与硬件通信 需要进行CRC校验 ,参考博客 https://blog.csdn.net/Backspace110/article/details/84755054
/******************************************************************************
* Name: CRC-4/ITU x4+x+1
* Poly: 0x03
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc4_itu(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x0C;// 0x0C = (reverse 0x03)>>(8-4)
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-5/EPC x5+x3+1
* Poly: 0x09
* Init: 0x09
* Refin: False
* Refout: False
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc5_epc(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0x48; // Initial value: 0x48 = 0x09<<(8-5)
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for ( i = 0; i < 8; i++ )
{
if ( crc & 0x80 )
crc = (crc << 1) ^ 0x48; // 0x48 = 0x09<<(8-5)
else
crc <<= 1;
}
}
return crc >> 3;
}
/******************************************************************************
* Name: CRC-5/ITU x5+x4+x2+1
* Poly: 0x15
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc5_itu(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x15;// 0x15 = (reverse 0x15)>>(8-5)
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-5/USB x5+x2+1
* Poly: 0x05
* Init: 0x1F
* Refin: True
* Refout: True
* Xorout: 0x1F
* Note:
*****************************************************************************/
uint8_t crc5_usb(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0x1F; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x14;// 0x14 = (reverse 0x05)>>(8-5)
else
crc = (crc >> 1);
}
}
return crc ^ 0x1F;
}
/******************************************************************************
* Name: CRC-6/ITU x6+x+1
* Poly: 0x03
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc6_itu(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x30;// 0x30 = (reverse 0x03)>>(8-6)
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-7/MMC x7+x3+1
* Poly: 0x09
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x00
* Use: MultiMediaCard,SD,ect.
*****************************************************************************/
uint8_t crc7_mmc(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for ( i = 0; i < 8; i++ )
{
if ( crc & 0x80 )
crc = (crc << 1) ^ 0x12; // 0x12 = 0x09<<(8-7)
else
crc <<= 1;
}
}
return crc >> 1;
}
/******************************************************************************
* Name: CRC-8 x8+x2+x+1
* Poly: 0x07
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc8(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for ( i = 0; i < 8; i++ )
{
if ( crc & 0x80 )
crc = (crc << 1) ^ 0x07;
else
crc <<= 1;
}
}
return crc;
}
/******************************************************************************
* Name: CRC-8/ITU x8+x2+x+1
* Poly: 0x07
* Init: 0x00
* Refin: False
* Refout: False
* Xorout: 0x55
* Alias: CRC-8/ATM
*****************************************************************************/
uint8_t crc8_itu(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for ( i = 0; i < 8; i++ )
{
if ( crc & 0x80 )
crc = (crc << 1) ^ 0x07;
else
crc <<= 1;
}
}
return crc ^ 0x55;
}
/******************************************************************************
* Name: CRC-8/ROHC x8+x2+x+1
* Poly: 0x07
* Init: 0xFF
* Refin: True
* Refout: True
* Xorout: 0x00
* Note:
*****************************************************************************/
uint8_t crc8_rohc(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0xFF; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xE0; // 0xE0 = reverse 0x07
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-8/MAXIM x8+x5+x4+1
* Poly: 0x31
* Init: 0x00
* Refin: True
* Refout: True
* Xorout: 0x00
* Alias: DOW-CRC,CRC-8/IBUTTON
* Use: Maxim(Dallas)'s some devices,e.g. DS18B20
*****************************************************************************/
uint8_t crc8_maxim(uint8_t *data, uint_len length)
{
uint8_t i;
uint8_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; i++)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x8C; // 0x8C = reverse 0x31
else
crc >>= 1;
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/IBM x16+x15+x2+1
* Poly: 0x8005
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0x0000
* Alias: CRC-16,CRC-16/ARC,CRC-16/LHA
*****************************************************************************/
uint16_t crc16_ibm(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001; // 0xA001 = reverse 0x8005
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/MAXIM x16+x15+x2+1
* Poly: 0x8005
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Note:
*****************************************************************************/
uint16_t crc16_maxim(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001; // 0xA001 = reverse 0x8005
else
crc = (crc >> 1);
}
}
return ~crc; // crc^0xffff
}
/******************************************************************************
* Name: CRC-16/USB x16+x15+x2+1
* Poly: 0x8005
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Note:
*****************************************************************************/
uint16_t crc16_usb(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0xffff; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001; // 0xA001 = reverse 0x8005
