# Lab #4 Solution

\$30.00 \$24.90

## Description

• Preparation

1. Read this document in its entirety.

1. Have the following circuit diagrams (or corresponding Verilog code) and truth tables ready on paper

1. 3 8 decoder

1. 3-bit majority function

1. Voting System for Miniature University (you don’t need to prepare a truth table for this one)

2 3 8 Decoder

Inside your ECE2700 directory, create a new folder called Lab4. Start up Xilinx and create a new project called Comb inside the Lab4 directory.

Create a new le called dec3x8.v. Inside, design a 3 8 decoder. Use the following declaration: dec3x8(i2, i1, i0, d7, d6, d5, d4, d3, d2, d1, d0), where ix are the inputs and dx are the out-puts (i2 is the most signi cant input bit and d7 is the most signi cant output bit).

Exhaustively test your design and show the results to the TA.

3 3-Bit Majority Function

Inside a new le called maj.v, design a 3-bit majority function. As its name implies, a majority function outputs (returns) 1 if more than half of the inputs are 1 (in our case, 2 or more input bits are 1). The inputs are a; b; and c. The output is F . You are required to design this function using the 3 8 decoder you designed earlier.

Exhaustively test your design and show the results to the TA.

4 Voting System for Miniature University

You are asked to design a voting system for Miniature University. The university has 3 students, 1 teacher, and 1 president. In this voting system, all the students get 1 vote collectively while both professor and president each get one vote. Design your system in a le called voting.v using instances of the 3-bit majority function constructed earlier. The inputs to the system are s2, s1, s0, t, and p, where sx are students’ votes, t is the teacher’s vote, and p is the president’s vote. The output is G.

1

Test your design. Since there are many test cases, you do not need to exhaustively test your system. However, select no fewer than 10 test cases and show the results to the TA. You are responsible for convincing the TA that your design is correct.

Implement your design on the Basys board. You have the freedom to assign pins as you see t.

• TA Checko

(10 points) Prelab design (20 points) 3 8 decoder

(20 points) Majority function (50 points) Voting system

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