EE365: The Final Project (20 points)
Updated: Saturday, Nov 17, 2001 at 4:25 pm

The Traffic light controller

Design a traffic light controller that employs a digital system which switches lights on or off in a sequence that enables the traffic to flow and pedestrians to cross the road soon after they press a Walk button. We consider a simplified intersection at a EW (East-west) Highway and a NS (North-South) county road. There are walk buttons that a pedestrian can press at anytime.

Here are the main features of the controller:

  • The EW Highway is heavily travelled. It remains green most of the time unless (a) a vehicle nears the signal light in the NS direction or (b) a pedestrian presses the walk-button. However, when one of these events take place, the EW-light remains green for about 6-7 cycles before changing to red. Assume that an electronic sensor detects the presence of a vehicle on the NS bound street as it nears the intersection.
  • The NS street gets about 4 clock cycles of green.
  • For simplicity, assume there is no yellow light.
  • If a pedestrian presses the button the NS or EW signals will change to red (after they remain green for the required times), and the pedestrian will then get about 3 clock cycles to cross the street or the highway.
  • Once a request from a pedestrian is registered no further request will be accepted from the pedestrians even of anyone else presses the button until after traffic flows in one or the other direction.
  • Although a Pedestrian has a higher proirity over vehicles, make sure that the traffic flow is not stopped in any direction by a fun-loving pedestrian.

    The design You may (should?) work in a group of two. You must not discuss the contents of your work with other groups. Since this is a design project, I can imagine many unique approaches to solve the problem. So if two projects look similar in ideas and/or content and/or style, I have to assume that these two groups have had some interactions.

  • Use XC9500 series CPLD in this project, If you use MUXs, D-flip flops etc, use VHDL code based macros as part of your circuit.
  • Simulate your result using the "timing mode" rather than the "functional mode" of the Xilinx tool.

    The report must be written in a professional manner. Which means it must be thorough yet concise so it does not take a long time to read the report. Your projects must accompany a floppy disk with "archived versions" of the Xilinx project. The diskette will (may) not be returned.

    The grade on the project will depend on the following:

  • your method of approaching the design problem (This will test your creativity)
  • thoroughness of your work that makes these projects as "near-flawless" as can be accomplished (This will be the test of your knowledge),
  • and demonstrating "clearly" with simulations that your design works for a number of test conditions (that means as you make progress in your work, keep in mind you have to test it too). This is called "design for testability".

  • Due date Thursday, December 6 by 4:00 pm. The project will be accepted until Dec 10. Howvever the maximum grade awarded will be reduced to 15.