CAN->sMsgObj[msg_if].MCR = CAN_MCR_TXIE | CAN_MCR_EOB;

  CAN->sMsgObj[msg_if].DA1R = 0;
  CAN->sMsgObj[msg_if].DA2R = 0;
  CAN->sMsgObj[msg_if].DB1R = 0;
  CAN->sMsgObj[msg_if].DB2R = 0;

  CAN->sMsgObj[msg_if].CRR = 1 + msgobj;
  
  return SUCCESS;
}

/*******************************************************************************
* Function Name  : CAN_SetRxMsgObj                                           
* Description    : Configures the message object as RX.                        
* Input          : - msgobj: specifies the Message object number, from 0 to 31.                    
*                  - idType: specifies the identifier type of the frames that
*                    will be transmitted using this message object.
*                    This parameter can be one of the following values:
*                          - CAN_STD_ID (standard ID, 11-bit)
*                          - CAN_EXT_ID (extended ID, 29-bit)                               
*                  - idLow: specifies the low part of the identifier range used      
*                    for acceptance filtering.
*                  - idHigh: specifies the high part of the identifier range    
*                    used for acceptance filtering.
*                  - singleOrFifoLast: specifies the end-of-buffer indicator.
*                    This parameter can be one of the following values:
*                          - TRUE: for a single receive object or a FIFO receive
*                            object that is the last one of the FIFO. 
*                          - FALSE: for a FIFO receive object that is not the 
*                            last one. 
* Output         : None                                                      
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: Interface to treat the message
*                         - ERROR: No interface to treat the message
*******************************************************************************/
ErrorStatus CAN_SetRxMsgObj(u32 msgobj, u32 idType, u32 idLow, u32 idHigh, bool singleOrFifoLast)
{
  u32 msg_if=0;

  if ((msg_if = GetFreeIF()) == 2)
  {
    return ERROR;
  }
  
  CAN->sMsgObj[msg_if].CMR = CAN_CMR_WRRD
                           | CAN_CMR_MASK
                           | CAN_CMR_ARB
                           | CAN_CMR_CONTROL
                           | CAN_CMR_DATAA
                           | CAN_CMR_DATAB;

  if (idType == CAN_STD_ID)
  {
    CAN->sMsgObj[msg_if].M1R = 0;
    CAN->sMsgObj[msg_if].M2R = STD_RANGE_ID_MSK(idLow, idHigh);

    CAN->sMsgObj[msg_if].A1R = 0;
    CAN->sMsgObj[msg_if].A2R = CAN_A2R_MSGVAL | STD_RANGE_ID_ARB(idLow, idHigh);
  }
  else
  {
    CAN->sMsgObj[msg_if].M1R = EXT_RANGE_ID_MSK_L(idLow, idHigh);
    CAN->sMsgObj[msg_if].M2R = CAN_M2R_MXTD | EXT_RANGE_ID_MSK_H(idLow, idHigh);

    CAN->sMsgObj[msg_if].A1R = EXT_RANGE_ID_ARB_L(idLow, idHigh);
    CAN->sMsgObj[msg_if].A2R = CAN_A2R_MSGVAL | CAN_A2R_XTD | EXT_RANGE_ID_ARB_H(idLow, idHigh);
  }

  CAN->sMsgObj[msg_if].MCR = CAN_MCR_RXIE | CAN_MCR_UMASK | (singleOrFifoLast ? CAN_MCR_EOB : 0);

  CAN->sMsgObj[msg_if].DA1R = 0;
  CAN->sMsgObj[msg_if].DA2R = 0;
  CAN->sMsgObj[msg_if].DB1R = 0;
  CAN->sMsgObj[msg_if].DB2R = 0;

  CAN->sMsgObj[msg_if].CRR = 1 + msgobj;
  
  return SUCCESS;
}

/*******************************************************************************
* Function Name  : CAN_InvalidateAllMsgObj				      
* Description    : Configures all the message objects as unused.               
* Input          : None                                                      
* Output         : None                                                      
* Return         : None                                                      
*******************************************************************************/
void CAN_InvalidateAllMsgObj(void)
{
  u32 i=0;
  for (i = 0; i < 32; i++)
    CAN_SetUnusedMsgObj(i);
}


/*******************************************************************************
* Function Name  : CAN_ReleaseMessage					      
* Description    : Releases the message object                                
* Input          : - msgobj: specifies the Message object number, from 0 to 31.                     
* Output         : None                                                      
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: Interface to treat the message
*                         - ERROR: No interface to treat the message
*******************************************************************************/
ErrorStatus CAN_ReleaseMessage(u32 msgobj)
{
  u32 msg_if=0;

  if ((msg_if = GetFreeIF()) == 2)
  {
    return ERROR;
  }

  CAN->sMsgObj[msg_if].CMR = CAN_CMR_CLRINTPND | CAN_CMR_TXRQSTNEWDAT;
  CAN->sMsgObj[msg_if].CRR = 1 + msgobj;
  
  return SUCCESS;
}

/*******************************************************************************
* Function Name  : CAN_SendMessage                                           
* Description    : Start transmission of a message                           
* Input          : - msgobj: specifies the Message object number, from 0 to 31.                    
*                : - pCanMsg: pointer to the message structure containing data     
*                    to transmit.
* Output         : None                                                      
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: Transmission OK
*                         - ERROR: No transmission
*******************************************************************************/
ErrorStatus CAN_SendMessage(u32 msgobj, canmsg* pCanMsg)
{
  if (CAN->sMsgObj[0].CRR & CAN_CRR_BUSY)
  {
    return ERROR;                    
  }

