#include "csw_crc.h"
/**第三方校验工具
* http://www.ip33.com/crc.html
*/
uint8_t csw_crc8(uint8_t *pbuf, uint16_t len)
{
uint8_t crc = 0x00; //初始值
uint8_t crc_poly = 0x07;
while (len--)
{
crc ^= *pbuf;
for (uint8_t i = 0; i < 8; i++)
{
if (crc & 0x80) //判断最高位为1?
{
crc = (crc << 1) ^ crc_poly;
}
else //最高位为0
{
crc = crc << 1;
}
}
pbuf++;
}
return crc ^0x00;
}
uint16_t csw_crc16(uint8_t *pbuf, uint16_t len)
{
uint16_t crc = 0xFFFF;
while(len--)
{
crc ^= *pbuf;
for (uint8_t i = 0; i < 8; i++)
{
if (crc & 1)
{
crc >>= 1;
crc ^= 0xA001;
}
else
crc >>= 1;
}
pbuf++;
}
return (crc);
}
uint32_t csw_crc32(uint8_t *pbuf, uint32_t len)
{
uint32_t crc, mask;
crc = 0xFFFFFFFF;
while(len--)
{
crc = crc ^ (uint32_t)(*pbuf);
for (uint8_t j = 0; j < 8; j++)
{
mask = -(crc & 1);
crc = (crc >> 1) ^ (0xEDB88320 & mask);
}
pbuf++;
}
return ~crc;
}
