CS 232: Project #1

Project 1: Combinational Circuits

Main course page

Purpose: to give you experience with basic digital design components.


  1. Create a circuit with 4 inputs, treated as a 4-bit positive binary integer. The circuit should output a 1 if the input is a prime number and 0 otherwise.

    Simluate your circuit by testing all possible combinations of inputs, similar to the way we tested the circuit in the lab exercise. Take a screen shot of both your final circuit design and your simulation.

  2. Create a circuit that has two components. One component should be a counter, which is available as a module. The important inputs to the counter are a clock and a reset button.

    The second part of the circuit should be a combinational circuit that controls the six lights of a 4-way traffic light. There are NS-red, NS-green, and NS-yellow, EW-red, EW-green, and EW-yellow. They should follow the timings below, given the 4-bit input from the counter.

    Input ValuesLight setting
    0N/S Red, E/W Red
    1-5N/S Green, E/W Red
    6-7N/S Yellow, E/W Red
    8N/S Red, E/W Red
    9-13N/S Red, E/W Green
    14-15N/S Red, E/W Yellow

    Test your circuit by driving the counter with a clock. Be sure to reset the clock at the beginning of the simulation by setting the reset input to high for a short period of time. Demonstrate your six output signals for all possible inputs.

    Take a screen capture of your final circuit and your simulation.



Create a wiki page with your writeup. For each task, write a short description of the task, in your own words.


Give your wiki page the label cs232S12project1.

Put your bdf files in a folder called project1 in your private subdirectory on Academics/COMP/CS232.