Recently I had an exam where we were tested on logic circuits. I encountered something on that exam that I had never encountered before. Forgive me for I do not remember the exact problem given and we have not received our grade for it; however I will describe the problem.
The problem had a 3 or 4 inputs. We were told to simplify then draw a logic circuit design for that simplification. However, when I simplified, I ended up eliminating the other inputs and ended up literally with just
A
I had another problem like this as well where there was 4 inputs and when I simplified, I ended up with three. My question is:
What do I do with the eliminated inputs? Do I just not have it on the circuit? How would I draw it?
Typically an output is a requirement which would not be eliminated, even if it ends up being dependent on a single input. If input A flows through to output Y, just connect A to Y in the diagram. If output Y is always 0 or 1, connect an incoming 0 or 1 to output Y.
On the other hand, inputs are possible, not required, factors in the definition of the problem. Inputs that have no bearing on the output need not be shown in the circuit diagram at all.