报文解析及CRC类

    /// <summary>
    /// 报文解析转换类
    /// </summary>
    public class DatagramConvert
    {
        public static Encoding ENCODING_ASCII = Encoding.ASCII;
        public static Encoding ENCODING_GB2312 = Encoding.GetEncoding("gb2312");
        public static Crc16Ccitt CRC16 = new Crc16Ccitt(InitialCrcValue.NonZero1);

        #region 数据转换、解析相关方法
        /// <summary>
        /// 解析报文信息,返回完整的报文内容列表
        /// </summary>
        /// <param name="datagram"></param>
        /// <param name="startTag"></param>
        /// <returns></returns>
        public static List<string> DatagramParser(ref string datagram, string startTag = "FAF5")
        {
            List<string> list = new List<string>();
            if (string.IsNullOrWhiteSpace(datagram))
            {
                return list;
            }
            int index;
            while ((index = datagram.IndexOf(startTag)) > -1)
            {
                if (datagram.Length <= index + 6) // 判断是否包含长度信息
                {
                    break;
                }
                int len = Convert.ToInt32(datagram.Substring(index + 4, 2), 16) * 2; // 获取数据包长度
                if (datagram.Length < index + len + 10) // 判断是否包含完整的报文
                {
                    break;
                }
                string newDatagram = datagram.Substring(index, len + 10); // 获取完整的报文
                list.Add(newDatagram);
                datagram = datagram.Substring(index + len + 10); // 获取余下的报文信息
            }

            return list;
        }

        /// <summary>
        /// 拆分数据
        /// </summary>
        /// <param name="msgs">2位长度的hex字符串数组</param>
        /// <param name="start">开始索引</param>
        /// <param name="end">截止位置</param>
        /// <param name="msgtype"></param>
        /// <returns></returns>
        public static object GetString(string[] msgs, int start, int end, string msgtype)
        {
            List<byte> msgarry = new List<byte>();
            string msg = "0x";
            for (int i = start; i <= end; i++)
            {
                if (msgtype == "string")
                {
                    msgarry.Add((byte)Convert.ToInt32(msgs[i], 16));
                }
                else
                {
                    msg += msgs[i];
                }
            }
            if (msgtype == "string")
            {
                return msgarry;
            }
            else
            {
                return msg;
            }
        }

        /// <summary>
        /// 向集合中添加批量添加元素
        /// </summary>
        /// <param name="bitarry"></param>
        /// <param name="list"></param>
        public static void AddRange(string[] bitarry, ref  List<string> list)
        {
            for (int i = 0; i < bitarry.Length; i++)
            {
                list.Add(bitarry[i]);
            }
        }

        /// <summary>
        /// 从字节数组中提取固定长度的元素,提取个数超出数组大小时填充(byte)0
        /// </summary>
        /// <param name="bts">字节数组</param>
        /// <param name="count">提取长度</param>
        /// <returns></returns>
        public static byte[] BytesExtract(byte[] bts, int count)
        {
            byte[] returnBytes = new byte[count];
            for (int i = 0; i < bts.Length && i < count; i++)
            {
                returnBytes[i] = bts[i];
            }
            if (bts.Length < count)
            {
                for (int i = bts.Length; i < count; i++)
                {
                    returnBytes[i] = Convert.ToByte(0);
                }
            }
            return returnBytes;
        }

        /// <summary>
        /// 将字节数组转换为制定长度的16位字符串数组
        /// </summary>
        /// <param name="bts">字节数组</param>
        /// <param name="count">返回字符串长度</param>
        /// <returns></returns>
        public static string[] BytesToHexArray(byte[] bts, int count)
        {
            string[] returnBytes = new string[count];
            for (int i = 0; i < bts.Length; i++)
            {
                returnBytes[i] = Convert10To16(bts[i]).ToUpper();
            }
            if (bts.Length < count)
            {
                for (int i = bts.Length; i < count; i++)
                {
                    returnBytes[i] = "00";
                }
            }
            return returnBytes;
        }

