We use TJA1044 CAN Transceiver and S12Z chip for CAN bus wake-up experiment. According to the TJA1044 chip manual: WAKE-UP FILTER will filter out some level changes of CAN bus. After the wake-up event is triggered, Rx will reflect CAN The level of the bus changes. S12 cannot correctly receive the information contained in the CAN wake-up frame, because the wake-up event (dominant-recessive-dominant) is partially filtered out by the CAN Transceiver. In fact, S12 correctly receives all the information of the CAN wake-up frame. how about this? Our baud rate is 500kbit/s.Thanks for browsing this issue.
How many active nodes do you have on the bus? If just sender and sleeping S12, then sending node doesn't receive ack and resends message until some other node acks it. So try connecting additional non-sleeping node and see what happens to wake message.
Thank you very much,I have solved the problem.
I add an another active node in the CAN bus,the new node ack the wake-up frame,
the S12 is waken but doesn't receive the correct frame.
If there are only two node in the CAN bus,S12 will receive the content of wake-up frame.