TCAN4550: How to disable TCAN4550 Auto Bus_off function

Hi，Hao

We have found out that the canfd network has entered the bus_ At present, the solution has been found. Just set the init register to recover. Thank you very much

Regards,

Hanc

Hi Hanc,

Out of curiosity, are you using the default TI driver to work with the can?

I'm currently resetting the device any time the device encounters Bus_off flag when it transmits. I didn't enable the interrupt for BO, so I only reset right before the transmission (ofc if the BO is set to 1).

I'd imagine you have the interrupt enabled and perhaps when it happens you write the CCCR.INIT = 0 to set it back to normal operation?

something like this in the interrupt handler?

    TCAN4x5x_Device_Interrupts dev_ir = {0}; // Define a new Device IR object for device (non-CAN) interrupt
                                             // checking
    TCAN4x5x_MCAN_Interrupts mcan_ir = {0};  // Setup a new MCAN IR object for easy interrupt checking
    TCAN4x5x_Device_ReadInterrupts(&dev_ir); // Read the device interrupt register
    TCAN4x5x_MCAN_ReadInterrupts(&mcan_ir);  // Read the interrupt register

    if (dev_ir.SPIERR)                 // If the SPIERR flag is set
        TCAN4x5x_Device_ClearSPIERR(); // Clear the SPIERR flag
    if (mcan_ir.BO)
    {
        // Bus off event handling. Writing the CCCR should write init
        TCAN4x5x_MCAN_CCCR_Config cccrConfig = {0}; // the first bit will be 0 CCCR.INIT
        AHB_WRITE_32(REG_MCAN_CCCR, cccrConfig.word);
    }

Thank you

Hi，Hao

We don't use interrupt. We poll canfd status by periodic self-test. When status register PSR appears busoff state, we write CCCR.INIT to zero in time

   psr = AHB_READ_32(t_SpiBaseAddrForCANFD,REG_MCAN_PSR);
    //检查状态是否正常
    if(_Check4550Status(TCAN4550Index))
    {
        //状态寄存器异常,停止发送
        drvLog(LOG_ERR,"CANFD_%d read status error ! ! ! ! ! !\r\n",TCAN4550Index);
        return DRVSTATE_BUSERR;//bus error
    }
    else if((psr & 0x80) == 0x80)//can总线已自动关闭
    {
        drvLog(LOG_ERR,"can %d bus_off\r\n",TCAN4550Index);

        cccr = AHB_READ_32(t_SpiBaseAddrForCANFD,REG_MCAN_CCCR);
        drvLog(LOG_DEBUG,"can %d cccr 0x%x\r\n",TCAN4550Index,cccr);
        cccr &= ~(1<<0);
        AHB_WRITE_32(t_SpiBaseAddrForCANFD,REG_MCAN_CCCR,cccr);
        return DRVSTATE_BUSOFF;
    }