# Boolean function realisation using MUX 4/1 and 8/1

#### xxxyyy

Joined Oct 7, 2011
34
Here is my homework:

Realise Boolean function AB+BCD+ACD using:
1)Multiplexer 4/1 and required logic gates
2)Only Multiplexers 4/1
3)Only Multiplexers 8/1

I have done task number 1,here is photo:
Rich (BB code):
http://imageshack.us/photo/my-images/830/675867959.jpg/
How can I do tasks 2 and 3?
I appreciate any help.
Greetings

#### Georacer

Joined Nov 25, 2009
5,182
It seems that the implementation of the function CD is were you get stuck. Since there is no restriction in the number of MUXs used, why don't you use another 4-to-1 MUX to construct the function CD and then feed the result in your original solution?

As for the 8-to-1 MUX, you can use 3 variables to select the input and need only one variable as an input. That way you don't really need to use any gate.

#### xxxyyy

Joined Oct 7, 2011
34
Thanks for fast answer Georacer.
How can I realise logical 'And' (C*D) using MUX 4/1?

#### Georacer

Joined Nov 25, 2009
5,182
Just implement the AND's logic function:
Rich (BB code):
A B AND
-------
0 0 | 0
0 1 | 0
1 0 | 0
1 1 | 1

#### xxxyyy

Joined Oct 7, 2011
34
Last edited:

#### Georacer

Joined Nov 25, 2009
5,182
Yep, that's it! You should do exactly as you said.