        /// <summary>
        /// 16进制字符串按2个长度分割成字节数组
        /// </summary>
        /// <param name="hexString"></param>
        /// <returns></returns>
        public static byte[] HexStringToBytes(string hexString)
        {
            hexString = hexString.Replace(" ", "");
            if ((hexString.Length % 2) != 0)
                hexString += " ";
            byte[] returnBytes = new byte[hexString.Length / 2];
            for (int i = 0; i < returnBytes.Length; i++)
                returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
            return returnBytes;
        }

        /// <summary>
        /// 将16进制字符串按2个长度进行分割
        /// </summary>
        /// <param name="hexString">16进制字符串</param>
        /// <returns></returns>
        public static string[] HexStringToArray(string hexString)
        {
            hexString = hexString.Replace(" ", "");
            if ((hexString.Length % 2) != 0)
                hexString += " ";
            string[] returnBytes = new string[hexString.Length / 2];
            for (int i = 0; i < returnBytes.Length; i++)
                returnBytes[i] = hexString.Substring(i * 2, 2);
            return returnBytes;
        }

        /// <summary>
        /// 十进制转十六进制
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string Convert10To16(int value)
        {
            return Convert.ToString(value, 16);
        }

        /// <summary>
        /// 十进制转十六进制
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string Convert10To16(long value)
        {
            return Convert.ToString(value, 16);
        }

        /// <summary>
        /// 十进制转十六进制
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static int Convert10To16(string value)
        {
            return Convert.ToInt32(value, 16);
        }

        /// <summary>
        /// 十进制转十六进制
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static int Convert16To10(string value)
        {
            return Convert.ToInt32(value, 16);
        }

        /// <summary>
        /// 数据类型转换示例
        /// </summary>
        private static void DataConvertDemo()
        {
            //十进制转二进制 

            Console.WriteLine(Convert.ToString(69, 2));

            //十进制转八进制 

            Console.WriteLine(Convert.ToString(69, 8));

            //十进制转十六进制 

            Console.WriteLine(Convert.ToString(69, 16));

            //二进制转十进制 

            Console.WriteLine(Convert.ToInt32("100111101", 2));

            //八进制转十进制 

            Console.WriteLine(Convert.ToInt32("76", 8));

            //C# 16进制转换10进制 

            Console.WriteLine(Convert.ToInt32("FF", 16));

        }

        /// <summary>
        /// CRC异或校验
        /// </summary>
        /// <param name="cmdString">命令字符串</param>
        /// <returns></returns>
        public static string CRC(string cmdString)
        {
            try
            {
                //CRC寄存器
                int CRCCode = 0;
                // 将字符串拆分成为16进制字节数据然后两位两位进行异或校验
                for (int i = 1; i < cmdString.Length / 2; i++)
                {
                    string cmdHex = cmdString.Substring(i * 2, 2);
                    if (i == 1)
                    {
                        string cmdPrvHex = cmdString.Substring((i - 1) * 2, 2);
                        CRCCode = (byte)Convert.ToInt32(cmdPrvHex, 16) ^ (byte)Convert.ToInt32(cmdHex, 16);
                    }
                    else
                    {
                        CRCCode = (byte)CRCCode ^ (byte)Convert.ToInt32(cmdHex, 16);
                    }
                }
                return CRCCode.ToString("X2");// 返回16进制校验码
            }
            catch
            {
                return "00";
            }
        }
        #endregion
    }

