# Nanding an expression ?

Discussion in 'Homework Help' started by Gingerbreadman, May 31, 2011.

May 23, 2011
3
0
Hi, i'm trying to implement the expression: F = ((B.A).(D+C))+(D.C).(B+A)
using only NAND gates.

How would i convert the function using de-morgan's theorem? I know it should not be hard yet every time i start i get stuck with the wrong answer.

If you could show me step by step so i know how it gets there that would be great.

Dave

2. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
I don't have the time to take you step by step right now, but here are some tips:

(A+B)=(A'B')'
A'=A NAND 1
(AB)=((AB)')'

You could also convert the expression to a truth table, find the Sum of Products and convert it to a NAND network. That doesn't use DeMorgan's theorem but it's more algorithmic.

May 23, 2011
3
0
Hey, thanks for answering, and quickly too !

i've just about got it, i'm just thinking about (d' . c') . (d' + c')

(where . means AND, + means OR and ' means not of course.)

I can get this !