else
crc = (crc >> 1);
}
}
return ~crc; // crc^0xffff
}
/******************************************************************************
* Name: CRC-16/MODBUS x16+x15+x2+1
* Poly: 0x8005
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0x0000
* Note:
*****************************************************************************/
uint16_t crc16_modbus(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0xffff; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA001; // 0xA001 = reverse 0x8005
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/CCITT x16+x12+x5+1
* Poly: 0x1021
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0x0000
* Alias: CRC-CCITT,CRC-16/CCITT-TRUE,CRC-16/KERMIT
*****************************************************************************/
uint16_t crc16_ccitt(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x8408; // 0x8408 = reverse 0x1021
else
crc = (crc >> 1);
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/CCITT-FALSE x16+x12+x5+1
* Poly: 0x1021
* Init: 0xFFFF
* Refin: False
* Refout: False
* Xorout: 0x0000
* Note:
*****************************************************************************/
uint16_t crc16_ccitt_false(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0xffff; //Initial value
while(length--)
{
crc ^= (uint16_t)(*data++) << 8; // crc ^= (uint6_t)(*data)<<8; data++;
for (i = 0; i < 8; ++i)
{
if ( crc & 0x8000 )
crc = (crc << 1) ^ 0x1021;
else
crc <<= 1;
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/X25 x16+x12+x5+1
* Poly: 0x1021
* Init: 0xFFFF
* Refin: True
* Refout: True
* Xorout: 0XFFFF
* Note:
*****************************************************************************/
uint16_t crc16_x25(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0xffff; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0x8408; // 0x8408 = reverse 0x1021
else
crc = (crc >> 1);
}
}
return ~crc; // crc^Xorout
}
/******************************************************************************
* Name: CRC-16/XMODEM x16+x12+x5+1
* Poly: 0x1021
* Init: 0x0000
* Refin: False
* Refout: False
* Xorout: 0x0000
* Alias: CRC-16/ZMODEM,CRC-16/ACORN
*****************************************************************************/
uint16_t crc16_xmodem(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0; // Initial value
while(length--)
{
crc ^= (uint16_t)(*data++) << 8; // crc ^= (uint16_t)(*data)<<8; data++;
for (i = 0; i < 8; ++i)
{
if ( crc & 0x8000 )
crc = (crc << 1) ^ 0x1021;
else
crc <<= 1;
}
}
return crc;
}
/******************************************************************************
* Name: CRC-16/DNP x16+x13+x12+x11+x10+x8+x6+x5+x2+1
* Poly: 0x3D65
* Init: 0x0000
* Refin: True
* Refout: True
* Xorout: 0xFFFF
* Use: M-Bus,ect.
*****************************************************************************/
uint16_t crc16_dnp(uint8_t *data, uint_len length)
{
uint8_t i;
uint16_t crc = 0; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xA6BC; // 0xA6BC = reverse 0x3D65
else
crc = (crc >> 1);
}
}
return ~crc; // crc^Xorout
}
/******************************************************************************
* Name: CRC-32 x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
* Poly: 0x4C11DB7
* Init: 0xFFFFFFF
* Refin: True
* Refout: True
* Xorout: 0xFFFFFFF
* Alias: CRC_32/ADCCP
* Use: WinRAR,ect.
*****************************************************************************/
uint32_t crc32(uint8_t *data, uint_len length)
{
uint8_t i;
uint32_t crc = 0xffffffff; // Initial value
while(length--)
{
crc ^= *data++; // crc ^= *data; data++;
for (i = 0; i < 8; ++i)
{
if (crc & 1)
crc = (crc >> 1) ^ 0xEDB88320;// 0xEDB88320= reverse 0x04C11DB7
else
crc = (crc >> 1);
}
}
return ~crc;
}
/******************************************************************************
* Name: CRC-32/MPEG-2 x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
* Poly: 0x4C11DB7
* Init: 0xFFFFFFF
* Refin: False
* Refout: False
* Xorout: 0x0000000
* Note:
*****************************************************************************/
uint32_t crc32_mpeg_2(uint8_t *data, uint_len length)
{
uint8_t i;
uint32_t crc = 0xffffffff; // Initial value
while(length--)
{
crc ^= (uint32_t)(*data++) << 24;// crc ^=(uint32_t)(*data)<<24; data++;
for (i = 0; i < 8; ++i)
{
if ( crc & 0x80000000 )
crc = (crc << 1) ^ 0x04C11DB7;
else
crc <<= 1;
}
}
return crc;
}
使用方法:
首先,根据输入数据长度定义合适的uint_len类型,因为是逐位运算,所以不推荐用在实时性较高的情况下,而且数据也不易过长,大多数嵌入书的开发过程中需要校验的寄存器数据也不会太对
这里使用:
typedef uint16_t uint_len
//自己写个主函数 定义一组测试数据:
int main()
{
uint8_t serno[0x91,0xA3,0xB5,0xC7,0x8D,0xEB,0x2D,0x4E];
//输出测试数据的CRC32 检验码
printf("%x\n",crc32(serno,sizeof(serno)));
//输出测试数据的CRC8校验和
printf("%x\n",crc8(serno,sixeof(serno)));
//.....
return 0;
}
有几个crc函数([b]注意!并是不所有的[/b])可以把校验码直接放在数据流后面一同输入,如果返回值为0,则校验通过
比如上面的serno的crc8校验码是 0X23
令
uint8_t serno2[] = { 0x91, 0xA3, 0xB5, 0xC7, 0x8D, 0xEB, 0x2D, 0x4E,[b] 0x23 [/b]};
则执行printf("%x\n",crc8(serno2, sizeof(serno2)));
得到的输出即为0.
有的函数不为0的原因是最后一步进行了异或操作(return crc^Xorout)
其实crc校验都是一个套路,在写crc8的时候,写着写着就把所有的都写出来了.
crc64其实根据crc32也能很简单的写出来,用的不多,就不写了.