W IEEE 802.1Q 12 bits VLAN ID 0x001

KSZ8873MLL/FLL/RLL

DS00002348A-page 70  2017 Microchip Technology Inc.

and FID+SA lookups are performed. The FID+DA look up determines the forwarding ports. If FID+DA fails, the packet

will be broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, the FID+SA will be

learned.

Examples:

1. VLAN Table Read (read the 3rd entry)

Write to reg. 121 (0x79) with 0x14 // Read VLAN table selected

Write to reg. 122 (0x7A) with 0x02 // Trigger the read operation

Then,

Read reg. 129 (0x81), VLAN table bits [19:16]

Read reg. 130 (0x82), VLAN table bits [15:8]

Read reg. 131 (0x83), VLAN table bits [7:0]

2. VLAN Table Write (write the 7th entry)

Write to reg. 129 (0x81), VLAN table bits [19:16]

Write to reg. 130 (0x82), VLAN table bits [15:8]

Write to reg. 131 (0x83), VLAN table bits [7:0]

Write to reg. 121 (0x79) with 0x04 // Write VLAN table selected

Write to reg. 122 (0x7A) with 0x06 // Trigger the write operation

4.8 Dynamic MAC Address Table

The KSZ8873 maintains the dynamic MAC address table. Only read access is allowed.

Example:

Dynamic MAC Address Table Read (read the 1st entry and retrieve the MAC table size)

Write to reg. 121 (0x79) with 0x18 // Read dynamic table selected

Write to reg. 122 (0x7A) with 0x00 // Trigger the read operation

Then,

Read reg. 123 (0x7B), bit [7] // if bit 7 = 1, restart (reread) from this register dynamic table bits [66:64]

TABLE 4-12: FORMAT OF DYNAMIC MAC ADDRESS TABLE (1K ENTRIES)

Bit Name R/W Description Default

71 Data Not Ready RO

1 = entry is not ready, continue retrying until this bit is

set to 0

0 = entry is ready

—

70-67 Reserved RO Reserved —

66 MAC Empty RO 1 = there is no valid entry in the table

0 = there are valid entries in the table 1

65-56 Number of Valid

Entries RO

Indicates how many valid entries in the table

0x3ff means 1k entries

0x001 means 2 entries

0x000 and bit 66 = 0 means 1 entry

0x000 and bit 66 = 1 means 0 entry

00_0000_0000

55-54 Time Stamp RO 2 bits counter for internal aging —

53-52 Source Port RO

The source port where FID+MAC is learned

00 = port 1

01 = port 2

10 = port 3

51-48 FID RO Filter ID 0x0

47-0 MAC Address RO 48-bit MAC Address 0x0000_0000

_0000

 2017 Microchip Technology Inc. DS00002348A-page 71

KSZ8873MLL/FLL/RLL

Read reg. 124 (0x7C), dynamic table bits [63:56]

Read reg. 125 (0x7D), dynamic table bits [55:48]

Read reg. 126 (0x7E), dynamic table bits [47:40]

Read reg. 127 (0x7F), dynamic table bits [39:32]

Read reg. 128 (0x80), dynamic table bits [31:24]

Read reg. 129 (0x81), dynamic table bits [23:16]

Read reg. 130 (0x82), dynamic table bits [15:8]

Read reg. 131 (0x83), dynamic table bits [7:0]

4.9 Management Information Base (MIB) Counters

The KSZ8873 provides 34 MIB counters per port. These counters are used to monitor the port activity for network man-

agement. The MIB counters have two format groups: “Per Port” and “All Port Dropped Packet.”

“Per Port” MIB counters are read using indirect memory access. The base address offsets and address ranges for all

three ports are:

• Port 1, base is 0x00 and range is (0x00-0x1f)

• Port 2, base is 0x20 and range is (0x20-0x3f)

• Port 3, base is 0x40 and range is (0x40-0x5f)

Port 1 MIB counters are read using the indirect memory offsets in Ta b l e 4 - 1 4 .

