SAK82C900 Datasheet, PDF (9/29 Pages) Infineon Technologies AG – Standalone TwinCAN Controller

82C900
Preliminary
Operation without Host Device
The standalone functionality comprises an additional mode, leading to a low-cost
system, which does not require any external host device. This mode can be selected by
setting the input pins MODE0 and MODE1 to 1. The best solution are pull-up resistors
(about 10 to 47 kOhm). After the reset phase, the MODE pins can be enabled to control
the power-down functionality of the entire connected system by indicating the internal
status of two clock control bits. The power-down functionality can run completely via
CAN messages (sleep and wake-up by CAN messages).
The initialization sequence is automatically started from an external non-volatile
memory, a serial (SPI-compatible) EEPROM. The data, which is read out from the
EEPROM permits the user to initialize the registers with the desired values in a freely
programmable order. Changes in the application only lead to modified data stored in the
non-volatile memory.
For example, the bit timing, one message object and some control registers are set up
via the data read from the EEPROM. Then, the initialization can continue via CAN
messages.
The 8 remaining I/O pins from the unused parallel interface are controlled by a port
control logic and can be used as I/O extension. These lines can be read or written by
CAN messages.
CAN Bus A
CAN Bus B
Transceiver
Transceiver
RXDCA,
TXDCA
RXDCB,
TXDCB
82C900
TwinCAN Module
Clock Control
Port Control Serial Interface
Device
Control
I/O7..0
Input/Output
extension
CTRL3..0
Serial
EEPROM
Power-Down
Indication
Figure 4 Connection to a Serial EEPROM
Data Sheet
9
V 1.0D3, 2001-03