Add4.hdl Assistance

[Eat_Whatever]

Hi,

I'm trying to implement the 4-bit adder for project 2, and I'm using 1 half adder and 3 full adders, I'm new to adders, and I was wondering if I am heading into the right direction so far?

[cadet1620]

Eat_Whatever wrote

Hi,

I'm trying to implement the 4-bit adder for project 2, and I'm using 1 half adder and 3 full adders, I'm new to adders, and I was wondering if I am heading into the right direction so far?

Sounds good.  Just keep adding full adders until you get to 16-bits.  8-)

--Mark

[Eat_Whatever]

Ah thanks. But why to 16-bit? If I'm only implementing the 4-bit adder.

[cadet1620]

The adder in project 2 is Add16.hdl which adds 2 16-bit numbers.

Are you still thinking about the 4-bit examples form the "background" introductory section?

--Mark

[Eat_Whatever]

Oh yes, I got that to work when I ran the script, however, I'm still having trouble with the Add4.hdl which my instructor decided to add into the project, which adds two 4-bit number, but whenever I implemented using the 1 half adder and 3 full adders, it runs the test script but fails after hitting the last line. I'm not sure what to do...

[cadet1620]

Does your instructor's Add4 have a carry input and output? If it is intended as a building block for Add16 that is likely the case.  If so, think about how you need to handle the carry in.

--Mark