crc8校验代码参考:g(x) = x^8 + x^5 + x^4 + 1（正序）

g(x) = x^8 + x^5 + x^4 + 1（正序）查表crc8码
通过计算：运行速度相对慢，占用内存相对小。
通过查表：运行速度相对快，占用内存相对大。
最终方法的使用，酌情考虑。

一、通过计算

1、计算法代码模块

#ifndef CRC_LIB_CRC8_COMPUTE_H
#define CRC_LIB_CRC8_COMPUTE_H

#endif //CRC_LIB_CRC8_COMPUTE_H

// g(x) = x^8 + x^5 + x^4 + 1

#include <stdio.h>

#define uchar unsigned char
uchar crc8, crc, mm;

uchar calcrc_1byte(uchar abyte) {
    uchar i;
    crc = crc ^ abyte;
    for (i = 8; i > 0; --i) {
        if (crc & 0x80) {
            crc = (crc << 1) ^ 0x31;
        } else { crc = (crc << 1); }
    }
    return crc;
}

uchar res(int num, uchar serial_num[8]) {
    uchar i;
    crc = 0;
    for (i = 0; i < num; i++) {
        mm = serial_num[i];
        crc8 = calcrc_1byte(mm);
    }
    printf("0x%02x\n", crc8);
    return crc8;
}

2、计算法的使用

#include <stdio.h>
#include "crc8_compute.h"

int main() {
    //region g(x) = x^8 + x^5 + x^4 + 1（正序）计算crc8码
    char serial_number1[8] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
    printf("计算0x01这个数的校验值:\n");
    res(1, serial_number1);
    printf("计算0x01，0x02这2个数的校验值:\n");
    res(2, serial_number1);
    printf("初始值为0x00，计算0x01到0x07这些数的校验值:\n");
    res(7, serial_number1);
    //endregion
}

计算0x01这个数的校验值:
0x31
计算0x01，0x02这2个数的校验值:
0x96
初始值为0x00，计算0x01到0x07这些数的校验值:
0xaf

Process finished with exit code 0

二、通过查表

1、查表法代码模块

#include<stdio.h>
#include<math.h>

#define uchar unsigned char

#ifndef CRC_LIB_CRC8_TABLE_H
#define CRC_LIB_CRC8_TABLE_H

#endif //CRC_LIB_CRC8_TABLE_H

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

uchar crc8_table(uchar *p, uchar len) {
    uchar crc = 0x00;
    uchar i;
    for (int i = 0; i < len; i++) {
        crc = tab[crc ^ *p++];
    }
    printf("0x%02x\n", crc);
    return crc;
}

2、查表法的使用

#include <stdio.h>
#include "crc8_table.h"
int main() {
    // region g(x) = x^8 + x^5 + x^4 + 1（正序）查表crc8码
    char serial_number2[] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
    printf("查询0x01这个数的校验值:\n");
    crc8_table(serial_number2,1);
    printf("查询0x01，0x02这2个数的校验值:\n");
    crc8_table(serial_number2,2);
    printf("初始值为0x00，查询0x01到0x07这些数的校验值:\n");
    crc8_table(serial_number2,7);
    // endregion
}

查询0x01这个数的校验值:
0x31
查询0x01，0x02这2个数的校验值:
0x96
初始值为0x00，查询0x01到0x07这些数的校验值:
0xaf

Process finished with exit code 0