针对模拟SDIO中的CRC算法优化

zr***

使用GPIO模拟SDIO时要使用软件计算crc，这里使用查表法针对crc7，单线crc16进行优化。
/*----------------------------------------------------*/
unsigned char crc7_table[256]={
    0x00,0x12,0x24,0x36,0x48,0x5a,0x6c,0x7e,
    0x90,0x82,0xb4,0xa6,0xd8,0xca,0xfc,0xee,
    0x32,0x20,0x16,0x04,0x7a,0x68,0x5e,0x4c,
    0xa2,0xb0,0x86,0x94,0xea,0xf8,0xce,0xdc,
    0x64,0x76,0x40,0x52,0x2c,0x3e,0x08,0x1a,
    0xf4,0xe6,0xd0,0xc2,0xbc,0xae,0x98,0x8a,
    0x56,0x44,0x72,0x60,0x1e,0x0c,0x3a,0x28,
    0xc6,0xd4,0xe2,0xf0,0x8e,0x9c,0xaa,0xb8,
    0xc8,0xda,0xec,0xfe,0x80,0x92,0xa4,0xb6,
    0x58,0x4a,0x7c,0x6e,0x10,0x02,0x34,0x26,
    0xfa,0xe8,0xde,0xcc,0xb2,0xa0,0x96,0x84,
    0x6a,0x78,0x4e,0x5c,0x22,0x30,0x06,0x14,
    0xac,0xbe,0x88,0x9a,0xe4,0xf6,0xc0,0xd2,
    0x3c,0x2e,0x18,0x0a,0x74,0x66,0x50,0x42,
    0x9e,0x8c,0xba,0xa8,0xd6,0xc4,0xf2,0xe0,
    0x0e,0x1c,0x2a,0x38,0x46,0x54,0x62,0x70,
    0x82,0x90,0xa6,0xb4,0xca,0xd8,0xee,0xfc,
    0x12,0x00,0x36,0x24,0x5a,0x48,0x7e,0x6c,
    0xb0,0xa2,0x94,0x86,0xf8,0xea,0xdc,0xce,
    0x20,0x32,0x04,0x16,0x68,0x7a,0x4c,0x5e,
    0xe6,0xf4,0xc2,0xd0,0xae,0xbc,0x8a,0x98,
    0x76,0x64,0x52,0x40,0x3e,0x2c,0x1a,0x08,
    0xd4,0xc6,0xf0,0xe2,0x9c,0x8e,0xb8,0xaa,
    0x44,0x56,0x60,0x72,0x0c,0x1e,0x28,0x3a,
    0x4a,0x58,0x6e,0x7c,0x02,0x10,0x26,0x34,
    0xda,0xc8,0xfe,0xec,0x92,0x80,0xb6,0xa4,
    0x78,0x6a,0x5c,0x4e,0x30,0x22,0x14,0x06,
    0xe8,0xfa,0xcc,0xde,0xa0,0xb2,0x84,0x96,
    0x2e,0x3c,0x0a,0x18,0x66,0x74,0x42,0x50,
    0xbe,0xac,0x9a,0x88,0xf6,0xe4,0xd2,0xc0,
    0x1c,0x0e,0x38,0x2a,0x54,0x46,0x70,0x62,
    0x8c,0x9e,0xa8,0xba,0xc4,0xd6,0xe0,0xf2,
};

unsigned char crc7_mmc(unsigned char *dat,unsigned int length)
{
    unsigned char crc=0x00;
    while(length--){
        crc=crc7_table[crc^*dat++];   
    }
    return crc|0x01;
}

/*----------------------------------------------------*/




unsigned int crc16_table[256] = {
    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
    0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
    0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
    0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
    0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
    0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
    0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
    0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
    0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
    0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
    0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
    0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
    0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
    0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
    0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
    0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
    0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
    0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
    0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
    0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
    0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
    0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
    0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
    0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
    0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
    0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
    0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
    0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
    0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
    0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
    0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
    0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
//单线下的CRC16
unsigned short crc16_xmodem(unsigned char *dat,int len)
{
    unsigned short crc = 0x0000;
   
    while(len--)
    {
        crc = (crc << 8) ^ crc16_table[(crc >> 8 ^ *dat++) & 0xff];
    }
   
    return(crc);
}

zr***

4线crc，一次可以计算两个字节，且不用查表
void fourlinecrc(unsigned char *dat,unsigned long *crc,int len)
{
        unsigned long temp,temp1;
        crc[0]=0;
        crc[1]=0;
        while(len){
                len-=2;
                temp1=(crc[0]>>16)^(((unsigned short)(*dat<<8))|(unsigned short)(*(dat+1)));
                temp=(crc[1]>>16);
                crc[0]<<=16;
                crc[0]|=temp;
                crc[1]<<=16;
                crc[0]^=temp1<<16|temp1>>12;
                crc[1]^=temp1<<20|temp1;
                dat+=2;
        }
//按QSPI的方式将crc[0],crc[1]发送即可
}

wlh***

最大速度能达到多少，用的什么mcu

zr***

wlh*** 发表于 2025-1-27 07:58
最大速度能达到多少，用的什么mcu

只在电脑上验证了算法的可行性，没测试

zr***

四线crc-16,一次计算一个字节
void fourlinecrc(unsigned char *dat,unsigned long *crc,int len)
{
        unsigned long temp,temp1;
        crc[0]=0;
        crc[1]=0;
        while(len--){
                temp1=(crc[0]>>24)^(*dat);
                temp=(crc[1]>>24);
                crc[0]<<=8;
                crc[0]|=temp;
                crc[1]<<=8;
                crc[0]^=temp1<<16;
                crc[1]^=temp1<<20|temp1;
                dat++;
        }
//按QSPI的方式将crc[0],crc[1]发送即可
}