CRC-16-CCITT效验类

    /// <summary>   
    /// 循环冗余检验：CRC-16-CCITT查表法   
    /// </summary>   
    public static class CRCITU16
    {
        /// <summary>   
        /// 计算给定长度数据的16位CRC   
        /// </summary>   
        /// <param name="data">要计算CRC的字节数组</param>   
        /// <returns>CRC值</returns>   
        public static UInt16 GetCrc16(Byte[] data)
        {   // 初始化   
            Int32 High = 0xFF;  // 高字节   
            Int32 Low = 0xFF;   // 低字节   
            if (data != null)
            {
                foreach (Byte b in data)
                {
                    Int32 Index = Low ^ b;
                    Low = High ^ CRC16TABLE_LO[Index];
                    High = CRC16TABLE_HI[Index];
                }
            }

            return (UInt16)(~((High << 8) + Low));    // 取反   
        }

        /// <summary>   
        /// 检查给定长度数据的16位CRC是否正确   
        /// </summary>   
        /// <param name="data">要校验的字节数组</param>   
        /// <returns>   
        ///     true：正确   
        ///     false：错误   
        /// </returns>   
        /// <reamrks>   
        /// 字节数组最后2个字节为校验码，且低字节在前面，高字节在后面   
        /// </reamrks>   
        public static Boolean IsCrc16Good(Byte[] data)
        {
            // 初始化   
            Int32 High = 0xFF;
            Int32 Low = 0xFF;
            if (data != null)
            {
                foreach (Byte b in data)
                {
                    Int32 Index = Low ^ b;
                    Low = High ^ CRC16TABLE_LO[Index];
                    High = CRC16TABLE_HI[Index];
                }
            }

            return (High == 0xF0 && Low == 0xB8);
        }

        /// <summary>   
        /// CRC16查找表高字节   
        /// </summary>   
        private static readonly Byte[] CRC16TABLE_HI =  
        {  
            0x00, 0x11, 0x23, 0x32, 0x46, 0x57, 0x65, 0x74, 0x8C, 0x9D, 0xAF, 0xBE, 0xCA, 0xDB, 0xE9, 0xF8,  
            0x10, 0x01, 0x33, 0x22, 0x56, 0x47, 0x75, 0x64, 0x9C, 0x8D, 0xBF, 0xAE, 0xDA, 0xCB, 0xF9, 0xE8,  
            0x21, 0x30, 0x02, 0x13, 0x67, 0x76, 0x44, 0x55, 0xAD, 0xBC, 0x8E, 0x9F, 0xEB, 0xFA, 0xC8, 0xD9,  
            0x31, 0x20, 0x12, 0x03, 0x77, 0x66, 0x54, 0x45, 0xBD, 0xAC, 0x9E, 0x8F, 0xFB, 0xEA, 0xD8, 0xC9,  
            0x42, 0x53, 0x61, 0x70, 0x04, 0x15, 0x27, 0x36, 0xCE, 0xDF, 0xED, 0xFC, 0x88, 0x99, 0xAB, 0xBA,  
            0x52, 0x43, 0x71, 0x60, 0x14, 0x05, 0x37, 0x26, 0xDE, 0xCF, 0xFD, 0xEC, 0x98, 0x89, 0xBB, 0xAA,  
            0x63, 0x72, 0x40, 0x51, 0x25, 0x34, 0x06, 0x17, 0xEF, 0xFE, 0xCC, 0xDD, 0xA9, 0xB8, 0x8A, 0x9B,  
            0x73, 0x62, 0x50, 0x41, 0x35, 0x24, 0x16, 0x07, 0xFF, 0xEE, 0xDC, 0xCD, 0xB9, 0xA8, 0x9A, 0x8B,  
            0x84, 0x95, 0xA7, 0xB6, 0xC2, 0xD3, 0xE1, 0xF0, 0x08, 0x19, 0x2B, 0x3A, 0x4E, 0x5F, 0x6D, 0x7C,  
            0x94, 0x85, 0xB7, 0xA6, 0xD2, 0xC3, 0xF1, 0xE0, 0x18, 0x09, 0x3B, 0x2A, 0x5E, 0x4F, 0x7D, 0x6C,  
            0xA5, 0xB4, 0x86, 0x97, 0xE3, 0xF2, 0xC0, 0xD1, 0x29, 0x38, 0x0A, 0x1B, 0x6F, 0x7E, 0x4C, 0x5D,  
            0xB5, 0xA4, 0x96, 0x87, 0xF3, 0xE2, 0xD0, 0xC1, 0x39, 0x28, 0x1A, 0x0B, 0x7F, 0x6E, 0x5C, 0x4D,  
            0xC6, 0xD7, 0xE5, 0xF4, 0x80, 0x91, 0xA3, 0xB2, 0x4A, 0x5B, 0x69, 0x78, 0x0C, 0x1D, 0x2F, 0x3E,  
            0xD6, 0xC7, 0xF5, 0xE4, 0x90, 0x81, 0xB3, 0xA2, 0x5A, 0x4B, 0x79, 0x68, 0x1C, 0x0D, 0x3F, 0x2E,  
            0xE7, 0xF6, 0xC4, 0xD5, 0xA1, 0xB0, 0x82, 0x93, 0x6B, 0x7A, 0x48, 0x59, 0x2D, 0x3C, 0x0E, 0x1F,  
            0xF7, 0xE6, 0xD4, 0xC5, 0xB1, 0xA0, 0x92, 0x83, 0x7B, 0x6A, 0x58, 0x49, 0x3D, 0x2C, 0x1E, 0x0F  
        };

