Implementing the Car Park Occupied Slot Counting System

 Car Park Occupied Slot Counting System

Problem definition:

There is a car park with three slots and we would like to know how many of its slots are occupied at a given time. Within the design, occupied slot locations are not important.

Solution:

We can design a combinational circuit for this purpose. 

Assume that we placed a sensor over each slot which gives output logic level 1 when the slot is occupied. If the slot is empty, sensor gives output logic level 0.

 Let’s label output of sensors as binary variables s0, s1, and s2. 

The designed combinational circuit will provide the output as a two-bit binary number c1 (MSB) and c0 (LSB). Therefore, we should cover all input combinations in terms of a truth table

                                Truth Table of the Car Park Occupied Slot Counting System

logic functions for c0 and c1 in the SOP form as follows:

Verilog Description of the Car Park Occupied Slot Counting System code:1

Synthesization result of the car park occupied slot counting system

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Implementing the Car Park Occupied Slot Counting System

We can also implement the car park occupied slot counting system on Basys3 board. As in

previous applications, we provide Verilog description in which LEDs and switches on the board are connected in code:2. Here, we use Verilog description of the system in code:1 as an IP block. Therefore, we expect the reader has generated the corresponding IP block.

Car Park Occupied Slot Counting System Implemented

 on the Basys3 Board in Verilog

Improving the Car Park Occupied Slot Counting System

We can improve the car park occupied slot counting system in two ways.

First, we can extend the number of slots to be examined to nine. We provide the modified Verilog description for the car park occupied slot counting system in Listing 8.30. We should form an IP block for this part to be used in the project.

Verilog Description of the Car Park Occupied Slot Counting System for Nine Cars code:3

Second, we can display the number of occupied slots on the rightmost seven-segment display of the Basys3 board. To do so, we should add the seven-segment display decoder module in code:4. Based on these modifications, the Verilog description of the top module for car park occupied slot counting system will be as in code:5.

Verilog Description of the Seven-Segment Display Decoder Module code:4

Improved Car Park Occupied Slot Counting System Implemented on the Basys3 Board in Verilog code:5

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