本文从理论上推导出CRC 算法实现原理，给出三种分别适应不同计算机或微控

制器硬件环境的C 语言程序。读者更能根据本算法原理，用不同的语言编写出独特风格

更加实用的CRC 计算程序。-This paper theoretically deduced from the principles of CRC algorithm is given three separate computers or micro-controller to adapt to different hardware environment of the C language program. According to this algorithm the reader a better theory, in different languages a unique style of the CRC calculation program more practical.