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

Discussion in 'Homework Help' started by xxxyyy, Nov 13, 2011.

1. ### xxxyyy Thread Starter Member

Oct 7, 2011
34
1
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:
Code ( (Unknown Language)):
1. http://imageshack.us/photo/my-images/830/675867959.jpg/
How can I do tasks 2 and 3?
I appreciate any help.
Greetings

2. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
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.

3. ### xxxyyy Thread Starter Member

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

4. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
Just implement the AND's logic function:
Code ( (Unknown Language)):
1.
2. A B AND
3. -------
4. 0 0 | 0
5. 0 1 | 0
6. 1 0 | 0
7. 1 1 | 1
8.

5. ### xxxyyy Thread Starter Member

Oct 7, 2011
34
1
Last edited: Nov 13, 2011
6. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
Yep, that's it! You should do exactly as you said.