LAUNCHXL-F280025C: 關於CAN bus receive data的DLC

以下函数可用于使用 IFx 寄存器读取 DLC 字段：

//*****************************************************************************
//
// CAN_readMessageWithDLC
//
//*****************************************************************************
bool CAN_readMessageWithDLC(uint32_t base,
                           uint32_t objID,
                           uint16_t *msgData,
                           uint16_t *msgLen)
{
    bool status;

    //
    // Check the pointers.
    //
    ASSERT(msgLen != 0U);

    //
    //Read the message first this fills the IF2 registers
    //with received message for that mailbox
    //
    status = CAN_readMessage(base, objID, msgData);
    //
    // See if there is new data available.
    //
    if(status == true)
    {
        *msgLen = (HWREG_BP(base + CAN_O_IF2MCTL) & CAN_IF2MCTL_DLC_M);
    }

    return(status);
}