Hi - I have a system that consists of one Atmel SAM7X256 connected via CAN to 6 Microchip MCP2515 chips. The MCP2515s have 20MHz clocks, and the SAM7X256 has a 55MHz clock. I have the CAN bus running at 1MHz right now, but the chips aren't perfectly matched. Specifically, the SAM7X256 uses 11TQ, while the MCP2515 uses 10TQ. I had to do this as otherwise I'd have to have fractional baudrate divisors, which obviously is not possible. Communication is perfect without any CAN errors whatsoever - but I'm just wondering - is this allowed within spec? Or am I just getting lucky? I have the propagation segment on the SAM7X256 1TQ longer than on the MCP2515. Is this the best part to lengthen? These are my settings:
MCP2515: syncseg = 1TQ PS1 = 3TQ PS2 = 3TQ propseg = 3TQ
AT91SAM7X256: syncseg = 1TQ PS1 = 3TQ PS2 = 3TQ propseg = 4TQ
Thanks!
-Mike