CSE370 Laboratory Assignment 2

Computer Aided Design Tools for Digital Design

Distributed: April 4/5, 2005
Due: By the end of lab section


In this laboratory assignment you will continue to learn how to use AldecHDL to enter basic schematic diagrams and simulate them. We will expect you to use this tool to do a large part of your written assignments. By the end of this lab you should feel comfortable entering a schematic for a design, setting up simulation stimuli, and verifying that your circuit is correct.

Each student should complete this lab individually.


1.      Complete the entire introductory tutorial for Aldec ActiveHDL.  You can get a head start on the tutorial before your lab session so you will have plenty of time to complete the lab.  You will also be using Aldec for part of homework assignment #2.

2.      Design the following IF-THEN-ELSE circuit. It has three inputs, S, A and B, and one output, ‘out’. This circuit acts like a data switch: If S = 1, then it “connects” the output to A; if S = 0, it “connects” the output to B.

   if (S) then out = A;
          else out = B;

Draw a schematic for this circuit using Active-HDL and the chip parts from the lib370 library (e.g. c7400).  Try to use as few chips as possible – extra credit will be given if you can do it with just one 7400 or 7402. Using a counter stimulator, simulate this circuit for all possible input values and show that your circuit computes the right values. Show the result of the simulation to a TA and have him/her check off this part of the lab before you go on to part 3.

3.      Using the schematic from part 2, construct a circuit for this function on the prototyping board, connecting the inputs to switches, and the output to an LED.  Demonstrate your circuit to a TA and have them check you off as having completed this laboratory assignment. They may ask you to show them your work and explain your circuit.

Hand in

Hand in the checked off printout of your schematic and simulation output waveform.