Solve 8:1 Mux Simulation with C Program

[TimFortin]

Homework Statement

Hello all, this is my first post here although I've used this site for referencing several times. My question is regarding an 8:1 multiplexer. I need to write a c program using just &&, || and ! to simulate each gate of an 8:1 mux. We have 3 control inputs and 8 source inputs and need to have just a single output. I don't understand what the need of the 8 source inputs is when you can get the correct output by using a boolean expression on the three control inputs. So to simplify my question, how do i turn the 11 (8 source + 3 control) inputs into 1 output.
Thanks for looking

Homework Equations

ans = (!a && !b) + (!a &&b &&c) + (a && !b && !c);
This produces correct answer but does not use the source inputs at all

The Attempt at a Solution

My attemp at a solution is the equation i posted above, as well as trying to use 2 4:1 muxes and a 2:1 mux but i can't seem to make any sense of it.

 

[Mastermind_14]

Homework Statement

Hello all, this is my first post here although I've used this site for referencing several times. My question is regarding an 8:1 multiplexer. I need to write a c program using just &&, || and ! to simulate each gate of an 8:1 mux. We have 3 control inputs and 8 source inputs and need to have just a single output. I don't understand what the need of the 8 source inputs is when you can get the correct output by using a boolean expression on the three control inputs. So to simplify my question, how do i turn the 11 (8 source + 3 control) inputs into 1 output.
Thanks for looking

Homework Equations

ans = (!a && !b) + (!a &&b &&c) + (a && !b && !c);
This produces correct answer but does not use the source inputs at all

The Attempt at a Solution

My attemp at a solution is the equation i posted above, as well as trying to use 2 4:1 muxes and a 2:1 mux but i can't seem to make any sense of it.

>The first thing I want to ask is that do you know how a multiplexer works?
This is because the code that you have pasted shows that you do not fully understand how a multiplexer works.


>if you use "s0,s1,s2" as the control inputs and "a0,a1,a2,a3,a4,a5,a6,a7" as the input pins while "ans" is ur answer then the C program must assign these inputs and switches to answer in the following manner...


ans=(!s0 && !s1 && !s2 && a0 )||(s0 && !s1 && !s2 && a1 )||(!s0 && s1 && !s2 && a2 )||(s0 && s1 && !s2 && a3 )||.... till all possible values of s0,s1,s2 have been utilized.

>If you are inclined to use two 4:1 muxes and one 2:1 then you can make them the same way the 8:1 mux is made. If you still don't understand then PM me or post here.


>If you are not forced to make this program in C then i would suggest that you program it in HDL(hardware descriptive languages) like Verilog and VHDL which are meant for hardware design and verification and have nearly the same syntax like C.

I hope your problem is solved.

 

[Mene]

I would approach this problem by first understanding the purpose and function of a multiplexer. A multiplexer is a device that selects one of several input signals and forwards it to a single output line. In this case, we are dealing with an 8:1 multiplexer, which means it has 8 source inputs and 3 control inputs.

The first step would be to understand how the 8 source inputs and 3 control inputs are connected to the output. This can be done by drawing a truth table, which shows all the possible combinations of inputs and their corresponding outputs. From the given equation, it seems that the output is a function of the 3 control inputs only, but we need to make sure that it is indeed the case.

Next, I would suggest breaking down the problem into smaller parts. For example, you can start by simulating a 2:1 multiplexer using the given boolean expressions and then move on to a 4:1 multiplexer. This will help in understanding the logic behind the multiplexer and how the inputs are being selected.

In terms of using a C program, it would be helpful to first declare variables for the 8 source inputs and 3 control inputs and then use if-else statements to simulate each gate of the 8:1 multiplexer. You can also use loops to iterate through the different combinations of inputs and test the output.

Overall, the key to solving this problem is to have a clear understanding of the purpose and function of a multiplexer and to break down the problem into smaller parts to make it more manageable.