TABLE 4-13: FORMAT OF “PER PORT” MIB COUNTERS

Bit Name R/W Description Default

31 Overflow RO 1 = counter overflow

0 = no counter overflow 0

30 Count Valid RO 1 = counter value is valid

0 = counter value is not valid 0

29-0 Counter Values RO Counter value 0

TABLE 4-14: PORT 1’S “PER PORT” MIB COUNTERS INDIRECT MEMORY OFFSETS

Offset Counte r Name Description

0x0 RxLoPriorityByte Rx lo-priority (default) octet count including bad packets

0x1 RxHiPriorityByte Rx hi-priority octet count including bad packets

0x2 RxUndersizePkt Rx undersize packets w/ good CRC

0x3 RxFragments Rx fragment packets w/ bad CRC, symbol errors or alignment errors

0x4 RxOversize Rx oversize packets w/ good CRC (max: 1536 or 1522 bytes)

0x5 RxJabbers Rx packets longer than 1522 bytes w/ either CRC errors, alignment

errors, or symbol errors (depends on max packet size setting)

0x6 RxSymbolError Rx packets w/ invalid data symbol and legal packet size.

0x7 RxCRCError Rx packets within (64,1522) bytes w/ an integral number of bytes and a

bad CRC (upper limit depends on max packet size setting)

0x8 RxAlignmentError Rx packets within (64,1522) bytes w/ a non-integral number of bytes

and a bad CRC (upper limit depends on max packet size setting)

0x9 RxControl8808Pkts Number of MAC control frames received by a port with 88-08h in Ether-

Type field

0xA RxPausePkts

Number of PAUSE frames received by a port. PAUSE frame is qualified

with EtherType (88-08h), DA, control opcode (00-01), data length (64B

min), and a valid CRC

0xB RxBroadcast Rx good broadcast packets (not including error broadcast packets or

valid multicast packets)

KSZ8873MLL/FLL/RLL

DS00002348A-page 72  2017 Microchip Technology Inc.

“All Port Dropped Packet” MIB counters are read using indirect memory access. The address offsets for these counters

are shown in Table 4-16.

0xC RxMulticast Rx good multicast packets (not including MAC control frames, error

multicast packets or valid broadcast packets)

0xD RxUnicast Rx good unicast packets

0xE Rx64Octets Total Rx packets (bad packets included) that were 64 octets in length

0xF Rx65to127Octets Total Rx packets (bad packets included) that are between 65 and 127

octets in length

0x10 Rx128to255Octets Total Rx packets (bad packets included) that are between 128 and 255

octets in length

0x11 Rx256to511Octets Total Rx packets (bad packets included) that are between 256 and 511

octets in length

0x12 Rx512to1023Octets Total Rx packets (bad packets included) that are between 512 and

1023 octets in length

0x13 Rx1024to1522Octets Total Rx packets (bad packets included) that are between 1024 and

1522 octets in length (upper limit depends on max packet size setting)

0x14 TxLoPriorityByte Tx lo-priority good octet count, including PAUSE packets

0x15 TxHiPriorityByte Tx hi-priority good octet count, including PAUSE packets

0x16 TxLateCollision The number of times a collision is detected later than 512 bit-times into

the Tx of a packet

0x17 TxPausePkts Number of PAUSE frames transmitted by a port

0x18 TxBroadcastPkts Tx good broadcast packets (not including error broadcast or valid multi-

cast packets)

0x19 TxMulticastPkts Tx good multicast packets (not including error multicast packets or valid

broadcast packets)

0x1A TxUnicastPkts Tx good unicast packets

0x1B TxDeferred Tx packets by a port for which the 1st Tx attempt is delayed due to the

busy medium

0x1C TxTotalCollision Tx total collision, half duplex only

0x1D TxExcessiveCollision A count of frames for which Tx fails due to excessive collisions

0x1E TxSingleCollision Successfully Tx frames on a port for which Tx is inhibited by exactly

one collision

0x1F TxMultipleCollision Successfully Tx frames on a port for which Tx is inhibited by more than

one collision

TABLE 4-15: FORMAT OF “ALL PORT DROPPED PACKET” MIB COUNTERS

Bit Name R/W Description Default

30-16 Reserved N/A Reserved N/A

15-0 Counter Value RO Counter Value 0

TABLE 4-16: “ALL PORT DROPPED PACKET” MIB COUNTERS INDIRECT MEMORY OFFSETS

Offset Counter Name Description

0x100 Port 1 TX Drop Packets TX packets dropped due to lack of resources

0x101 Port 2 TX Drop Packets TX packets dropped due to lack of resources

0x102 Port 3 TX Drop Packets TX packets dropped due to lack of resources

0x103 Port 1 RX Drop Packets RX packets dropped due to lack of resources

0x104 Port 2 RX Drop Packets RX packets dropped due to lack of resources

TABLE 4-14: PORT 1’S “PER PORT” MIB COUNTERS INDIRECT MEMORY OFFSETS

Offset Counte r Name Description

 2017 Microchip Technology Inc. DS00002348A-page 73

KSZ8873MLL/FLL/RLL

Examples:

