can18xx8.h

一个CAN学习程序

 * PreCondition:    MCU must be in Configuration mode or else these
 *                  values will be ignored.
 *
 * Input:           SJW     - SJW value as defined in 18CXX8 datasheet
 *                              (Must be between 1 thru 4)
 *                  BRP     - BRP value as defined in 18CXX8 datasheet
 *                              (Must be between 1 thru 64)
 *                  PHSEG1  - PHSEG1 value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  PHSEG2  - PHSEG2 value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  PROPSEG - PROPSEG value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  flags   - Value of type enum CAN_CONFIG_FLAGS
 *
 * Output:          CAN bit rate is set.
 *                  All masks registers are set '0'
 *                  to allow all messages.
 *                  Filter registers are set according to flag value.
 *                  If (config & CAN_CONFIG_VALID_XTD_MSG)
 *                      Set all filters to XTD_MSG
 *                  Else if (config & CONFIG_VALID_STD_MSG)
 *                      Set all filters to STD_MSG
 *                  Else
 *                      Set half of the filters to STD while rests to
 *                      XTD_MSG.
 *
 * Side Effects:    All pending transmissions are aborted.
 ********************************************************************/
void CANInitialize(BYTE SJW,
                    BYTE BRP,
                    BYTE PHSEG1,
                    BYTE PHSEG2,
                    BYTE PROPSEG,
                    enum CAN_CONFIG_FLAGS config);

//////////////////////////////////////////////////////////////////////


/*********************************************************************
 * Function:        void CANSetOperationMode(CAN_OP_MODE mode)
 *
 * PreCondition:    None
 *
 * Input:           mode    - Operation mode code
 *                            must be of type enum CAN_OP_MODES
 *
 * Output:          MCU is set to requested mode
 *
 * Side Effects:    None
 *
 * Note:            This is a blocking call.  It will not return until
 *                  requested mode is set.
 ********************************************************************/
void CANSetOperationMode(enum CAN_OP_MODE mode);


//////////////////////////////////////////////////////////////////////


/*********************************************************************
 * Macro:           void CANSetOperationModeNoWait(CAN_OP_MODE mode)
 *
 * PreCondition:    None
 *
 * Input:           mode    - Operation mode code
 *                            must be of type enum CAN_OP_MODES
 *
 * Output:          MCU is set to requested mode
 *
 * Side Effects:    None
 *
 * Note:            This is a non-blocking call.
 *                  It does not verify that
 *                  CAN module is switched to requested mode or not.
 *                  Caller must use CANGetOperationMode() to verify
 *                  correct operation mode before performing mode
 *                  specific operation.
 *
 ********************************************************************/
#define CANSetOperationModeNoWait(mode) (CANCON = mode)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           CAN_OP_MODE CANSetOperationMode()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          Current operational mode of CAN module is returned
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANGetOperationMode() (CANCON & CAN_OP_MODE_BITS)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Function:        void CANSetBaudRate(BYTE SJW,
 *                                      BYTE BRP,
 *                                      BYTE PHSEG1,
 *                                      BYTE PHSEG2,
 *                                      BYTE PROPSEG,
 *                                      enum CAN_CONFIG_FLAGS flags)
 *
 * PreCondition:    MCU must be in Configuration mode or else these
 *                  values will be ignored.
 *
 * Input:           SJW     - SJW value as defined in 18CXX8 datasheet
 *                              (Must be between 1 thru 4)
 *                  BRP     - BRP value as defined in 18CXX8 datasheet
 *                              (Must be between 1 thru 64)
 *                  PHSEG1  - PHSEG1 value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  PHSEG2  - PHSEG2 value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  PROPSEG - PROPSEG value as defined in 18CXX8
 *                            datasheet
 *                              (Must be between 1 thru 8)
 *                  flags   - Value of type enum CAN_CONFIG_FLAGS
 *
 * Output:          CAN bit rate is set as per given values.
 *
 * Side Effects:    None
 *
 ********************************************************************/
void CANSetBaudRate(BYTE SJW,
                     BYTE BRP,
                     BYTE PHSEG1,
                     BYTE PHSEG2,
                     BYTE PROPSEG,
                     enum CAN_CONFIG_FLAGS);

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Function:        void CANSetMask(enum CAN_MASK code,
 *                                  unsigned long val,
 *                                  enum CAN_CONFIG_FLAGS type)
 *
 * PreCondition:    MCU must be in Configuration mode.  If not, all
 *                  values
 *                  will be ignored.
 *
 * Input:           code    - One of CAN_MASK value
 *                  val     - Actual mask register value.
 *                  type    - Type of message to filter either
 *                            CAN_CONFIG_XTD_MSG or CAN_CONFIG_STD_MSG
 *
 * Output:          Given value is bit adjusted to appropriate buffer
 *                  mask registers.
 *
 * Side Effects:    None
 ********************************************************************/
void CANSetMask(enum CAN_MASK code,
                unsigned long Value,
                enum CAN_CONFIG_FLAGS type);

