RegisterExtensions.cs

using System;
using System.Collections.Generic;

namespace StructDesigner.Runtime.Extensions
{
    public static class RegisterExtensions
    {
        /// <summary>
        /// Converts an array of registers into a byte array.
        /// </summary>
        /// <param name="values"></param>
        /// <returns></returns>
        public static byte[] ToBytes(this ushort[] values)
        {
            //Allocate space for the bytes.
            var bytes = new List<byte>(values.Length * 2);

            foreach (var value in values)
            {
                bytes.Add((byte)(value >> 8));
                bytes.Add((byte)value);
            }

            return bytes.ToArray();
        }

        /// <summary>
        /// Converts a byte array into registers. Requires that the source array is of an even length.
        /// </summary>
        /// <param name="values"></param>
        /// <returns></returns>
        public static ushort[] ToRegisters(this byte[] values)
        {
            if (values.Length % 2 != 0)
                throw new ArgumentException($"The length of '{nameof(values)}' must be even.", nameof(values));

            //Calculate how many regsiters we will have
            var numberOfRegisters = values.Length / 2;

            //Create a place for the registers.
            var registers = new ushort[numberOfRegisters];

            //Deal with each register
            for (var index = 0; index < numberOfRegisters; index++)
            {
                var msb = (ushort)(((ushort)values[index * 2]) << 8);
                var lsb = (ushort)values[(index * 2) + 1];

                registers[index] = (ushort)(msb | lsb);
            }

            return registers;
        }

        /// <summary>
        /// Gets a bit from a byte.
        /// </summary>
        /// <param name="value"></param>
        /// <param name="bitPosition"></param>
        /// <returns></returns>
        public static bool GetBit(this byte value, int bitPosition)
        {
            return (value & (1 << bitPosition)) > 0;
        }
    }
}