crc5.c

CRC5循环校验法代码生成

unsigned char crc5_epc(unsigned char *ptr,unsigned char len)
{
	unsigned char i,j,k;
	unsigned char crc=0x09;

	j=0x80;
	k=0;
	for(i=0;i<len;i++){ 
		if(crc&0x10){
			crc<<=1;
			crc^=0x09;
		}
		else crc<<=1;
		if(*ptr&j) crc^=0x09;
		j>>=1;
		k++;
		if(k==8){
			j=0x80;
			k=0;
			ptr++;
		}
	}
	return(crc&0x1f);
}