A Multiplexer (MUX) can be described as a combinational logic circuit used to select only one input among several inputs based on selection lines
This can act as a digital switch
This is also called as data selector
In a MUX, there can be 2^n inputs, n selection lines and 1 output
‘n’ must be atleast 1
Diagram of a 2^n MUX
When we are designing the Truth Table of a MUX, we have to consider only the selection lines, not inputs as out is dependent on selection lines and not on inputs.
Design of a 2 X 1 MUX
2 X 1 MUX means 2 inputs and 1 output
2 ^ n=1
2^1=1^1
So n=1
Selection line may have either 0 or 1. If it is 0, output will be input at 0 port, means D0 and D1 for selection line 1.
So, Y=D0S’ + D1S
Logic Circuit
In all MUX logic circuit, there will be an OR gate at the end.
4 X 1 MUX
2^n=4
2^2=2^2
N=2
So, 2 selection lines and 4 inputs
Truth Table of 4 X 1 MUX
Boolean expression of this truth table is as follows:
Y=D0S0’S1’ + D1S0’S1 + D2S0S1’ + D3S0S1
Logic Circuit
This post first appeared on Tutorial Site On Computer Programming Languages F, please read the originial post: here
