public static Byte2 Subtract(Byte2 a, Byte2 b)
{
var inverted = Gates.Invert16(b);
var incremented = Increment(inverted);
return(AddByte2(a, incremented, false).Low);
}
public static Byte2 Do(bool zero, bool negate, Byte2 data)
{
var selectZero = Select16.Do(zero, new Byte2(0), data);
var selectNegate = Select16.Do(negate, Gates.Invert16(selectZero), selectZero);
return(selectNegate);
}
public static Byte2 Do(InstructionDecoder.Operation operation,
Byte2 dataX,
Byte2 dataY)
{
var transformedDataX = UnaryArithmeticLogicUnit.Do(operation.zx, operation.nx, dataX);
var transformedDataY = UnaryArithmeticLogicUnit.Do(operation.zy, operation.ny, dataY);
var and = Gates.And16(transformedDataX, transformedDataY);
var add = Arithmetics.AddByte2(transformedDataX, transformedDataY, false);
var selected = Select16.Do(operation.Function, add.Low, and);
var inverted = Gates.Invert16(selected);
var output = Select16.Do(operation.NegateOutput, inverted, selected);
return(output);
}