1. MIB Counter Read (Read port 1 “Rx64Octets” Counter)

Write to reg. 121 (0x79) with 0x1c // Read MIB counters selected

Write to reg. 122 (0x7A) with 0x0e // Trigger the read operation

Then

Read reg. 128 (0x80), overflow bit [31] // If bit 31 = 1, there was a counter overflow

valid bit [30] // If bit 30 = 0, restart (reread) from this register counter bits [29:24]

Read reg. 129 (0x81), counter bits [23:16]

Read reg. 130 (0x82), counter bits [15:8]

Read reg. 131 (0x83), counter bits [7:0]

2. MIB Counter Read (Read port 2 “Rx64Octets” Counter)

Write to reg. 121 (0x79) with 0x1c // Read MIB counter selected

Write to reg. 122 (0x7A) with 0x2e // Trigger the read operation

Then,

Read reg. 128 (0x80), overflow bit [31] // If bit 31 = 1, there was a counter overflow

valid bit [30] // If bit 30 = 0, restart (reread) from this register counter bits [29:24]

Read reg. 129 (0x81), counter bits [23:16]

Read reg. 130 (0x82), counter bits [15:8]

Read reg. 131 (0x83), counter bits [7:0]

3. MIB Counter Read (Read “Port1 TX Drop Packets” Counter)

Write to reg. 121 (0x79) with 0x1d // Read MIB counter selected

Write to reg. 122 (0x7A) with 0x00 // Trigger the read operation

Then

Read reg. 130 (0x82), counter bits [15:8]

Read reg. 131 (0x83), counter bits [7:0]

4.9.1 ADDITIONAL MIB COUNTER INFORMATION

“Per Port” MIB counters are designed as “read clear.” These counters will be cleared after they are read.

“All Port Dropped Packet” MIB counters are not cleared after they are accessed and do not indicate overflow or validity;

therefore, the application must keep track of overflow and valid conditions.

To read out all the counters, the best performance over the SPI bus is (160+3) x 8 x 200 = 260 ms, where there are 160

registers, 3 overheads, 8 clocks per access, at 5 MHz. In the heaviest condition, the counters will overflow in 2 minutes.

It is recommended that the software read all the counters at least every 30 seconds.

A high performance SPI master is also recommended to prevent counters overflow.

0x105 Port 3 RX Drop Packets RX packets dropped due to lack of resources

TABLE 4-16: “ALL PORT DROPPED PACKET” MIB COUNTERS INDIRECT MEMORY OFFSETS

Offset Counter Name Description

KSZ8873MLL/FLL/RLL

DS00002348A-page 74  2017 Microchip Technology Inc.

5.0 OPERATIONAL CHARACTERISTICS

5.1 Absolute Maximum Ratings*

Supply Voltage (VIN)

(VDDA_1.8, VDDC) ....................................................................................................................................... –0.5V to +2.4V

(VDDA_3.3, VDDIO) ...................................................................................................................................... –0.5V to +4.0V

Input Voltage ............................................................................................................................................. –0.5V to +4.0V

Output Voltage........................................................................................................................................... –0.5V to +4.0V

Lead Temperature (soldering, 10s) .......................................................................................................................+260°C

Storage Temperature (TS) ...................................................................................................................... –55°C to +150°C

HBM ESD Rating......................................................................................................................................................±3 kV

*Exceeding the absolute maximum rating may damage the device. Stresses greater than the absolute maximum rating

may cause permanent damage to the device. Operation of the device at these or any other conditions above those spec-

ified in the operating sections of this specification is not implied. Maximum conditions for extended periods may affect

reliability.

5.2 Operating Ratings**

Supply Voltage

(VDDA_1.8, VDDC) ................................................................................................................................... +1.66V to +1.94V

(VDDA_3.3).............................................................................................................................................. +2.5V to +3.465V

(VDDIO) ................................................................................................................................................ +1.71V to +3.465V

Ambient Temperature (TA)

(Commercial)................................................................................................................................................0°C to +70°C

(Industrial) ................................................................................................................................................–40°C to +85°C

Junction Temperature (TJ).....................................................................................................................................+125°C

Thermal Resistance LQFP (Note 5-1) (JA) ................................................................................................. +47.24°C/W

Thermal Resistance LQFP (Note 5-1) (JC) ................................................................................................. +19.37°C/W

**The device is not guaranteed to function outside its operating ratings.

Note 5-1 No heat spreader (HS) in this package.

