Multiplexer Help Please

Thread Starter


Joined Jan 25, 2015
Hi I want to know how to do part C of this question. I have done part A and B but I don't know how to start part C. Here is the question :
Part A
Binary to Gray Code Conversion Binary to gray code conversion is achieved by keeping the same MSB bit and Xoring all remaining bits with each other to create the correct gray code number. Using this, create a circuit to convert a binary number to a gray coded number Tasks: Create the necessary circuit to take a 6 input number and convert it to the correct gray code number

Part B
Gray Code to Binary Conversion Gray code to binary conversion involves keeping the same MSB bit but using successive MSB bits to calculate the appropriate sum value between the input bit and the more significant bit of the binary number. Using this or otherwise, create a circuit that will convert a gray code number into the appropriate binary number. Tasks: Create the necessary circuit to take a 6 input number and convert it to the binary number

Part C
Add the necessary circuitry to enable selecting the conversion to perform Using multiplexers or otherwise, add circuitry to allow for the selection of the conversion to perform. As part of this, investigate the use of the following features in LogiSim o Built in plexers Tasks: Implement an easy to use selection mechanism to control the conversion output that is to be displayed

We haven't done multiplexers yet so I am having a hard time. Can you just show me the drawing of the circuit in logisim format because I will understand it much better if I have an example.

Thank you very much.


Joined Mar 14, 2008
A digital multiplexer can be designed using two-input AND gates.
The signal bit goes to one input and the control bit goes to the other.
The AND gate outputs then goes to a multiple input OR gate which accepts inputs from the other AND gate outputs for that bit.
You can also use two NAND gates to get the AND-OR function.


Joined Mar 31, 2012
How about showing use what you've done for Parts A and B since those are the basis for the work in Part C.

Also, read about multiplexers. A basic multiplexer just takes two input signals, X and Y, and depending on the value of a control bit, S, echoes on or the other at the output. So if S is 0 then the output is equal to X while if it is 1 the output is equal to Y. Think of it as a channel selector.