# Realisation of Boolean expression

Discussion in 'Homework Help' started by xxxyyy, Oct 12, 2011.

1. ### xxxyyy Thread Starter Member

Oct 7, 2011
34
1
I have this expression: ACD+ABC+BD+ACD, where underlined letters are complements.
How can I realise this function using only:
a)NAND gate
b)NOR gate
I suppose that I should transform function above to get 2 new functions,one for realisation using only NAND gates, and second for realisation using only NOR gates.How can I do it?

Last edited: Oct 12, 2011
2. ### panic mode Senior Member

Oct 10, 2011
1,328
305
I will use exclamation in front of signal to indicate that signal is inverted.

a)
NAND1 = inputs A, C, !D
NAND2 = inputs A, B, !C
NAND3 = inputs B, !D
NAND4 = A, !C, D
NAND5 = inputs are outputs from previous gates.

normally it is assumed that signals are available in direct and inverted form. if you need to create inverted signals for C and D, you can use additional pair of NANDs as inverters (just connect inputs of the NAND gate together).

b)
just use DeMorgan

NOR1 = inputs !A, !C, D
NOR2 = inputs !A, !B, C
etc.
NOR5 = inputs are from previous NOR gates.

just like with NAND, you can use NOR to make invertor by connecting inputs of the NOR gate together.

xxxyyy likes this.
3. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
This thread has been moved to Homework Help section, where it seems more fitting.