CPSC 330 - Spring 2013
Homework 2
Due Wednesday, Feb. 27
Each student must turn in a separate set of homework solutions,
but you may work together in study groups with other students
from the class. Include the names of your study group members
on the solution set you submit.
Also, please provide sufficient space for your calculations and
answers so that grading will be easier.
Appendix C (see http://www.cs.colostate.edu/~malaiya/470/Appendix-C.pdf)
1. C.5 - Show NOR is universal by implementing (a) two-input AND, (b)
two-input OR, and (c) one-input NOT functions with one or more
two-input NOR gates.
2. C.7 - Construct the truth table for a four-input odd parity function.
3. C.8 - Give a simplified logic expression for the odd parity function
and implement the expression in a circuit with AND and OR gates.
Show any inverted signal by using a bubble on the gate input.
4. C.14 - Implement the switching element as described using two two-input
muxes.
5. Design a modulo-3 counter using two D flip-flops. (There is no input.)
Use a truth table with don't care values where appropriate.
QA(t) QB(t) | QA(t+1) QB(t+1)
------------+----------------
Simplify the logic expressions for the next state values, and draw the
resulting circuit.
6. Design a modulo-3 counter using two JK flip-flops. (There is no input.)
Use a truth table with don't care values where appropriate.
QA(t) QB(t) | JA KA JB KB | QA(t+1) QB(t+1)
------------+-------------+----------------
Simplify the logic expressions for the JK values, and draw the
resulting circuit.
7. C.40 - Design a 3-bit Gray code up counter using three D flip-flops.
(a) Design the circuit where "inc" is the single input and do not
include "reset". The truth table can have the form:
inc QA(t) QB(t) QC(t) | QA(t+1) QB(t+1) QC(t+1)
----------------------+------------------------
Use 4x4 Kmaps to simplify the logic expressions for the next
state values. The use of a PLA is optional; you can instead
draw individual gates in the circuit.
(b) Add the "reset" function using the technique described in the
notes.