[SOLVED] MUX + Emulating Different Gates - Seeking Help

Hello all (First post on forum)

I understand that I have yet to contribute anything to this community and therefore you will be unlikely to help me, but I'm hoping someone will find it in their heart to offer assistance.
Basically I am revising for a University resit exam that's coming up for a Computer Systems module. For the most part, I can make sense of it. There are a couple of questions in a practice paper however that I just can't get my head around.

One of them being this:

Sketch a 4 input MUX used to emulate a NOR gate

Click to expand...

It's fair to say that my first year of University didn't go well, so my understanding of a lot of this is being made in a final attempt to redeem myself. I've spent hours now looking around the internet for a solid explanation of how this works, and how the diagram is supposed to look. However I'm only finding shreds of information from different sources, so I don't know if what I am finding is accurate or relevant to what I might need to accomplish in this paper.

If anyone here can help me it would be greatly appreciated, even if it's just a diagram then hopefully I will be able to look at it and make sense of how it's working.

Kind Regards

Hi.

It's just a matter of searching the web. Here's the answer.

I came across these before but quickly shrugged and moved on as I wasn't understanding it (A bad habit I know)

Working on this one ASIC-SoC-VLSI Design: Draw NOR gate using MUX.

I see that A and B are inputs, but what is the S that the A is connected to? And why is there a 0 going into a 1? From the image I assume this is based of two inputs, if I needed four would it be a simple case of adding C and D?

As you can no doubt tell I am a complete idiot when it comes to this module, if anyone or yourself could just explain this diagram to me then that would be great. Maybe it will come to me when I wake up in the morning, with a fresh mind not cluttered by trying to remember the other possible questions that might come up regarding huffman coding and arduino programming.

Either way thanks for your help Protoyp_V1.0 - I appreciate it and it's definitely given me something to work with now instead of just roaming around the web lost.

Regards

S stand for (S)elect input. Just read the true table, and you'll understand.

Whenever S is true, output always reflect A input regardless of B. And when S is false, output always reflect B input regardless of A.

Hey, sorry for the long time to reply, I've been caught up in work and some much needed sleep. Thanks so much for taking the time to help me, I really appreciate it and now I have a better understanding of it should it come up in the exam.

Many thanks!