Figure 12-12: The CAN ports on the 80C390 CPU
CAN0 uses pins 20 (CAN0 receive) and 21 (CAN0 transmit) of the 80C390 and pins 10 (CAN0 transmit) and 11 (CAN0 receive) of the TINI SIMM connector. The Dallas Semiconductor E10 and E20 socketboards have areas for the CAN transceiver, terminator and connector header.
Figure 12-13: CAN0
You will need a CAN transceiver for each of CAN0 and CAN1 if you intend to use both CAN ports. Dallas Semiconductor specifies the Philips PCA82C250 CAN controller5 interface. Texas Instruments offers the Unitrode UC5350 Can Transceiver6 and has declared it “pin compatible with PCA82C250 and DeviceNet, SDS.” The schematic (Figure 12-13) shows an optional CAN bus terminator (a 120Ω resistor) that can be included on the bus with a jumper.
CAN1 uses pins 18 (CAN1 transmit) and 19 (CAN1 receive) of the 80C390 and pins 14 (CAN1 transmit) and 15 (CAN1 receive) of the TINI SIMM connector. CAN1 shares the same CPU pins as serial1 and the 1-Wire port. To use CAN1 you will need to disable the 1-Wire port by tying the EN2480 pin on the SIMM (pin 26 on the 72 pin SIM) to ground.
CAN1 on Protoboard