my question is:
i have two inputs each input is BCD 4-bit. going to perform subtraction in 2 full adder.
when i have 6-4 = 2 there is no problem so far.
the problem is
when i have 4 - 6 = -2 is the problem.
so what i need is swap the input that is instead of taking making the input 4 would be 6, and so on. for the whole BCD numbers.
0011
-
0100
--------
====> 0100 convert it then add it to Full Adder and make the (C0 = 1) will give me an error of the sum.
that's why i want invert the input to get the right answer.
so please if anyone have an idea of how to swap input by compare the input
i have two inputs each input is BCD 4-bit. going to perform subtraction in 2 full adder.
when i have 6-4 = 2 there is no problem so far.
the problem is
when i have 4 - 6 = -2 is the problem.
so what i need is swap the input that is instead of taking making the input 4 would be 6, and so on. for the whole BCD numbers.
0011
-
0100
--------
====> 0100 convert it then add it to Full Adder and make the (C0 = 1) will give me an error of the sum.
that's why i want invert the input to get the right answer.
so please if anyone have an idea of how to swap input by compare the input