using System;

​

public class Program

{

    public static uint crc_val(byte [] data_val) 

    {   

        uint crc_value = 0xffff;

        foreach (var val in data_val)

        {

            crc_value ^= val;

            for (var i = 0; i < 8; i++)

            {

                if ((crc_value & 0x0001) != 0)

                    crc_value = (crc_value >> 1) ^ 0xa001;

                else

                    crc_value = crc_value >> 1;

            }

        }

        return crc_value;

     } 

    public static void Main()

    {

        var data = new byte[] { 0x01, 0x03, 0x00, 0x00, 0x00 };

        Console.WriteLine(crc_val(data));

    }

}