        /// <summary>   
        /// CRC16查找表低字节   
        /// </summary>   
        private static readonly Byte[] CRC16TABLE_LO =   
        {  
            0x00, 0x89, 0x12, 0x9B, 0x24, 0xAD, 0x36, 0xBF, 0x48, 0xC1, 0x5A, 0xD3, 0x6C, 0xE5, 0x7E, 0xF7,  
            0x81, 0x08, 0x93, 0x1A, 0xA5, 0x2C, 0xB7, 0x3E, 0xC9, 0x40, 0xDB, 0x52, 0xED, 0x64, 0xFF, 0x76,  
            0x02, 0x8B, 0x10, 0x99, 0x26, 0xAF, 0x34, 0xBD, 0x4A, 0xC3, 0x58, 0xD1, 0x6E, 0xE7, 0x7C, 0xF5,  
            0x83, 0x0A, 0x91, 0x18, 0xA7, 0x2E, 0xB5, 0x3C, 0xCB, 0x42, 0xD9, 0x50, 0xEF, 0x66, 0xFD, 0x74,  
            0x04, 0x8D, 0x16, 0x9F, 0x20, 0xA9, 0x32, 0xBB, 0x4C, 0xC5, 0x5E, 0xD7, 0x68, 0xE1, 0x7A, 0xF3,  
            0x85, 0x0C, 0x97, 0x1E, 0xA1, 0x28, 0xB3, 0x3A, 0xCD, 0x44, 0xDF, 0x56, 0xE9, 0x60, 0xFB, 0x72,  
            0x06, 0x8F, 0x14, 0x9D, 0x22, 0xAB, 0x30, 0xB9, 0x4E, 0xC7, 0x5C, 0xD5, 0x6A, 0xE3, 0x78, 0xF1,  
            0x87, 0x0E, 0x95, 0x1C, 0xA3, 0x2A, 0xB1, 0x38, 0xCF, 0x46, 0xDD, 0x54, 0xEB, 0x62, 0xF9, 0x70,  
            0x08, 0x81, 0x1A, 0x93, 0x2C, 0xA5, 0x3E, 0xB7, 0x40, 0xC9, 0x52, 0xDB, 0x64, 0xED, 0x76, 0xFF,  
            0x89, 0x00, 0x9B, 0x12, 0xAD, 0x24, 0xBF, 0x36, 0xC1, 0x48, 0xD3, 0x5A, 0xE5, 0x6C, 0xF7, 0x7E,  
            0x0A, 0x83, 0x18, 0x91, 0x2E, 0xA7, 0x3C, 0xB5, 0x42, 0xCB, 0x50, 0xD9, 0x66, 0xEF, 0x74, 0xFD,  
            0x8B, 0x02, 0x99, 0x10, 0xAF, 0x26, 0xBD, 0x34, 0xC3, 0x4A, 0xD1, 0x58, 0xE7, 0x6E, 0xF5, 0x7C,  
            0x0C, 0x85, 0x1E, 0x97, 0x28, 0xA1, 0x3A, 0xB3, 0x44, 0xCD, 0x56, 0xDF, 0x60, 0xE9, 0x72, 0xFB,  
            0x8D, 0x04, 0x9F, 0x16, 0xA9, 0x20, 0xBB, 0x32, 0xC5, 0x4C, 0xD7, 0x5E, 0xE1, 0x68, 0xF3, 0x7A,  
            0x0E, 0x87, 0x1C, 0x95, 0x2A, 0xA3, 0x38, 0xB1, 0x46, 0xCF, 0x54, 0xDD, 0x62, 0xEB, 0x70, 0xF9,  
            0x8F, 0x06, 0x9D, 0x14, 0xAB, 0x22, 0xB9, 0x30, 0xC7, 0x4E, 0xD5, 0x5C, 0xE3, 0x6A, 0xF1, 0x78  
        };
    }