Note: Do not drive input signals without power supplied to the device.

 2017 Microchip Technology Inc. DS00002348A-page 75

KSZ8873MLL/FLL/RLL

6.0 ELECTRICAL CHARACTERISTICS

TA = 25°C. Specification is for packaged product only. Current consumption is for the single 3.3V supply device only and

includes the 1.8V supply voltages (VDDA, VDDC) that are provided via power output pin 56 (VDDCO).

Each PHY port’s transformer consumes an additional 45 mA at 3.3V for 100BASE-TX and 70 mA at 3.3V for 10BASE-

T at full traffic.

TABLE 6-1: ELECTRICAL CHARACTERISTICS

Parameters Symbol Min. Typ. Max. Units Note

100BASE-TX Operation (All Ports @ 100% Utilization)

100BASE-TX

(analog core + digital core

+ transceiver + digital I/O)

IDDXIO —115—mA

VDDA_3.3, VDDIO = 3.3V (single power)

Core power is provided from the

internal 1.8V LDO with input voltage

3.3V VDDIO

100BASE-TX

(3.3V Transceiver/digital

I/O + 1.8V Analog/digital

core)

IDD + IC— 32 + 83 — mA

VDDA_3.3, VDDIO = 3.3V

Analog and digital core power VDDC

using an external 1.8V LDO

10BASE-T Operation (All Ports @ 100% Utilization)

10BASE-T

(analog core + digital core

+ transceiver + digital I/O)

IDDXIO —85—mA

VDDA_3.3, VDDIO = 3.3V

Core power is provided from the

internal 1.8V LDO with input voltage

VDDIO

10BASE-TX

(3.3V Transceiver/digital

I/O + 1.8V Analog/digital

core)

IDD + IC— 14 + 72 — mA

VDDA_3.3, VDDIO = 3.3V

Analog and digital core power VDDC

using an external 1.8V LDO

Power Management Mode (with MII/RMII in Default PHY Mode)

Power Saving Mode IDD3 —96—mA

VDDA_3.3, VDDIO = 3.3V

Unplug Port 1 and Port 2

Set Register 195 bit[1,0] = [1,1]

Soft Power Down Mode IDD4 —5—mA VDDA_3.3, VDDIO = 3.3V

Set Register 195 bit[1,0] = [1,0]

Energy Detect Mode IDD5 —15—mA

VDDA_3.3, VDDIO = 3.3V

Unplug Port 1 and Port 2

Set Register 195 bit[7,0] = 0x05 with

port 3 PHY mode and bypass mode.

CMOS Inputs (VDDIO = 3.3V/2.5V/1.8V)

Input High Voltage VIH

2.0/1.8/

1.3 —— V —

Input Low Voltage VIL ——

0.8/0.7/

0.5 V—

Input Current IIN –10 — 10 µA VIN = GND ~ VDDIO

CMOS Outputs (VDDIO = 3.3V/2.5V/1.8V)

Output High Voltage VOH

2.4/2.0/

1.5 —— V I

OH = –8 mA

Output Low Voltage VOL ——

0.4/0.4/

0.3 VI

OL = 8 mA

Output Tri-State Leakage |IOZ|——10µA —

100BASE-TX Transmit (measured differentially after 1:1 transformer)

Peak Differential Output

Voltage VO0.95 — 1.05 V 100 termination across differential

output

KSZ8873MLL/FLL/RLL

DS00002348A-page 76  2017 Microchip Technology Inc.

