public void TestCCF()
        {
            var device = TestUtils.CreateTestDevice();
            var cpu    = device.CPU;
            var alu    = new ALU(cpu);

            Assert.True(cpu.Registers.GetFlag(CpuFlags.CarryFlag)); // Carry flag starts off set
            alu.CCF();
            Assert.False(cpu.Registers.GetFlag(CpuFlags.CarryFlag));
            alu.CCF();
            Assert.True(cpu.Registers.GetFlag(CpuFlags.CarryFlag));
        }