TMS320F280039: TMS320F280039:MCAN Busoff Recorvery Error

liu Gaosong

Part Number: TMS320F280039

Tool/software:

HI,

When we were conducting the Busoff test of the MCAN module (the way to trigger busoff is to continuously short-circuit CAN-H and CAN-L), after reinitializing MCAN, the application layer attempted to send a message. Due to the continuous short-circuiting of CAN-H and CAN-L, it would enter busoff again. However, there may occasionally be another busoff interruption after an interval of approximately 2.8 ms, as shown in the last descending section of the blue line in the following figure. What could be the reason for this?

5 months ago

0 Joseph Casuga 5 months ago

TI__Mastermind 38740 points

Hi Liu,

This is the expected behavior, right? The fault is still there where CAN_L and CAN_H are still shorted after the MCAN initialization at the detection of bus off. The TEC continues to increment again to reach the bus off threshold. TEC counter will only stop incrementing if the source of the error (in this case CAN bus short) is eliminated.

Regards,

Joseph

0 Joseph Casuga 5 months ago in reply to Joseph Casuga

TI__Mastermind 38740 points

Hi Liu,

Sorry, i was not understanding the issue with bus off but Terry's explanation helped in his post: TMS320F280039: why bus off recover and trigger interrupt while can bus keep shortage . To avoid confusion, i will mark this post closed but let us continue to follow this up using Terry's post.

Best regards,

Joseph

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TMS320F280039: TMS320F280039:MCAN Busoff Recorvery Error