Output Voltage Imbalance VIMB —— 2 %

100 termination across differential

output

Rise/Fall Time tr/tf3—5ns —

Rise/Fall Time Imbalance — 0 — 0.5 ns —

Duty Cycle Distortion — — — ±0.5 ns —

Overshoot — — — 5 % —

Output Jitter — — 0.7 1.4 ns Peak-to-peak

10BASE-T Receive

Squelch Threshold VSQ — 400 — mV 5 MHz square wave

10BASE-T Transmit (measured differentially after 1:1 transformer)

Peak Differential Output

Voltage VP—2.4— V

100 termination across differential

output

Output Jitter — — 1.4 11 ns Peak-to-peak

TABLE 6-1: ELECTRICAL CHARACTERISTICS (CONTINUED)

Parameters Symbol Min. Typ. Max. Units Note

 2017 Microchip Technology Inc. DS00002348A-page 77

KSZ8873MLL/FLL/RLL

7.0 T IM ING SPECIFICATIONS

7.1 EEPROM Timing

FIGURE 7-1: EEPROM INTERFACE INPUT TIMING DIAGRAM

FIGURE 7-2: EEPROM INTERFACE OUTPUT TIMING DIAGRAM

TABLE 7-1: EEPROM TIMING PARAMETERS

Symbol Parameter Min. Typ. Max. Units

tcyc1 Clock cycle — 16384 — ns

ts1 Setup time 20 — — ns

th1 Hold time 20 — — ns

tov1 Output valid 4096 4112 4128 ns

SCL

SDA

tcyc1ts1 th1

Receive Timing

SCL

SDA

tcyc1

Transmit Timing

tov1

KSZ8873MLL/FLL/RLL

DS00002348A-page 78  2017 Microchip Technology Inc.

7.2 MAC Mode MII Timing

FIGURE 7-3: MAC MODE MII TIMING - DATA RECEIVED FROM MII

FIGURE 7-4: MAC MODE MII TIMING - DATA TRANSMITTED TO MII

TABLE 7-2: MAC MODE MII TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tcyc3 Clock cycle — 400/40 — ns

ts3 Setup time 4 — — ns

th3 Hold time 2 — — ns

tov3 Output valid 7 11 16 ns

 2017 Microchip Technology Inc. DS00002348A-page 79

KSZ8873MLL/FLL/RLL

7.3 PHY Mode MII Timing

FIGURE 7-5: PHY MODE MII TIMING - DATA RECEIVED FROM MII

FIGURE 7-6: PHY MODE MII TIMING - DATA TRANSMITTED TO MII

TABLE 7-3: PHY MODE MII TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tcyc4 Clock cycle — 400/40 — ns

ts4 Setup time 10 — — ns

th4 Hold time 0 — — ns

tov4 Output valid 18 — 19 ns

KSZ8873MLL/FLL/RLL

DS00002348A-page 80  2017 Microchip Technology Inc.

7.4 RMII Timing

FIGURE 7-7: RMII TIMING - DATA RECEIVED FROM RMII

FIGURE 7-8: RMII TIMING - DATA TRANSMITTED TO RMII

TABLE 7-4: RMII TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tcyc Clock cycle — 20 — ns

t1Setup time 4 — — ns

t2Hold time 2 — — ns

tod Output delay 6 — 16 ns

REFCLK

tcyc

MTXD [1:0]

MTXEN

Transmit

Timing

REFCLK

tcyc

tod

MRXD [1:0]

MRXDV

Receive

Timing

 2017 Microchip Technology Inc. DS00002348A-page 81

KSZ8873MLL/FLL/RLL

7.5 I2C Slave Mode Timing

FIGURE 7-9: I2C INPUT TIMING

FIGURE 7-10: I2C START BIT TIMING

FIGURE 7-11: I2C STOP BIT TIMING

FIGURE 7-12: I2C OUTPUT TIMING

KSZ8873MLL/FLL/RLL

DS00002348A-page 82  2017 Microchip Technology Inc.

Note that data is only allowed to change during SCL low-time, except the start and stop bits.

TABLE 7-5: I2C TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tcyc Clock cycle 400 — — ns

