Logic Problem

[qaa541]

Originally posted by: FrustratedUser

Originally posted by: NogginBoink
I want a logic 1 output when any single input is logic 1. Else, I want a logic 0 output.

Make a good old truth table and your your boolean skillz. Better yet, go with a Karnaugh (??? spelling) diagram.

Why hasnt anyone said this before? Minterms to the rescue!

 

[Steve]

Have you tried this in Highly Technical?

 

[amoeba]

karnaugh maps not so great with xor type functions.

I believe OP wants an 8 bit parity which is just bit 1 xor bit 2 xor bit 3 ....etc.

 

[mchammer187]

i dont see any other way around it rather than doing

A * ! (B C D E F G H) + B * !(A C D E F G H) + C * !(A B D E F G H) + D *!( A B C E F G H) + E *! (A B C D F G H) + F *!(A B C D E G H) + G*!(A B C D E F H) + H*!(A B C D E F G)

 

[sciencewhiz]

Originally posted by: FrustratedUser

Originally posted by: NogginBoink
I want a logic 1 output when any single input is logic 1. Else, I want a logic 0 output.

Make a good old truth table and your your boolean skillz. Better yet, go with a Karnaugh (??? spelling) diagram.

I'd like to see you do an 8 input K-map.

 

[FrustratedUser]

Originally posted by: sciencewhiz

Originally posted by: FrustratedUser

Originally posted by: NogginBoink
I want a logic 1 output when any single input is logic 1. Else, I want a logic 0 output.

Make a good old truth table and your your boolean skillz. Better yet, go with a Karnaugh (??? spelling) diagram.

I'd like to see you do an 8 input K-map.

I don't 😀

 

[vrbaba]

Originally posted by: mchammer187
i dont see any other way around it rather than doing

A * ! (B C D E F G H) + B * !(A C D E F G H) + C * !(A B D E F G H) + D *!( A B C E F G H) + E *! (A B C D F G H) + F *!(A B C D E G H) + G*!(A B C D E F H) + H*!(A B C D E F G)

i dont understand the spaces. But i think ur saying this:
A * ! (B+C+D+E+F+G+H) + B * !(A+ C+ D+ E+ F+ G+ H) + .....

you get the idea. Yea, That Works.

I think if you expand it out and try some logical rules, you can minimize the expression.

Edit: if you are trying to put this into a diagram with simplest logical operators, you will need to exapnd the 7 input OR to 2 each like a chained OR. So it'll end up being really complicated in the software diagram. I suggest trying to simplify the expression and go from there.