HS550/ECU_APP/user/CRC.c

#include "crc.h"
//#include <stdio.h> //用于验证和生成CRC_Table

static const unsigned char crc_table[] =
{
0x00, 0x1d, 0x3a, 0x27, 0x74, 0x69, 0x4e, 0x53, 0xe8, 0xf5, 0xd2, 0xcf, 0x9c, 0x81, 0xa6, 0xbb,
0xcd, 0xd0, 0xf7, 0xea, 0xb9, 0xa4, 0x83, 0x9e, 0x25, 0x38, 0x1f, 0x02, 0x51, 0x4c, 0x6b, 0x76,
0x87, 0x9a, 0xbd, 0xa0, 0xf3, 0xee, 0xc9, 0xd4, 0x6f, 0x72, 0x55, 0x48, 0x1b, 0x06, 0x21, 0x3c,
0x4a, 0x57, 0x70, 0x6d, 0x3e, 0x23, 0x04, 0x19, 0xa2, 0xbf, 0x98, 0x85, 0xd6, 0xcb, 0xec, 0xf1,
0x13, 0x0e, 0x29, 0x34, 0x67, 0x7a, 0x5d, 0x40, 0xfb, 0xe6, 0xc1, 0xdc, 0x8f, 0x92, 0xb5, 0xa8,
0xde, 0xc3, 0xe4, 0xf9, 0xaa, 0xb7, 0x90, 0x8d, 0x36, 0x2b, 0x0c, 0x11, 0x42, 0x5f, 0x78, 0x65,
0x94, 0x89, 0xae, 0xb3, 0xe0, 0xfd, 0xda, 0xc7, 0x7c, 0x61, 0x46, 0x5b, 0x08, 0x15, 0x32, 0x2f,
0x59, 0x44, 0x63, 0x7e, 0x2d, 0x30, 0x17, 0x0a, 0xb1, 0xac, 0x8b, 0x96, 0xc5, 0xd8, 0xff, 0xe2,
0x26, 0x3b, 0x1c, 0x01, 0x52, 0x4f, 0x68, 0x75, 0xce, 0xd3, 0xf4, 0xe9, 0xba, 0xa7, 0x80, 0x9d,
0xeb, 0xf6, 0xd1, 0xcc, 0x9f, 0x82, 0xa5, 0xb8, 0x03, 0x1e, 0x39, 0x24, 0x77, 0x6a, 0x4d, 0x50,
0xa1, 0xbc, 0x9b, 0x86, 0xd5, 0xc8, 0xef, 0xf2, 0x49, 0x54, 0x73, 0x6e, 0x3d, 0x20, 0x07, 0x1a,
0x6c, 0x71, 0x56, 0x4b, 0x18, 0x05, 0x22, 0x3f, 0x84, 0x99, 0xbe, 0xa3, 0xf0, 0xed, 0xca, 0xd7,
0x35, 0x28, 0x0f, 0x12, 0x41, 0x5c, 0x7b, 0x66, 0xdd, 0xc0, 0xe7, 0xfa, 0xa9, 0xb4, 0x93, 0x8e,
0xf8, 0xe5, 0xc2, 0xdf, 0x8c, 0x91, 0xb6, 0xab, 0x10, 0x0d, 0x2a, 0x37, 0x64, 0x79, 0x5e, 0x43,
0xb2, 0xaf, 0x88, 0x95, 0xc6, 0xdb, 0xfc, 0xe1, 0x5a, 0x47, 0x60, 0x7d, 0x2e, 0x33, 0x14, 0x09,
0x7f, 0x62, 0x45, 0x58, 0x0b, 0x16, 0x31, 0x2c, 0x97, 0x8a, 0xad, 0xb0, 0xe3, 0xfe, 0xd9, 0xc4
};

unsigned char CRC_Calc(unsigned char * dataptr,unsigned char len)
{
    unsigned char i; 
    unsigned char crc=0xFF; // 计算的初始crc值   

    while(len--)
    {
        crc ^= *dataptr++;  // 每次先与需要计算的数据异或,计算完指向下一数据    
        for (i=0; i<8; i++)   // 下面这段计算过程与计算一个字节crc一样    
        { 
            if (crc & 0x80)	// 判断最高位是否为1  
            // 最高位为1，不需要异或，往左移一位，然后与0x31异或  
			// 0x31(多项式：x8+x5+x4+1，100110001)，最高位不需要异或，直接去掉  
                crc = (crc << 1) ^ 0x1D;
            else
                crc = (crc << 1);
        }
    }

    return (crc^0XFF); 
}


unsigned char CRC_Calc_Table(unsigned char * dataptr,unsigned char len)
{
    unsigned char  crc = 0xFF;

    while (len--)
    {
        crc = crc_table[crc ^ *dataptr++];
    }
    return (crc^0XFF);
}


//以下程序用于验证和生成CRC_Table
/*
unsigned char cal_table_high_first(unsigned char value)
{
    unsigned char i, crc;

    crc = value;
    //数据往左移了8位，需要计算8次
    for (i=0; i<8; i++)
    { 
        if (crc & 0x80)  //判断最高位是否为1
        {
        //最高位为1，不需要异或，往左移一位，然后与0x31异或  
        //0x31(多项式：x8+x5+x4+1，100110001)，最高位不需要异或，直接去掉  
            crc = (crc << 1) ^ 0x1D;        }
        else
        {
            //最高位为0时，不需要异或，整体数据往左移一位  
            crc = (crc << 1);
        }
    }

    return crc;
}

//计算crc_Table 
void  create_crc_table(void)
{
    unsigned short i;
    unsigned char j;

    for (i=0; i<=0xFF; i++)
    {
        if (0 == (i%16))
            printf("\n");

        j = i&0xFF;
        printf("0x%.2x, ", cal_table_high_first (j));  //依次计算每个字节的crc校验值 
    }
}


int main()
{
    unsigned char TestArr[] = {0x00,0x15,0x22,0x11,0xff,0x13,0x66};
    unsigned char crc;
    printf("crc_data = {0x00,0x15,0x22,0x11,0xff,0x13,0x66}\n");
    crc = CRC_Calc(TestArr,7);
    printf("CRC_Calc       = 0x%x \n",crc);
    crc = CRC_Calc_Table(TestArr,7);
	printf("CRC_Calc_Table = 0x%x \n",crc);
    return 0;
}
*/