TMS320F280049: 你好，关于280049的CAN通讯例程

//*****************************************************************************
//
//! Reads the data and Message ID in a Message Object
//!
//! \param base is the base address of the CAN controller.
//! \param objID is the object number to read (1-32).
//! \param frameType is a pointer to the CAN_MsgFrameType to store the message 
//!        type that has been received in the mailbox 
//! The \e frameType parameter shall be filled as of the following values:
//! - \b CAN_MSG_FRAME_STD - Standard 11 bit identifier
//! - \b CAN_MSG_FRAME_EXT - Extended 29 bit identifier
//! This parameter is filled when return value is true for this function.
//! \param msgID is a pointer to storage for the received Message ID
//! Filled when the return value is true for this function.
//! \param msgData is a pointer to the array to store the message data
//! Filled with read Data when the return value is true for this function.
//!
//! This function is used to read the data contents and the Message ID 
//! of the specified message object in the CAN controller.The Message returned 
//! is stored in the \e msgID parameter and its type in \e frameType parameter.
//! The data returned is stored in the \e msgData parameter.
//!
//! \note
//! -# The message object requested by the \e objID must first be setup
//! using the CAN_setupMessageObject() function.
//!
//! \return Returns \b true if new data was retrieved, else returns
//! \b false to indicate no new data was retrieved.
//
//*****************************************************************************
extern bool CAN_readMessageWithID(uint32_t base,
                                  uint32_t objID,
                                  CAN_MsgFrameType *frameType,
                                  uint32_t *msgID,
                                  uint16_t *msgData);

struct CAN_IF1ARB_BITS {                // bits description
    bp_32 ID:29;                        // 28:0 `
    bp_32 Dir:1;                        // 29 Message Direction
    bp_32 Xtd:1;                        // 30 Extended Identifier
    bp_32 MsgVal:1;                     // 31 Message Valid
};