Development of VHDL Code for Traffic Light Controller

Development of VHDL Code for Traffic Light Controller

Abstract

This controller is able to handle a walk request button on the main street and a traffic sensor on the side street. The controller includes a user interface allowing an operator to view and modify the configuration of the device. In addition, the controller properly synchronizes its external inputs making it robust to changes in user usage. The system is implemented using a FPGA and a static RAM. Control is provided by a finite state machine embedded in the FPGA.

The controller is designed to operate a standard traffic light; it has outputs corresponding to pairs of red, yellow, and green lights on a main and side roads and inputs for a walk request button and a vehicle sensor.

In addition to operating the traffic light, the controller also has special modes for viewing and configuring the timing information for that particular light. A traffic light installed at the intersection of a heavily traveled road and a much smaller road could be configured to have a much longer ”go period” for the heavily traffic road.

Notation used for the traffic lights control

SOFTWARE: VHDL.

DEVELOPMENT TOOLS: XILINX ISE, MODELSIM.