tsSetup time 33 — Half-

Cycle

thHold time 0 — — ns

ttbs Start bit setup time 33 — — ns

ttbh Start bit hold time 33 — — ns

tsbs Stop bit setup time 2 — — ns

tsbh Stop bit hold time 33 — — ns

tov Output valid 64 — 96 ns

 2017 Microchip Technology Inc. DS00002348A-page 83

KSZ8873MLL/FLL/RLL

7.6 SPI Input Timing

FIGURE 7-13: SPI INPUT TIMING

TABLE 7-6: SPI INPUT TIMING PARAMETERS

Timing

Parameter Description Min. Typ. Max. Units

fCClock frequency — — 5 MHz

tCHSL SPISN inactive hold time 90 — — ns

tSLCH SPISN active setup time 90 — — ns

tCHSH SPISN active hold time 90 — — ns

tSHCH SPISN inactive setup time 90 — — ns

tSHSL SPISN deselect time 100 — — ns

tDVCH Data input setup time 20 — — ns

tCHDX Data input hold time 30 — — ns

tCLCH Clock rise time — — 1 µs

tCHCL Clock fall time — — 1 µs

tDLDH Data input rise time — — 1 µs

tDHDL Data input fall time — — 1 µs

SPIQ

SPIC

SPID

SPIS_N

High Impedance

MSB

tCHSL tSLCH

tDVCH

tCHDX

tDLDH

tDHDL

LSB

tCLCH

tCHCL

tSHCH

tCHSH

tSHSL

KSZ8873MLL/FLL/RLL

DS00002348A-page 84  2017 Microchip Technology Inc.

7.7 SPI Output Timing

FIGURE 7-14: SPI OUTPUT TIMING

TABLE 7-7: SPI OUTPUT TIMING

Parameter Description Min. Typ. Max. Units

fCClock frequency — — 5 MHz

tCLQX SPIQ hold time 0 — 0 ns

tCLQV Clock low to SPIQ valid — — 60 ns

tCH Clock high time 90 — — ns

tCL Clock low time 90 — — ns

tQLQH SPIQ rise time — — 50 ns

tQHQL SPIQ fall time — — 50 ns

tSHQZ SPIQ disable time — — 100 ns

SPID

SPIC

SPIQ

SPIS_N

tQLQH

tQHQL

LSB

tCH

tCL tSHQZtCLQV

tCLQX

 2017 Microchip Technology Inc. DS00002348A-page 85

KSZ8873MLL/FLL/RLL

7.8 Auto-Negotiation Timing

FIGURE 7-15: AUTO-NEGOTIATION TIMING

TABLE 7-8: AUTO-NEGOTIATION TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tBTB FLP burst to FLP burst 8 16 24 ms

tFLPW FLP burst width — 2 — ms

tPW Clock/Data pulse width — 100 — ns

tCTD Clock pulse to data pulse 55.5 64 69.5 µs

tCTC Clock pulse to clock pulse 111 128 139 µs

— Number of clock/data pulses per burst 17 — 33 —

Auto-Negotiation - Fast Link Pulse Timing

tPW

TX+/TX-

Clock

Pulse

Data

Pulse

Clock

Pulse

tPW

CTD

CTC

FLPW

BTB

TX+/TX-

Data

Pulse

FLP

Burst

FLP

Burst

KSZ8873MLL/FLL/RLL

DS00002348A-page 86  2017 Microchip Technology Inc.

7.9 MDC/MDIO Timing

FIGURE 7-16: MDC/MDIO TIMING

TABLE 7-9: MDC/MDIO TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tPMDC period — 400 — ns

tMD1 MDIO (PHY Input) setup to rising edge of MDC 10 — — ns

tMD2 MDIO (PHY Input) hold from rising edge of MDC 4 — — ns

tMD3 MDIO (PHY Output) delay from rising edge of MDC — 222 — ns

 2017 Microchip Technology Inc. DS00002348A-page 87

KSZ8873MLL/FLL/RLL

7.10 Reset Timing

The KSZ8873MLL/FLL/RLL reset timing requirement is summarized in Figure 7-17 and Tab l e 7 - 1 0 .

After the de-assertion of reset, wait a minimum of 100 µs before starting programming on the managed interface (I2C

slave, SPI slave, SMI, MIIM).

FIGURE 7-17: RESET TIMING

TABLE 7-10: RESET TIMING PARAMETERS

Parameter Description Min. Typ. Max. Units

tSR Stable supply voltages to reset high 10 — — ms

tCS Configuration setup time 50 — — ns

tCH Configuration hold time 50 — — ns

tRC Reset to strap-in pin output 50 — — ns

tVR 3.3V rise time 100 — — µs

SUPPLY

VOLTAGES

RST#

STRAP-IN

VALUE

STRAP-IN /

OUTPUT PIN

tVR tSR

tCS tCH

tRC

KSZ8873MLL/FLL/RLL

DS00002348A-page 88  2017 Microchip Technology Inc.

8.0 RESET CIRCUIT

Figure 8-1 shows a reset circuit recommended for powering up the KSZ8873MLL/FLL/RLL if reset is triggered only by

the power supply.

