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PROCESSOR-SDK-J721S2: About MCU_CAN BUSOFF

Part Number: PROCESSOR-SDK-J721S2
Other Parts Discussed in Thread: TDA4VL

Hi,

SDK: 8.6     CORE: MCU1_0

I ran into the following problem while debugging MCU_CAN1 for TDA4VL:
In loopback mode, CAN is sent and received normally. However, after the loopback mode is turned off, our CAN reports BUSOFF error, resulting in CAN data cannot be sent. What we can confirm is that our CAN_H and CAN_L are not short-connected, and we have set the STBZ pin of TJA1044 low.
1. How do we determine whether this phenomenon is a software problem or a hardware problem?
2, the void CanIf_ControllerBusOff(uint8 ControllerId) function in MCAL only provides the CAN channel corresponding to BUSOFF, how do we determine the type of BUSOFF?
3. Our hardware design is shown as follows. Is there any problem with the help of experts from TI?

Regards,

Bingxian

  • Hello,

    If you are testing Internal loopback mode , it wont go through your CAN transceivers so you cannot confirm from loop back mode everything is fine.Are you using a custom developed board rather than EVM?  

    I need more details to figure out whether its SW or HW problem.

    What is the other end of the CAN node is connected to ? 

    Within how much time is the CAN BUS reporting BUSOFF error ?

    You have examples in SDK if you want to test on your board ?

    Regards

    Tarun Mukesh

  • Hi, Tarun Mukesh

    If you are testing Internal loopback mode , it wont go through your CAN transceivers so you cannot confirm from loop back mode everything is fine.Are you using a custom developed board rather than EVM?  

    Instead of using EVM, we use our own board

    What is the other end of the CAN node is connected to ? 

    The latest news is that I have disconnected the two pins of MCU_MCAN1_TX MCU_MCAN1_RX from the peripheral circuit, This means that the two pin periphery, C23 F26, is without any circuit

    Within how much time is the CAN BUS reporting BUSOFF error ?

    An error occurs when Can_Write is called,
    After debugging, I found that the Can_mcanProcessISR function under Can_Mcan.c was giving a busoff error

    You have examples in SDK if you want to test on your board ?

    The CAN code I'm using now is ported from the MCAL example in the SDK

    Regards,

    Bingxian

  • Hello,

    Which SDK version are you on ? We have done some fix in MCAN driver related to bus off issue.

    Regards

    Tarun Mukesh

  • Hi, Tarun Mukesh

    I have found out the reason. It is the hardware problem of our board. Thank you for your answer

    Regards,

    Bingxian