Question

Use on 4-to-1 MUX to implement the majority function

Answer 1

The majority function states that: The value of the output turns out to be true if more than hald of the values that are input by the user are 1.

The MUX table i) with A,B &C inputs and the output produced which is S is shown below,

A	B	C	S
0	0	0	0
0	0	1	0
0	1	0	0
0	1	1	1
1	0	0	0
1	0	1	1
1	1	0	1
1	1	1	1

Implementation of 4 to 1 is shown below, table ii)

A	B	S
0	0	0
0	1	C
1	0	C
1	1	0

We have made the table above from the first table that we made using 3 inputs, thus if we see then in the Table i) the values of A & B are same i.e 0 & 0 and they are producing 0. So we will club them in the table ii). Similarly the values of A & B are 0 and 1 and they are producing the same output which is the same as the value of C in table i). Hence we will club them in table ii). We will repeat the same process for row 3 & 4 for table ii) and we will get the desired table.

The Mux circuit diagram for the above will be like this: