通信协议 CRC校验和计算方法

 

 public static uint CalCrc16(byte[] buf, int start, int end)
        {
            byte CRC16Lo, CRC16Hi;   //CRC寄存器
            byte CL, CH;             //多项式码&HA001
            byte SaveLo, SaveHi;
            int i, Flag;

            CRC16Hi = 0xFF;
            CRC16Lo = 0xFF;

            CL = 0x1;
            CH = 0xA0;
            for (i = start; i <= end; i++)
            {
                CRC16Lo = (byte)(CRC16Lo ^ buf[i]); //每一个数据与CRC寄存器进行异或

                for (Flag = 0; Flag <= 7; Flag++)
                {
                    SaveHi = CRC16Hi;
                    SaveLo = CRC16Lo;
                    CRC16Hi = (byte)(CRC16Hi / 2);             //高位右移一位
                    CRC16Lo = (byte)(CRC16Lo / 2);             //低位右移一位

                    if ((SaveHi & 0x1) == 0x1)
                    {
                        CRC16Lo = (byte)(CRC16Lo | 0x80);
                    }

                    if ((SaveLo & 0x1) == 0x1)
                    {
                        CRC16Hi = (byte)(CRC16Hi ^ CH);
                        CRC16Lo = (byte)(CRC16Lo ^ CL);
                    }
                }
            }

            return (uint)CRC16Hi * 256 + CRC16Lo;
        }