# CS201 Lab: Combinational Design

## Objective of this lab:

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To verify combinational design procedures by testing designed circuits.

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## Preparation

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Read lab lecture notes which contains the Combinational Design Procedure.

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## Lab Assignments

1. Design an elevator floor indicator:

Mr. Smith, multimillionaire lanlord, is renovating an eight story condo in downtown Regina. The building is epuiped with an ancient elevator that uses a mechanical system to indicate which floor it's currently on. He would like to add a simple indicator panel to the inside of the elevator that indicates the current floor by turning on one of the eight lights. Three switches attached to the exterior of the elevator will be used to encode the elevator's position in the lift way. Design a circuit to implement it in LogicWorks.

Hand-In

• The six steps used to solve this problem
• The circuits showing different floors

2. Design a circuit which will control LED segment "c" of a 7-Segment display.
• For example, for the numbers 0, 3, and 4, segment "c" should be lit;
for numbers 1, and 2, segment "c" should not be lit; etc.
• Design the circuit so that if someone applies a value from 10 to 15 then the LED segment does not light.

The following guidelines apply to the 2nd part of the lab assignment:

• You may only use NAND and NOT gates (it is common to have your design limited to certain gates).
• Show all the steps of the combinational design procedure including test results.
• Print out the circuit when inputs are 0, 1, 8, and 10.
• A 7-segment display can display the digits 0 - 9 by having the appropriate LEDs turned on.

Hand-In
• The six steps used to solve this problem
• Circuit testing 0, 1, 8, and 10

Copyright: Department of Computer Science, University of Regina.