can.c

Keil 下编译的基于mcs51单片机的PCA82C250CAN收发器控制的程序源代码。

//
//----------------------------------------------------------------------------
// @Parameters    Number of the message object (1-15)
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************
/*
bit CAN_bNewData(unsigned char ObjNr)
{
  bit bReturn;

  bReturn = 0;
  if((CAN_OBJ[ObjNr-1].MCR1 & 0x03) == 0x02)    // if NEWDAT
  {
    bReturn = 1;
  }
  return(bReturn);
}
*/
/*
//****************************************************************************
// @Function      void CAN_vGetMsgObj(unsigned char ObjNr, unsigned char *BufferPointer)
//
//----------------------------------------------------------------------------
// @Description   This function get the data block of the chosen  message object.
//                                
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    Number of message object to be read (1-15)
// @Parameters    Pointer to a buffer to be filled by this function.
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************/
/*
void CAN_vGetMsgObj(unsigned char ObjNr,unsigned char * BufferPointer)
{
    unsigned char i;    
    for(i = 0; i < (CAN_OBJ[ObjNr-1].MCFG & 0xf0) >> 4; i++)
    {
        * (BufferPointer++)= CAN_OBJ[ObjNr-1].Data[i];//get the data block
    }
    if(ObjNr < 15 || (CAN_OBJ[ObjNr-1].MCR0 & 0x0c) != 0x08)
    {
        CAN_OBJ[ObjNr-1].MCR1 = 0xfd;  // reset NEWDAT
    }

}
*/
//****************************************************************************
// @Function      void CAN_vStoreMsgObj(unsigned char ObjNr,unsigned char *BasePointer)
//
//----------------------------------------------------------------------------
// @Description   This function store the data block of the chosen  message object 
//				  to the buffer specified by BufferPointer and identifier
//                                
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    ObjNr---Number of message object to be read (1-15)
//                BasePointer----base pointer of the data buffer.
//----------------------------------------------------------------------------
// @Date          01-10-30 9:51:13
//
//****************************************************************************/
void CAN_vStoreMsgObj(unsigned char ObjNr,unsigned char * BasePointer)
{
    unsigned char i;    
	unsigned int id;
	id=CAN_OBJ[ObjNr-1].UAR0;         //id's high 8 bit
	id=(id<<8 | CAN_OBJ[ObjNr-1].UAR1)>>5;//change id to int
	//##############################################
	//BasePointer+=((id-1)<<3);            //address the buffer by id
	//##################################################
	BasePointer+=(id<<3);            //address the buffer by id
    for(i = 0; i <8; i++)
    {
        * BasePointer= CAN_OBJ[ObjNr-1].Data[i];//get the data block
		BasePointer++;
    }
    if(ObjNr < 15 || (CAN_OBJ[ObjNr-1].MCR0 & 0x0c) != 0x08)
    {
        CAN_OBJ[ObjNr-1].MCR1 = 0xfd;  // reset NEWDAT
    }

}

//****************************************************************************
// @Function      void CAN_vStoreID(unsigned char ObjNr,unsigned char *BasePointer)
//
//----------------------------------------------------------------------------
// @Description   This function store identifier of the chosen  message object 
//				  to the buffer specified by BufferPointer and identifier
//                                
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    ObjNr---Number of message object to be read (1-15)
//                BasePointer----base pointer of the data buffer.
//----------------------------------------------------------------------------
// @Date          01-10-30 9:51:13
//
//****************************************************************************/
void CAN_vStoreID(unsigned char ObjNr,unsigned char * BasePointer)
{
	unsigned int id;
	id=CAN_OBJ[ObjNr-1].UAR0;         //id's high 8 bit
	id=(id<<8 | CAN_OBJ[ObjNr-1].UAR1)>>5;//change id to int
	if(id<=10)
	{
		BasePointer+=(id-1);
		(*BasePointer)=(unsigned char)id;
	}
}


//////////////////////////////与发送有关函数////////////////////////////////////  
//****************************************************************************
// @Function      bit CAN_bRequestMsgObj(unsigned char ObjNr)
//
//----------------------------------------------------------------------------
// @Description   If a TRANSMIT OBJECT is to be reconfigured it must first be
//                accessed. The access to the transmit object is exclusive.
//                This function checks whether the choosen message object is
//                still executing a transmit request, or if the object can 
//                be accessed exclusively.
//                After the message object is reserved, it can be reconfigured
//                by using the function CAN_vConfigMsgObj or CAN_vLoadData.
//                Both functions enable access to the object for the CAN
//                controller.
//                By calling the function CAN_vTransmit transfering of data
//                is started.
//
//----------------------------------------------------------------------------
// @Returnvalue   0 message object is busy (a transfer is actice), else 1
//
//----------------------------------------------------------------------------
// @Parameters    Number of the message object (1-14)
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************

bit CAN_bRequestMsgObj(unsigned char ObjNr)
{
  bit bReturn;

  bReturn = 0;
  if((CAN_OBJ[ObjNr-1].MCR1 & 0x30) == 0x10)  // if TXRQ==0
  {
    CAN_OBJ[ObjNr-1].MCR1 = 0xfb;  // set CPUUPD 
    bReturn = 1;
  }
  return(bReturn);
}

