jenny roma

s12xdp512 CAN modules's init problem.

Discussion created by jenny roma on Sep 18, 2006
Latest reply on Sep 30, 2009 by Kai Jiang
Anyone can help me ?
All the five CAN modules of my S12XDP512, only the CAN4 and CAN2 can be inited correctly.(I didn't set the LOOPB bit).
When I set the LOOPB bit,all of the five CANs can inited correctly.
The CAN4 is connected to MC33388,and can transmit and receive messages.
Both the another four CAN modules connected with TJA1040.but none of them can work .even the CAN2 module(it can inited correctly). when I use a probe to test the signals of CAN2TX and CAN2RX pins,I found nothing.but by chance i short the CAN2TX and CAN2RX,I get the bus signals,and the buadrate was just what I desired.

I do emphasize that point that all the four modules are accordant in principle and hardware circiut.
why the CAN2 can inited but the another three can not?
why the CAN2 can inited normally but can not transmitmessages?
I get no ideas and really puzzled.