Figure 8-2 shows a reset circuit recommended for applications where reset is driven by another device (for example,

the CPU or an FPGA). At power-on-reset, R, C, and D1 provide the necessary ramp rise time to reset the KSZ8873MLL/

FLL/RLL device. The RST_OUT_N from the CPU/FPGA provides the warm reset after power-up.

FIGURE 8-1: RECOMMENDED RESET CIRCUIT

FIGURE 8-2: RECOMMENDED RESET CIRCUIT FOR CPU/FPGA RESET OUTPUT

VCC

10k

10μF

KS8873

RST

D1: 1N4148

VCC

10k

10μF

CPU/FPGA

RST_OUT_n

KS8873

RST

D1, D2: 1N4148

 2017 Microchip Technology Inc. DS00002348A-page 89

KSZ8873MLL/FLL/RLL

9.0 SELECTION OF ISOLATION TRANSFORMERS

A 1:1 isolation transformer is required at the line interface. Use one with integrated common-mode chokes for designs

exceeding FCC requirements.

Table 9-1 lists recommended transformer characteristics.

TABLE 9-1: TRANSFORMER SELECTION CRITERIA

Parameter Value Test Conditions

Turns Ratio 1 CT : 1 CT —

Open-Circuit Inductance (min.) 350 µH 100 mV, 100 kHz, 8 mA

Leakage Inductance (max.) 0.4 µH 1 MHz (min.)

Interwinding Capacitance (max.) 12 pF —

D.C. Resistance (max.) 0.9—

Insertion Loss (max.) –1.0 dB 0 MHz to 65 MHz

HIPOT (min.) 1500 VRMS —

TABLE 9-2: QUALIFIED SINGLE-PORT MAGNETICS

Manufacturer Part Number Auto MDI-X

Bel Fuse S558-5999-U7 Yes

Bel Fuse (MagJack) SI-46001 Yes

Bel Fuse (MagJack) SI-50170 Yes

Delta LF8505 Yes

LanKom LF-H41S Yes

Pulse H1102 Yes

Pulse (Low Cost) H1260 Yes

Datatronic NT79075 Yes

Transpower HB726 Yes

YCL LF-H41S Yes

TDK (MagJack) TLA-6T718 Yes

TABLE 9-3: TYPICAL REFERENCE CRYSTAL CHARACTERISTICS

Characteristic Value

Frequency 25.00000 MHz

Frequency Tolerance (max.) ±50 ppm

Load Capacitance (max.) 20 pF

Series Resistance 40

KSZ8873MLL/FLL/RLL

DS00002348A-page 90  2017 Microchip Technology Inc.

10.0 PACKAGE OUTLINE

FIGURE 10-1: 64-LEAD LQFP 10 MM X 10 MM PACKAGE

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging.

 2017 Microchip Technology Inc. DS00002348A-page 91

KSZ8873MLL/FLL/RLL

APPENDIX A: DATA SHEET REVISION HISTORY

TABLE A-1: REVISION HISTORY

Revision Section/Figure/Entry Correction

DS00002348A (1-30-17)

—

Converted Micrel data sheet KSZ8873MLL/FLL/

RLL to Microchip DS00002348A. Minor text

changes throughout.

Table 4-7 Updated the port register status 1 bit [0] descrip-

tion. Add power data for using external 1.8V LDO.

Table 3-5 Updated the note of the RMII interface operation

KSZ8873MLL/FLL/RLL

DS00002348A-page 92  2017 Microchip Technology Inc.

THE MICROCHIP WEB SITE

Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make

files and information easily available to customers. Accessible by using your favorite Internet browser, the web site con-

tains the following information:

•Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s

guides and hardware support documents, latest software releases and archived software

•General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion

groups, Microchip consultant program member listing

•Business of Micr oc hip – Product selector and ordering guides, latest Microchip press releases, listing of semi-

nars and events, listings of Microchip sales offices, distributors and factory representatives

CUSTOMER CHANGE NOTIFICATION SERVICE

Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive

e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or

development tool of interest.

To register, access the Microchip web site at www.microchip.com. Under “Support”, click on “Customer Change Notifi-

cation” and follow the registration instructions.

CUSTOMER SUPPORT

Users of Microchip products can receive assistance through several channels:

• Distributor or Representative

• Local Sales Office

• Field Application Engineer (FAE)

• Technical Support

Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales

offices are also available to help customers. A listing of sales offices and locations is included in the back of this docu-

ment.

