Calcul du CRC 16

CRC16(0x16) = 0x533F

3A

0x33 0x41

CRC16("3A") = 0x70D5

static class CRC {
	static uint CRC16(byte[] buf)
	{
		uint crc = 0xFFFF;
		for (int pos = 0; pos < buf.Length; pos++)
		{
			crc ^= (uint)buf[pos];    // XOR byte into least sig. byte of crc

			for (int i = 8; i != 0; i--) {    // Loop over each bit
				if ((crc & 0x0001) != 0) {      // If the LSB is set
					crc >>= 1;                    // Shift right and XOR 0xA001
					crc ^= 0xA001;
				}
			else                            // Else LSB is not set
				crc >>= 1;                    // Just shift right
			}
		}

		return crc;
	}

	static void Main(string[] args) {
		byte[] data = System.Text.Encoding.ASCII.GetBytes("3A");
		System.Console.WriteLine(CRC16(data).ToString("X"));
	}
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplicationCRC
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void buttonCalcul_Click(object sender, EventArgs e)
        {
           
         
            byte[] data = System.Text.Encoding.ASCII.GetBytes(textBoxSaisie.Text);
            labelAffichage.Text = (CRC16(data).ToString("X"));


        }

        static uint CRC16(byte[] buf)
        {
            uint crc = 0xFFFF;
            for (int pos = 0; pos < buf.Length; pos++)
            {
                crc ^= (uint)buf[pos];   

                for (int i = 8; i != 0; i--)
                {  
                    if ((crc & 0x0001) != 0)
                    {  
                        crc >>= 1;                   
                        crc ^= 0xA001;
                    }
                    else                            
                        crc >>= 1;                  
                }
            }

            return crc;
        }

    }


}