TMS320F28035: CAN BUS OFF question

Huihuang Chen

Expert 4060 points

Part Number: TMS320F28035

Hi Champ,

I have following question about CAN bus off:

1.bus-off flag BO will be cleared automatically or not if CAN exit the bus off condition?

1.if ABO is 0, what is the SW procedure to exit the bus off ?

over 3 years ago

0 Hareesh Janakiraman over 3 years ago

TI__Guru* 95315 points

Huihuang Chen said:
1.bus-off flag BO will be cleared automatically or not if CAN exit the bus off condition?

A more reliable indicator of bus-off condition than CANES.BO is the CANMC.CCR bit. This is because, in CANES register, the first bit that gets set will freeze the other bits until the first bit is cleared. CANMC.CCR bit will get set upon bus-off.

Huihuang Chen said:
1.if ABO is 0, what is the SW procedure to exit the bus off ?

The CCR bit must be cleared.

0 Huihuang Chen over 3 years ago in reply to Hareesh Janakiraman

TI__Expert 4060 points

Hareesh,

Could you help to confirm the CANES.BO will be cleared automatically or not if CAN exit the bus off condition?

0 Hareesh Janakiraman over 3 years ago in reply to Huihuang Chen

TI__Guru* 95315 points

As explained in my previous thread. CANES.BO is not a reliable indicator of bus-off. Application should use CANMC.CCR instead.

0 Huihuang Chen over 3 years ago in reply to Hareesh Janakiraman

TI__Expert 4060 points

I understood use CANMC.CCR instead.

But i just want to confirm CANES.BO will be cleared automatically or not if CAN exit the bus off condition?

0 Hareesh Janakiraman over 3 years ago in reply to Huihuang Chen

TI__Guru* 95315 points

No, CANES.BO will not be cleared automatically when the node exits bus-off.

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TMS320F28035: CAN BUS OFF question