Technical sup po rt is available through the web site at: http://microchip.com/support

 2017 Microchip Technology Inc. DS00002348A-page 93

KSZ8873MLL/FLL/RLL

PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

Device: KSZ8873

Interface: M = MII

R = RMII

F = Fibre

Package: L = 64-lead LQFP

Supply Voltage: L = Single 3.3V Supply

Temperature: blank = 0C to +70C (Commercial)

I = –40C to +85C (Industrial)

U or AM = –40C to +85C (Automotive Grade 3)

Media Type: blank = Tray

TR = Tape & Reel

Examples:

a) KSZ8873MLL

MII Interface

64-lead LQFP

Single 3.3V Supply

Commercial Temperature

Tray

b) KSZ8873MLLI

MII Interface

64-lead LQFP

Single 3.3V Supply

Industrial Temperature

Tray

c) KSZ8873MLL AM

MII Interface

64-lead LQFP

Single 3.3V Supply

Automotive Grade 3 Temperature

Tray

d) KSZ8873FLL

Fibre Interface

64-lead LQFP

Single 3.3V Supply

Commercial Temperature

Tray

e) KSZ8873FLLI

Fibre Interface

64-lead LQFP

Single 3.3V Supply

Industrial Temperature

Tray

f) KSZ8873RLL

RMII Interface

64-lead LQFP

Single 3.3V Supply

Commercial Temperature

Tray

g) KSZ8873RLLI

RMII Interface

64-lead LQFP

Single 3.3V Supply

Industrial Temperature

Tray

h) KSZ8873RLLU

RMII Interface

64-lead LQFP

Single 3.3V Supply

Automotive Grade 3 Temperature

Tray

PART NO. X X

PackageInterface

Device

Temperature

Supply

Voltage

Media

Type

Note: Add -TR to any of the parts above to indicate the

Tape & Reel option.

DS00002348A-page 94  2017 Microchip Technology Inc.

Information contained in this publication regarding device applications and the like is provided only for your convenience and may be

superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO

REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE,

MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of

Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and

hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implic-

itly or otherwise, under any Microchip intellectual property rights unless otherwise stated.

Trademarks

The Microchip name and logo, the Microchip logo, AnyRate, AVR, AVR logo, AVR Freaks, BeaconThings, BitCloud, CryptoMemory, CryptoRF,

dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck, LINK MD, maXStylus, maXTouch, MediaLB, megaAVR,

MOST, MOST logo, MPLAB, OptoLyzer, PIC, picoPower, PICSTART, PIC32 logo, Prochip Designer, QTouch, RightTouch, SAM-BA, SpyNIC,

SST, SST Logo, SuperFlash, tinyAVR, UNI/O, and XMEGA are registered trademarks of Microchip Technology Incorporated in the U.S.A. and

other countries.

ClockWorks, The Embedded Control Solutions Company, EtherSynch, Hyper Speed Control, HyperLight Load, IntelliMOS, mTouch, Precision

Edge, and Quiet-Wire are registered trademarks of Microchip Technology Incorporated in the U.S.A.

Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BodyCom, chipKIT, chipKIT logo, CodeGuard,

CryptoAuthentication, CryptoCompanion, CryptoController, dsPICDEM, dsPICDEM.net, Dynamic Average Matching, DAM, ECAN,

EtherGREEN, In-Circuit Serial Programming, ICSP, Inter-Chip Connectivity, JitterBlocker, KleerNet, KleerNet logo, Mindi, MiWi, motorBench,

MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit,

PICtail, PureSilicon, QMatrix, RightTouch logo, REAL ICE, Ripple Blocker, SAM-ICE, Serial Quad I/O, SMART-I.S., SQI, SuperSwitcher,

SuperSwitcher II, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of

Microchip Technology Incorporated in the U.S.A. and other countries.

SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.

Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries.

GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other

countries.

All other trademarks mentioned herein are property of their respective companies.

ISBN: 978-1-5224-1330-1

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:200 9 certif ication for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona; Gresham, Oregon and design centers in California

and India. The Company’s quality system processes and procedures

are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping

devices, Serial EEPROMs, microper ipher als, nonvol atil e memory and

analog product s. In addition, Microchip ’s quality system for the design

and manufacture of development systems is ISO 9001:2000 certified.

QUALITYMANAGEMENTS

YSTEM

CERTIFIEDBYDNV

== ISO/TS16949==

DS00002348A-page 95  2017 Microchip Technology Inc.

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11/07/16