public static void SwitchTo30()
        {
            var device = new PciDevice(_access, 0, 20, 0);
            var mask   = device.ReadUInt32(0xD4);

            device.Write(0xD0, mask);
        }
        public static void SwitchTo20()
        {
            var device = new PciDevice(_access, 0, 20, 0);

            device.Write(0xD0, (uint)0);
        }
        public static void SetRouting(uint value)
        {
            var device = new PciDevice(_access, 0, 20, 0);

            device.Write(0xD0, value);
        }