CAN通讯收发程序

{

CAN0CTL0 = 0x01; /* Enter Initialization Mode */

while (! (CAN0CTL1&0x01));

// Set the baudrate 20Kbps

CAN0CTL1 = 0x84; //wake up enabled

CAN0BTR0= 0x4F; // SJW =1 .

CAN0BTR1= 0xDF; // Sample 3 times to ensure the correcty.

CAN0IDAC = 0x10;

CAN0IDAR0 = ACC_CODE_ID_JIAOXIANG_HIGH ;

CAN0IDMR0 = MASK_CODE_ST_ID_HIGH;

CAN0IDAR1 = ACC_CODE_ID_JIAOXIANG_LOW;

CAN0IDMR1 = MASK_CODE_ST_ID_LOW;

CAN0IDAC = 0x10;

CAN0IDAR2 = 0x00;

CAN0IDMR2 = MASK_CODE_ST_ID_HIGH;

CAN0IDAR3 = 0x00;

CAN0IDMR3 = MASK_CODE_ST_ID_LOW;

CAN0IDAR4 = 0x00;

CAN0IDMR4 = MASK_CODE_ST_ID_HIGH;

CAN0IDAR5 = 0x00;

CAN0IDMR5 = MASK_CODE_ST_ID_LOW;

CAN0IDAR6 = 0x00;

CAN0IDMR6 = MASK_CODE_ST_ID_HIGH;

CAN0IDAR7 = 0x00;

CAN0IDMR7 = MASK_CODE_ST_ID_LOW;

CAN0CTL0 = 0x00; /* Exit Initialization Mode Request */

while ((CAN0CTL1&0x01) != 0) ;

}

void interrupt CAN_RX_ISR(void)

{

uchar length, index;

uchar rxdata[8];

length = (CANRXDLR & 0x0F);

for (index=0; indexrxdata[index] = *(&CANRXDSR0 + index); /* Get received data */

CANRFLG = 0x01; /* Clear RXF */

}

uchar CANSendFrame (unsigned long id, uchar priority, uchar length, uchar *txdata )

{

uchar txbuffer;

if (!CANTFLG) //Is Transmit Buffer full ? Full ( TXEx=0;)

return ERR_BUFFER_FULL;

CANTBSEL = CANTFLG; /* Select lowest empty buffer */

txbuffer = CANTBSEL; // Backup selected buffer

/* Load Id to IDR Register */

*((unsigned long *) ((unsigned long)(&CANTXIDR0))) = id; // I appreciate this , easy and good.

if(length>8)

length=8;

for ( index=0; index*(&CANTXDSR0 + index) = txdata[index]; //Load data to Tx buffer Data Segment Registers

}

CANTXDLR = length; /* Set Data Length Code */

CANTXTBPR = priority; /* Set Priority */

CANTFLG = txbuffer; /* Start transmission */

while ( (CANTFLG & txbuffer) != txbuffer); // Wait for Transmission completion

PTM = 0xFF;

}