  CAN->SR &= ~CAN_SR_TXOK;

  /* read the Arbitration and Message Control*/
  CAN->sMsgObj[0].CMR = CAN_CMR_ARB | CAN_CMR_CONTROL;

  CAN->sMsgObj[0].CRR = 1 + msgobj;

  if (CAN->sMsgObj[0].CRR & CAN_CRR_BUSY)
  {
    return ERROR;                    
  }

  /* update the contents needed for transmission*/
  CAN->sMsgObj[0].CMR = CAN_CMR_WRRD
                      | CAN_CMR_ARB
                      | CAN_CMR_CONTROL
                      | CAN_CMR_DATAA
                      | CAN_CMR_DATAB;

  if ((CAN->sMsgObj[0].A2R & CAN_A2R_XTD) == 0)
  {
    /* standard ID*/
    CAN->sMsgObj[0].A1R = 0;
    CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | STD_FIXED_ID_ARB(pCanMsg->Id);
  }
  else
  {
    /* extended ID*/
    CAN->sMsgObj[0].A1R = EXT_FIXED_ID_ARB_L(pCanMsg->Id);
    CAN->sMsgObj[0].A2R = (CAN->sMsgObj[0].A2R & 0xE000) | EXT_FIXED_ID_ARB_H(pCanMsg->Id);
  }

  CAN->sMsgObj[0].MCR = (CAN->sMsgObj[0].MCR & 0xFEF0) | CAN_MCR_NEWDAT | CAN_MCR_TXRQST | pCanMsg->Dlc;

  CAN->sMsgObj[0].DA1R = ((u16)pCanMsg->Data[1]<<8) | pCanMsg->Data[0];
  CAN->sMsgObj[0].DA2R = ((u16)pCanMsg->Data[3]<<8) | pCanMsg->Data[2];
  CAN->sMsgObj[0].DB1R = ((u16)pCanMsg->Data[5]<<8) | pCanMsg->Data[4];
  CAN->sMsgObj[0].DB2R = ((u16)pCanMsg->Data[7]<<8) | pCanMsg->Data[6];

  CAN->sMsgObj[0].CRR = 1 + msgobj;

  return SUCCESS;
}

/*******************************************************************************
* Function Name  : CAN_ReceiveMessage                                        
* Description    : Gets the message, if received.
* Input          : - msgobj: specifies the Message object number, from 0 to 31.                     
*                  - release: specifies the message release indicator.
*                    This parameter can be one of the following values:
*                          - TRUE: the message object is released when getting  
*                            the data.
*                          - FALSE: the message object is not released.
*                  - pCanMsg: pointer to the message structure where received   
*                    data is copied.
* Output         : None                                                      
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: Reception OK
*                         - ERROR: No message pending
*******************************************************************************/
ErrorStatus CAN_ReceiveMessage(u32 msgobj, bool release, canmsg* pCanMsg)
{
  if (!CAN_IsMessageWaiting(msgobj))
  {
    return ERROR;
  }

  CAN->SR &= ~CAN_SR_RXOK;

  /* read the message contents*/
  CAN->sMsgObj[1].CMR = CAN_CMR_MASK
                      | CAN_CMR_ARB
                      | CAN_CMR_CONTROL
                      | CAN_CMR_CLRINTPND
                      | (release ? CAN_CMR_TXRQSTNEWDAT : 0)
                      | CAN_CMR_DATAA
                      | CAN_CMR_DATAB;

  CAN->sMsgObj[1].CRR = 1 + msgobj;

  if (CAN->sMsgObj[1].CRR & CAN_CRR_BUSY)
  {
    return ERROR;                    
  }
  
  if ((CAN->sMsgObj[1].A2R & CAN_A2R_XTD) == 0)
  {
    /* standard ID*/
    pCanMsg->IdType = CAN_STD_ID;
    pCanMsg->Id = (CAN->sMsgObj[1].A2R >> 2) & 0x07FF;
  }
  else
  {
    /* extended ID*/
    pCanMsg->IdType = CAN_EXT_ID;
    pCanMsg->Id  = ((CAN->sMsgObj[1].A2R >> 2) & 0x07FF); 
    pCanMsg->Id |= ((u32)CAN->sMsgObj[1].A1R << 11);
    pCanMsg->Id |= (((u32)CAN->sMsgObj[1].A2R & 0x0003) << 27);
  }

  pCanMsg->Dlc = CAN->sMsgObj[1].MCR & 0x0F;

  pCanMsg->Data[0] = (u8) CAN->sMsgObj[1].DA1R;
  pCanMsg->Data[1] = (u8)(CAN->sMsgObj[1].DA1R >> 8);
  pCanMsg->Data[2] = (u8) CAN->sMsgObj[1].DA2R;
  pCanMsg->Data[3] = (u8)(CAN->sMsgObj[1].DA2R >> 8);
  pCanMsg->Data[4] = (u8) CAN->sMsgObj[1].DB1R;
  pCanMsg->Data[5] = (u8)(CAN->sMsgObj[1].DB1R >> 8);
  pCanMsg->Data[6] = (u8) CAN->sMsgObj[1].DB2R;
  pCanMsg->Data[7] = (u8)(CAN->sMsgObj[1].DB2R >> 8);

  return SUCCESS;
}

/*******************************************************************************
* Function Name  : CAN_WaitEndOfTx                                           
* Description    : Waits until current transmission is finished.               
* Input          : None                                                      
* Output         : None