crc16 keil c51

cpubbs

#pragma small
#include <reg52.h>
unsigned int CRC_16(unsigned int c,unsigned char d);
unsigned int    crc16=0;

void main(void)
{
//  unsigned char crcbuff[] = {31,3,0,1,0,7};
   unsigned char crcbuff[] = "123456789";
    unsigned char *p;
//  unsigned int crc16 = 0xffff;
    p=crcbuff;
while(*p !='\0')
    {
        crc16 = CRC_16(crc16,*p++);
    }
p=crcbuff;
}

unsigned int CRC_16(unsigned int c,unsigned char d)
{
    unsigned int data e;
    unsigned char data f;
    e = c^(unsigned int)d;
    for(f=0;f<8;f++)
    {
        if(e&1)
        {
            e >>= 1;
            e ^= 0xa001;
        }
        else e >>= 1;
    }
    return e;
}
// 使用字符串"123456789"测试,crc16初始值为0时
// 结果为0xbb3d 符合crc caculator