TMS320F280049C: Can communication and interrupt exception

Cherry Zhou

Hi team,

Here's an issue from the customer may need your help:

The customer made some modifications to the control routine in speed mode to run the motor application and found that can communication was lost in a repeated start-stop condition.

There are currently two known bugs:

1) Set the ABO bits of the can related registers to enable automatic Busoff state recovery, but do not configure an ABO_time of the associated can_ABOTR register (as required by the application note);

2) In addition, communication is executed in a time slice where the counter is configured in the main interrupt, and CAN communication is suspended if the main interrupt halts (previously, a main interrupt was interrupted due to the TZ signal, so a signal feed dog was generated in the main interrupt to account for a master interrupt exception caused by the TZ signal). And the reason for the main interrupt being stopped is not yet certain.

Which of the above bugs is more likely to cause this issue? Could you help check this case? Thanks.

Best Regards,

Cherry

over 3 years ago

0 Cherry Zhou over 3 years ago

TI__Mastermind 22235 points

Hi,

May I know is there any update? Thanks.

Regards,

Cherry

0 Hareesh Janakiraman over 3 years ago

TI__Guru* 95315 points

Cherry Zhou said:
There are currently two known bugs:

By “bugs”, I presume you are referring to bugs in the customer code, not the DCAN module itself.

In any case, it is extremely difficult for us to debug cases like this, since it warrants a thorough knowledge of the application firmware, which we don't have. With the provided description, it is not even possible to provide debug ideas.

0 Cherry Zhou over 3 years ago in reply to Hareesh Janakiraman

TI__Mastermind 22235 points

Hi Hareesh,

Thanks for your support.

The customer just wants to know the specific circumstances where the interruption was suspended, for example, the mechanism for the suspension. And then they're going figure out the cause as in this direction.

The customer's current interrupt is PWM triggered ADC, ADC triggered main interrupt.

Also, the customer sets the ABO bit in the can related registers to enable automatic Busoff state recovery, but does not configure an ABO_time in the associated can_ABOTR register. What are the abnormal States of the DCAN module itself?

Thanks and regards,

Cherry

0 Hareesh Janakiraman over 3 years ago in reply to Cherry Zhou

TI__Guru* 95315 points

Cherry Zhou said:
The customer just wants to know the specific circumstances where the interruption was suspended, for example, the mechanism for the suspension.

There are numerous registers/bits (both at the peripheral level and at the PIE level) that determine whether or not an interrupt will be serviced. Please refer to section 3.5 in the TRM.

Cherry Zhou said:
Also, the customer sets the ABO bit in the can related registers to enable automatic Busoff state recovery, but does not configure an ABO_time in the associated can_ABOTR register.

That is OK. A default value will be used.

Cherry Zhou said:
What are the abnormal States of the DCAN module itself?

The different types of errors are listed in the description for CANES register.

0 Cherry Zhou over 3 years ago in reply to Hareesh Janakiraman

TI__Mastermind 22235 points

Hi,

Hareesh Janakiraman said:
That is OK. A default value will be used.

If not configured, the default value is 0. What does the default setting you mentioned do? And what is the default value?

Thanks and regards,

Cherry

0 Hareesh Janakiraman over 3 years ago in reply to Cherry Zhou

TI__Guru* 95315 points

Default recovery time is 129 occurrences of 11-bit recessive times. 11-bits refer to the gap between two frames. You cannot shorten this recovery time.

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TMS320F280049C: Can communication and interrupt exception