# Help on building a Boolean circuit

Discussion in 'Homework Help' started by Estudent1005, Jan 6, 2011.

1. ### Estudent1005 Thread Starter New Member

Jan 5, 2011
4
0
I have a homework question regarding Boolean circuit design:

Design a Boolean Circuit for checking whether a 3-bit twos complement binary number is less than -1

I've know that I need to construct a truth table for inputs bits A2, A1, and A0, but I'm lost on how to formulate the function that will produce the output.

I'm new at Boolean circuit design and need a little coaching. Any hints would be helpful...also, if you have a good website that better explains how to do this, I would love to read more about this topic...We were not given a textbook for our class, so I just need better resources.

Thanks!!

Last edited: Jan 6, 2011
2. ### StayatHomeElectronics Well-Known Member

Sep 25, 2008
864
40
Why don't you start out by drawing the truth table?

You can derive the equation from the truth table and then try to simplify using Boolean algebra or you can turn the truth table into a Karnaugh map and use that to help simplify. Google "boolean algebra" or "Karnaugh map" if you are not sure what those are.

And then, ask more questions after you do the truth table.