let's talk informally :
We know that
means there are 4 input lines, 2 select lines, and 1 output line. In other words, we can say that
To map 4 input lines we need 1 MUX. Why?? because there are 4 input line and only one
MUX is enough to map those lines.
So this is the idea to implement higher MUX using lower MUX.
Example:
1. Implement
using
.
Solution:-
let's talk about
first
To implement 4 input lines we need ................... 1 MUX
" " 1 input line we need ......................1/4 MUX
In
there are 64 input lines
To implement 64 input lines we need ..................64*(1/4)=16 MUX //level 1
But 16 MUX will have 16 output lines, we have to map until the total output line is 1 or less than 1, again consider these 16 output lines as input lines for next level MUX
To implement 16 input lines we need ..................16*(1/4)=4 MUX //level 2
Again 4 MUX will have 4 output lines, we have to map until the total output line is 1 or less than 1, again consider these 4 output lines as input lines for next level MUX.
To implement 4 input lines we need .................. 4*(1/4)=1 MUX //level3
Now we can stop. Think Why??
The total number of
MUX required to construct
= 
Now we will see a formula to directly calculate the number of level and MUX.