CANFD Bus_Off recovery time

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Ana0211
Level 2
Level 2
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Hello,

I am having a problem related to the Bus_Off recovery time. Can you please tell me what is the nominal value for this delay please ?

I am currently seeing around 18 ms in between the moment when I set the CCCR.INIT to 0 in order to recover and the Bus_Off status change interrupt in order to exit the Bus_Off.

I don't know if the problem comes from my integration (I am not using the SDK for the CAN module) or from something else that I am missing.

Thank you !

Ana

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1 Reply
Pranith
Moderator
Moderator
Moderator
100 sign-ins 50 sign-ins 25 replies posted

Hello @Ana0211 ,

1. When bus off is detected, CAN FD controller will set CCR.INIT to 1. Stopping all bus activities.
2. In order to recovery the bus off, Bus off recovery sequence needs to be performed.
It is done by clearing the CCR.INIT (i.e. CCR.INIT written to 0), which starts the timer for waiting 129 occurrences of Bus Idle (129 x 11 consecutive recessive bits) before resuming normal operation.
3. At the end of the Bus off recovery sequence (confirmed by reading CCR.INIT equal to 0), the Receive and Transmit Error Counters will be reset.

Could you let us know if you are using the Sample driver library?

Regards,

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