/*
//****************************************************************************
// @Function      void CAN_vLoadData(unsigned char ObjNr, unsigned char *pubBuffer)
//
//----------------------------------------------------------------------------
// @Description   If a message object has to be loaded with data
//                but not with a new identifier, this function may be used
//                instead of the function CAN_vConfigMsgObj.
//                The message object should be accessed by calling the function
//                CAN_bRequestMsgObj before calling this function. This
//                prevents the CAN controller from working with invalid data.
//
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    Number of the message object to be configured (1-15)
// @Parameters    Pointer on a data buffer
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************
void CAN_vLoadData(unsigned char ObjNr, unsigned char *pubBuffer)
{
    unsigned char i;
    CAN_OBJ[ObjNr-1].MCR1=0xfa;//set CPUUPD and NEWDAT
    for(i=0;i<(CAN_OBJ[ObjNr-1].MCFG & 0xf0)>>4;i++)
    {
        CAN_OBJ[ObjNr-1].Data[i]= * (pubBuffer++);
    }
    CAN_OBJ[ObjNr-1].MCR1 = 0xf7;  // reset CPUUPD    
}
*/

//****************************************************************************
// @Function      void CAN_vConfigMsgObj(unsigned char ObjNr,unsigned int id,unsigned char pubBuffer)
//
//----------------------------------------------------------------------------
// @Description   This function sets up the message objects. This includes
//                the 8 data bytes, the identifier (11- or 29-bit),                 number (0-7 bytes) and the XTD-bit.
//                The message is not sent; for this the function
//                CAN_vTransmit must be called.
//
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    ObjNr---Number of the message object to be configured (1-15)
//                id---identifier;
//				  pubBuffer---Pointer on a message object's data;
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************

void CAN_vConfigMsgObj(unsigned char ObjNr,unsigned int id,unsigned char *pubBuffer)
{
	unsigned char i;
	CAN_OBJ[ObjNr-1].MCR1=0xfa;//set CPUUPD and NEWDAT
	CAN_OBJ[ObjNr-1].MCR0=0x7f;
	///////configure identifier//////////
	id=id<<5;
	CAN_OBJ[ObjNr-1].UAR1=(unsigned char)(id % 256);
	CAN_OBJ[ObjNr-1].UAR0=(unsigned char)(id/256);
	///////load data////////////
	
    for(i=0;i<8;i++)
    {
        CAN_OBJ[ObjNr-1].Data[i]= * pubBuffer;
		pubBuffer++;
	wdt_refresh();
	cs5045=0;
	_nop_();
	_nop_();
	cs5045=1;
	}
    CAN_OBJ[ObjNr-1].MCR1 = 0xf7;  // reset CPUUPD   
	CAN_OBJ[ObjNr-1].MCR0  = 0xbf;
}
//****************************************************************************
// @Function      void CAN_vTransmit(unsigned char ObjNr)
//
//----------------------------------------------------------------------------
// @Description   This function triggers the CAN controller to send the 
//                selected message.
//                If the selected message object is a TRANSMIT OBJECT then 
//                this function triggers the sending of a data frame.
//                If however the selected message object is a RECEIVE OBJECT
//                this function triggers the sending of a remote frame.
//                send a data frame or a romote frame
//----------------------------------------------------------------------------
// @Returnvalue   none
//
//----------------------------------------------------------------------------
// @Parameters    Number of the message object to be sent (1-14)
//
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************
void CAN_vTransmit(unsigned char ObjNr)
{
  CAN_OBJ[ObjNr-1].MCR1 = 0xE7;  // set TXRQ, reset CPUUPD
}

//****************************************************************************
//function:      void error_warn(void);  
//description:   communication show ,if error warn 
//parameter:     none
//return:        none
//****************************************************************************
//void error_warn(void)
//{
//    ;
//}

//////////////////////////信息控制寄存器位操作函数///////////////////////////////
//****************************************************************************
// @Function      bit read_msg_MCR(unsigend char ObjNr,MCR_BIT)
//
//----------------------------------------------------------------------------
// @Description   This function read one bit of the message object's control 
//                 register.
//----------------------------------------------------------------------------
// @Returnvalue   Bit value maybe "1" or "0"
//
//----------------------------------------------------------------------------
// @Parameters    Number of the message object (1-15);
//                Bit location of the message control register; 
//----------------------------------------------------------------------------
// @Date          01-2-24 12:51:13
//
//****************************************************************************
/*
bit read_msg_MCR(ObjNr,MCR_BIT)
        unsigned char ObjNr;
        unsigned char MCR_BIT;
{
    unsigned char MCR_temp;
    bit temp_bit;
    switch(MCR_BIT) 
    {
        case MSGVAL:
            MCR_temp=CAN_OBJ[ObjNr-1].MCR0;        //read MCR0
            if((MCR_temp & 0xc0)==0x80){temp_bit=1;} //if MSGVAL=1 then set temp_bit
            if((MCR_temp & 0xc0)==0x40){temp_bit=0;} //if MSGVAL=0 then clear temp_bit
            break;
        case TXIE:
            MCR_temp=CAN_OBJ[ObjNr-1].MCR0;        //read MCR0
            if((MCR_temp & 0x30)==0x20){temp_bit=1;} //if TXIE=1 then set temp_bit
            if((MCR_temp & 0x30)==0x10){temp_bit=0;} //if TXIE=0 then clear temp_bit
            break;
        case RXIE:
            MCR_temp=CAN_OBJ[ObjNr-1].MCR0;        //read MCR0
            if((MCR_temp & 0x0c)==0x08){temp_bit=1;} //if RXIE=1 then set temp_bit
            if((MCR_temp & 0x0c)==0x04){temp_bit=0;} //if RXIE=0 then clear temp_bit
            break;
        case INTPND:
            MCR_temp=CAN_OBJ[ObjNr-1].MCR0;        //read MCR0