COMP 150 Homework 2

This is an individual assignment, not a pair assignment.

Turn it in on paper.  It is due in class, not at midnight.

1. (5 points) Create circuit diagram for the Boolean expression (AB + C)D.
   
2. (5 points) Write a Boolean expression for the output of this circuit:
    
3. (5 points) Write a Truth Table for the Boolean expression (A+B')C.  Include columns for the inputs A, B, and C.  Please include a column in your truth table for the output of each intermediate expression.  Include rows for all 8 combinations of input variables.
4. (5 points)  A three-way majority circuit is one with three inputs and a single output which is set to 1 whenever two or more of the inputs (the majority) are set to 1.   There are eight possible combinations for the input settings. Please give a truth table which lists rows for all eight input combinations along with the output setting for each case.
5. (5 points)  Write a Boolean expression for the output of the three-way majority. 
6. (5 points)  Construct a circuit which implements the three-way majority function discussed in the previous two questions.  You may use AND and OR gates with more than 2 inputs to make it easier.

Please turn in your answers on PAPER IN CLASS.  (Add the extra creadit portion below if you like.)

Extra Credit (5 points)

Interestingly, any given boolean function can be calculated by a circuit consisting solely of NAND gates.

Create a circuit, using only NAND gates, which has the same overall behavior as a NOT gate. Your circuit should have one input and one output .

Create a circuit, using only NAND gates, which has the same overall behavior as an AND gate. Your circuit should have two inputs and one output.

Create a circuit, using only NAND gates, which has the same overall behavior as an AND gate. Your circuit should have two inputs and one output.