CRC16 Calculation

crc.c

unsigned short crc_16_rec(unsigned char * pucData, unsigned short ucLen) {
  //--------------------------------------------------------------------
  unsigned int i;
  unsigned char ucBit, ucCarry;
  //--------------------------------------------------------------------
  unsigned short usPoly = 0x8408; //reversed 0x1021
  unsigned short usCRC = 0;
  //--------------------------------------------------------------------
  for (i = 0; i < ucLen; i++) {
    usCRC ^= pucData[i];
    for (ucBit = 0; ucBit < 8; ucBit++) {
      ucCarry = usCRC & 1;
      usCRC >>= 1;
      if (ucCarry) {
        usCRC ^= usPoly;
      }
    }
  }
  return usCRC;
}