CRC-32-IEEE效验类

    /// <summary>   
    /// 循环冗余检验：CRC-32-IEEE 802.3查表法   
    /// </summary>   
    public static class CRCITU32
    {
        /// <summary>   
        /// 计算给定长度数据的32位CRC   
        /// </summary>   
        /// <param name="data">要计算CRC的字节数组</param>   
        /// <returns>CRC值</returns>   
        public static UInt32 GetCrc32(Byte[] data)
        {
            UInt32 crcValue = 0xFFFFFFFF;
            if (data != null)
            {
                foreach (Byte b in data)
                {
                    crcValue = (crcValue >> 8) ^ CRC32TABLE[(crcValue ^ b) & 0xFF];
                }
            }

            return ~crcValue;
        }

        private static readonly UInt32[] CRC32TABLE =  
        {  
            0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,  
            0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,  
            0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,  
            0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,  
            0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,  
            0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,  
            0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,  
            0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,  
            0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,  
            0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,  
            0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,  
            0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,  
            0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,  
            0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,  
            0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,  
            0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,  
            0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,  
            0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,  
            0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,  
            0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,  
            0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,  
            0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,  
            0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,  
            0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,  
            0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,  
            0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,  
            0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,  
            0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,  
            0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,  
            0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,  
            0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,  
            0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D  
        };
    }  

Crc16Ccitt效验类

    /// <summary>
    /// 初始效验值
    /// </summary>
    public enum InitialCrcValue { Zeros, NonZero1 = 0xffff, NonZero2 = 0x1D0F }

    /// <summary>
    /// Crc16Ccitt效验类
    /// </summary>
    public class Crc16Ccitt
    {
        const ushort poly = 4129;
        ushort[] table = new ushort[256];
        ushort initialValue = 0;

        public ushort ComputeChecksum(byte[] bytes)
        {
            ushort crc = this.initialValue;
            for (int i = 0; i < bytes.Length; ++i)
            {
                crc = (ushort)((crc << 8) ^ table[((crc >> 8) ^ (0xff & bytes[i]))]);
            }
            return crc;
        }

        public byte[] ComputeChecksumBytes(byte[] bytes)
        {
            ushort crc = ComputeChecksum(bytes);
            return BitConverter.GetBytes(crc);
        }

        public Crc16Ccitt(InitialCrcValue initialValue)
        {
            this.initialValue = (ushort)initialValue;
            ushort temp, a;
            for (int i = 0; i < table.Length; ++i)
            {
                temp = 0;
                a = (ushort)(i << 8);
                for (int j = 0; j < 8; ++j)
                {
                    if (((temp ^ a) & 0x8000) != 0)
                    {
                        temp = (ushort)((temp << 1) ^ poly);
                    }
                    else
                    {
                        temp <<= 1;
                    }
                    a <<= 1;
                }
                table[i] = temp;
            }
        }
    }