# help with simplifying POS:

Discussion in 'Homework Help' started by shawd, Sep 20, 2009.

1. ### shawd Thread Starter Member

Sep 20, 2009
16
1
i have a four input circuit, and so far i have these equations down but im not sure how to simplify it more if i can. this is the truth table:

ABCD F
0000 |1
0001 |1
0010 |0
0011 |1
0100 |1
0101 |1
0110 |1
0111 |1
1000 |1
1001 |1
1010 |1
1011 |1
1100 |0
1101 |1
1110 |0
1111 |0

so far i have this:

(ABC)' (A' + B' + D)(A + B + C' + D)

any help would be appreciated. Im pretty sure the the last 2 might factor out a D and maybe make an xor gate out of the A and B but im not for sure. Also if anyone has any links to threads on here or elsewhere there would be a good place to help practice making schematics or tips on making schematics please share. I'm good at normal schematics, but now I'm working on a 7 segment display so i have 7 outputs, and I'm having trouble with combining all my work into one thing.

2. ### hgmjr Retired Moderator

Jan 28, 2005
9,029
219
Review the section in the AAC ebook on POS and SOP boolean algebra.

hgmjr

3. ### shawd Thread Starter Member

Sep 20, 2009
16
1
thank you.

btw my equations are wrong on the first part, its actually:

(A' + B' + C')(A' + B' + D)(A + B + C' + D)

Mar 20, 2007
1,068
4