# designing a combinational circuit that multiplies two numbers together

Discussion in 'The Projects Forum' started by perm pops, Sep 20, 2015.

1. ### perm pops Thread Starter New Member

Sep 20, 2015
2
0
So I got 4 inputs, 2 inputs that represent 1 number, and the other 2 represent the other number.
So Ill create a truth table, list all the input scenarios

How do I determine the output variables and how many bits are needed to accommodate decimal value 9?
What do I need to do to to form an algebraic expression for each output variable?

I know how to simplify them using a K-map, but as far as the truth table and stuff I'm a little lost as to how to get started. Thank guys, If I can provide some clarity or anything lmk.

2. ### absf Senior Member

Dec 29, 2010
1,493
374
Think in term of decimal first:

2 bit input has a max of 3 and biggest product is 3 * 3=9.
So the output need a 4-bit register.

The truth would be something like this.

Now are you able to create your truth table in binary?

Allen