Hello Expert,
I have question regarding WUP feature.
WUP require specific length dominant and recessive pattern to trigger it.
I think this pattern will not be triggered by general communication pattern on CAN bus but I don't have confidence.
Would you tell me whether there is triggered WUP by pattern?
Thank you and best regards,
Kazuki Kuramochi
Kazuki,
It is possible for regular communication to trigger the WUP. This is actually an intended use case for the WUP and I will explain why later. First you are correct the WUP has a filter on it. On the TCAN1042 the WUP filter is:
This filter time is within the communication speed of CAN but this is an intended use case. The idea here is that if your CAN frame has a filtered dominant, filtered recessive, and filtered dominant pulse then you can send the same CAN frame twice. Once to wake the device up and again for the device to actually receive the message. So you don't need to send an explicit WUP on the bus. If you find that the message is not intended for you then you can just put your device back to standby.
I hope this makes sense.
Best,
Chris
