Data Sheet 5 V 1.0D3, 2001-03
Preliminary
82C900Standalone TwinC AN Controller
82C900
Architectural Overview
The Standalone TwinCAN device provides several submodules to control the data flow
and to configure the peripheral function:
Features:
• Two interface channels are implemented for the communication with a host device:
– the Multiplexed Data/Address Bus can be used by an external CPU to read and
write the TwinCAN’s internal registers for initial configuration and control during
normal operation. The standard Infineon Bus Mode and the Motorola Bus Mode can
be handled.
– alternativel y, a Synchronous Seri al Channel (SSC) may be selected to re ad out the
initial TwinCAN’s register configuration from a serial EEPROM. The SSC can be
also used by an external control device (microcontroller, CPU, etc.) in order to
exchange control and status information.
• Both communication channels are based on byte transfers. In order to minimize the
communication o verhead, all inter nal 16 bit and 32 bit wide regi sters can be a ccessed
in Page Mode requiring only one address byte.
• Powerful initialization mechanism for all registers, the device can be configured via
EEPROM, based on CAN messages or by an external host device.
• Additional input/output functionality controlled by CAN messages. The transmission of
CAN messages can be triggered by input pins if the SSC is used for communication.
• The clock control unit can be supplied wi th an exter nal clock. Altern atively, an on-chip
oscillator may be used to generate a clock driving also an external device via an output
pin.
• Power Saving features have been implemented. A Sleep Mode and a Power-Down
Mode can be activated in order to mini mize the power consumption. The clock control
of the device can be controlled by CAN messages.
• The inter nal power sa ving status can be moni tored at output pi ns. This all ows flexible
and powerful system partitioning.
• The Device Contr oller unit generates the in ternal targ et address by concatenati ng the
contents of the PAGE register with the address delivered by the appropriate host read/
write access.
• The Interrupt Control unit passes the interrupt requests generated by the TwinCAN
controller to the external host via selectable output pins.
• The Port Control unit can be used to select the required functionality of the port pins
operating as communication channel, CAN node function monitor, interrupt request
line or general purpose I/O. Furthermore, the slew rate of pins configured for output
operation can be adjusted via this module.