ECE 171: Introduction to Digital Circuits

Fall 1999

Rev: 11.15.99

Design Project 2

Problem Description

Continuing with Project 1, you will now simulate that circuit to determine whether your design works or not. If you find that your design does not work, you will repeat the design-simulate loop until it does. A large part of the grade for this project is based on how thoroughly and clearly you document your work.

To complete the project

1. Carefully work your way through Mentor Tutotial 3 using your spike1 circuit.
2. Use the process described in the tutorial to apply a binary count sequence to the inputs of your circuit, add traces for input and output signals, and run the simulation. For this circuit you don't need to check for hazards.
3. Print out the results of the simulation, and carefully check to see if the results are correct for all input combinations.
4. If the results are not correct, document the error and possible cause of it. You may want to add probes and re-run the simulation to see logic levels on intermediate points. Fix the problem, re-design the circuit, and then simulate it again. Repeat this step until the circuit output is correct for every input combination.

Final Report

A formal report of the final design is to be written at the end of the project. It must be typed and include the following sections. These sections must be clearly labeled in your report. The quality of the report should be similar to what you would turn into your manager if you were working at an engineering firm.

• Introduction
  Describes the project and what is to be accomplished.
• Changes
  Describe all of the changes made to the design completed in Project1.
• Final Expressions
  The final boolean algebra expressions used in the circuit design. This may be the same as for Project 1 if your original design worked correctly.
• Final Schematic
  A schematic of the final circuit printed out from Mentor.
• Simulation Print-Out
  A thoroughly labeled printout of the simulation. This includes labeling all inputs and outputs. To make this readable, convert each of the 6-inputs to the Octal equivalent and whether it is a letter or number. Labeling the printout allows for someone else to understand the printout without looking at the rest of the document.
• Analysis
  List the components and show the schematic. Again, this may be the same as Project 1 if your original design worked correctly. More credit will be given to designs that use fewer ICs.
• Postscript
  Describe what you learned from this project, if anything. Was this project worthwhile? Your comments will be used to improve this project for future classes and will not affect your grade.
• Signed Statement
  To receive credit you must do this project yourself and sign the statement to that effect below.
  
  

I do hereby affirm that I designed this circuit by myself.

Signed __________________________________

Date _______________

Grading

Project 2 is worth 15 points of 50 total project points.