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Function:        void CANSetFilter(enum CAN_FILTER code,
 *                                    unsigned long val,
 *                                    enum CAN_CONFIG type)
 *
 * PreCondition:    MCU must be in Configuration mode.  If not, all
 *                  values will be ignored.
 *
 * Input:           code    - One of CAN_FILTER value
 *                  val     - Actual filter register value.
 *                  type    - Type of message to filter either
 *                            CAN_CONFIG_XTD_MSG or CAN_CONFIG_STD_MSG
 *
 * Output:          Given value is bit adjusted to appropriate buffer
 *                  filter registers.
 *
 * Side Effects:    None
 ********************************************************************/
void CANSetFilter( enum CAN_FILTER code,
                    unsigned long Value,
                    enum CAN_CONFIG_FLAGS);

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Function:        BOOL CANSendMessage(unsigned long id,
 *                                  BYTE *Data,
 *                                  BYTE DataLen,
 *                                  enum CAN_TX_MSG_FLAGS MsgFlags)
 *
 * PreCondition:    None
 *
 * Input:           id          - CAN message identifier.
 *                                Only 11 or 29 bits may be used
 *                                depending on standard or extended
 *                                message type.
 *                  Data        - Data bytes of upto 8 bytes in length
 *                  DataLen     - Data length from 1 thru 8.
 *                  MsgFlags    - One or CAN_TX_MSG_FLAGS values ANDed
 *                                together
 *
 * Output:          If at least one empty transmit buffer is found,
 *                  given message is queued to be transmitted. If none
 *                  found FALSE value is returned.
 *
 * Side Effects:    None
 *
 ********************************************************************/
BOOL CANSendMessage(unsigned long id,
                     BYTE *Data,
                     BYTE DataLen,
                     enum CAN_TX_MSG_FLAGS MsgFlags);

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Function:        BOOL CANReceiveMessage(unsigned long *id,
 *                                  BYTE *Data,
 *                                  BYTE *DataLen,
 *                                  enum CAN_RX_MSG_FLAGS *MsgFlags)
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          id          - CAN message identifier.
 *                  Data        - Data bytes of upto 8 bytes in length
 *                  DataLen     - Data length from 1 thru 8.
 *                  MsgFlags    - One or CAN_RX_MSG_FLAGS values ANDed
 *                                together
 *
 * Output:          If at least one full receive buffer is found,
 *                  it is extrated and returned. If none found FALSE
 *                  value is returned.
 *
 * Side Effects:    None
 *
 ********************************************************************/
BOOL CANReceiveMessage(unsigned long* id,
                        BYTE *Data,
                        BYTE *DataLen,
                        enum CAN_RX_MSG_FLAGS *MsgFlags);

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BYTE CANGetTxErrorCount()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          Current transmit error count as defined by
 *                  CAN specifications.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANGetTxErrorCount()    (TXERRCNT)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BYTE CANGetRxErrorCount()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          Current receive error count as defined by
 *                  CAN specifications.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANGetRxErrorCount()    (RXERRCNT)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BOOL CANIsBusOff()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          TRUE if CAN Module is off due to excessive error
 *                  FALSE is it is not off.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANIsBusOff()           (COMSTAT_TXB0)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BOOL CANIsTxPassive()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          TRUE if CAN transmit module is error passive as
 *                  defined by CAN specifications.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANIsTxPassive()        (COMSTAT_TXBP)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BYTE CANIsRxPassive()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          TRUE if CAN receive module is error active as
 *                  defined by CAN specifications.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANIsRxPassive()        (COMSTAT_RXBP)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           void CANAbortAll()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          None
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANAbortAll()           (CANCON_ABAT = 1)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BOOL  CANIsRxReady()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          TRUE if at least one of the CAN receive buffer is
 *                  empty FALSE if none receive buffers are empty.
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANIsRxReady()          (RXB0CON_RXFUL || RXB1CON_RXFUL)

//////////////////////////////////////////////////////////////////////

/*********************************************************************
 * Macro:           BOOL CANIsTxReady()
 *
 * PreCondition:    None
 *
 * Input:           None
 *
 * Output:          TRUE if at least one CAN transmit buffer is empty
 *                  FALSE if all CAN transmit buffers are full
 *
 * Side Effects:    None
 *
 ********************************************************************/
#define CANIsTxReady()          (!TXB0CON_TXREQ || \
                                 !TXB1CON_TXREQ || \
                                 !TXB2CON_TXREQ )

#endif      // CAN18XX8_H