串口CRC校验程序

1万 · 2019-6-23 16:53

大神帮我看看这个串口CRC校验程序怎么理解，CRC算法跟网上的一样的crc16吧
//the following is MCU code for CRC16 ,please refer.
//-------------------------------------------------------------------------------------------
#define RxCountMax 18
unsigned short RxBuf[RxCountMax];
unsigned short TxBuf[10];
unsigned short RxCnt;
unsigned short TxCnt;
unsigned short Rx50msCnt;
unsigned long pAddr1,pAddr2,pAddr3,pAddr4;

//Receive interrupt routine
void voRxIsr(void)
{
      unsigned short i,CRC_RX,CRC_Tmp;
      RxBuf[RxCnt] = Rx.data;                               //acquire data
      RxCnt++;

      if(RxCnt == RxCountMax) {
            CRC_Tmp =  CRC_CHECK(RxBuf,16);       //CRC Calculation
            CRC_RX = ((unsigned short)RxBuf[RxCountMax-1]<<8) + RxBuf[RxCountMax-2];
            if(CRC_Tmp == CRC_RX){
                     pAddr1 = ((ULONG)(RxBuf[0x3])<<24)|((ULONG)(RxBuf[0x2])<<16)|((ULONG)(RxBuf[0x1])<<8)|RxBuf[0x0];
                     pAddr2 = ((ULONG)(RxBuf[0x7])<<24)|((ULONG)(RxBuf[0x6])<<16)|((ULONG)(RxBuf[0x5])<<8)|RxBuf[0x4];
                     pAddr3 = ((ULONG)(RxBuf[0xB])<<24)|((ULONG)(RxBuf[0xA])<<16)|((ULONG)(RxBuf[0x9])<<8)|RxBuf[0x8];
                     pAddr4 = ((ULONG)(RxBuf[0xF])<<24)|((ULONG)(RxBuf[0xE])<<16)|((ULONG)(RxBuf[0xD])<<8)|RxBuf[0xC];
            }
            RxCnt = 0;
      }
      Rx50msCnt = 0;
      //to add--Clear Receive Data Register Fll flag;
}
//-------------------------------------------------------------------------------------------
//Transfer interrupt routine
void voTxIsr(void)
{
   if(TxCnt <= 9){
            Tx.Register = TxBuf[TxCnt];
            //Clear Tx interrupt flag
            TxCnt++;
            if(TxCnt >= 10){
                     //send interrupt disable
            }
   }
}
//-------------------------------------------------------------------------------------------
//Monitor routine Execute every T Period time
void voMonitor(void)
{
      unsigned short ChxData[4],CRC_Tmp,i;
      Rx50msCnt++;
      if(Rx50msCnt >=500) {
            RxCnt = 0;
            Rx50msCnt = 0;
      }

      ChxData[0].sw = *(unsigned short *)pAddr1;
      ChxData[1].sw = *(unsigned short *)pAddr2;
      ChxData[2].sw = *(unsigned short *)pAddr3;
      ChxData[3].sw = *(unsigned short *)pAddr4;

      for(i=0;i<4;i++){
            TxBuf[2*i+0] = ChxData[i].sb.low;       // ch[i] low byte
            TxBuf[2*i+1] = ChxData[i].sb.hi;       // ch[i] hi byte
      }

      CRC_Tmp = CRC_CHECK(TxBuf,8);
      TxBuf[8] = CRC_Tmp&0xff;
      TxBuf[9] = CRC_Tmp>>8;

      //send first data
      Tx.Register = TxBuf[0];                      //send begin
      //Enalbe TXD interrupt
      TxCnt = 1;
}