# Hello, I have the problem looking for a solution. (A digital circuit)

#### KAlex610

Joined Apr 9, 2023
6
Build a circuit that has two 8-bit two’s complement numbers U and
W as its inputs and a single 1-bit output R, which is 1 when W − U is
negative and 0 otherwise.
You are not allowed to use the Arithmetic and Plexers libraries; how-
ever, an 8-bit adder, incrementer and multiplexer, implemented via gates,
are provided on the design board for your convenience. Feel free to use
them, or build your own if you prefer.

#### dl324

Joined Mar 30, 2015
15,835
We don't provide answers for school work. You need to show your best effort so we can see the approach you're being taught and where you're having difficulties.

What simulator are you using?

#### KAlex610

Joined Apr 9, 2023
6
We don't provide answers for school work. You need to show your best effort so we can see the approach you're being taught and where you're having difficulties.

What simulator are you using?
Logisim

#### dl324

Joined Mar 30, 2015
15,835

#### KAlex610

Joined Apr 9, 2023
6
That's what I thought. I never cared for that simulator.
Can you please give me some Idea how can I solve this problem ?

#### WBahn

Joined Mar 31, 2012
29,165
Can you please give me some Idea how can I solve this problem ?
If W is 98 and U is -49, what should R be?

How did you arrive at that?

Can you apply that same approach regardless of what W and U happen to be (each between -128 and +127)?

#### dl324

Joined Mar 30, 2015
15,835
Can you please give me some Idea how can I solve this problem ?
You have to show your best effort so we can see what approach you take.

#### KAlex610

Joined Apr 9, 2023
6
You have to show your best effort so we can see what approach you take.
This is what I have done so far... success for a few numbers, still getting errors for some

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#### KAlex610

Joined Apr 9, 2023
6
solved it

#### dl324

Joined Mar 30, 2015
15,835
solved it
Glad you solved it. I don't visit this site as often as I have in the past and choose not to have email notifications cluttering my inbox.