Due date: October 25, 2001
Department of Computer
and
Mathematical Sciences
CS 3402
Digital Logic
Laboratory
8
Lab 8: Implementations of Multiplexers for a 2-Bit Adder
Objectives:
The goal for this lab is to design a circuit that two 2-bit binary numbers using different types of
multiplexers.
Background:
Any digital logic circuits can be implemented using multiplexers. One of the advantages of
using multiplexers is that we can design a circuit directly from the truth table. There are 7400
series multiplexers available in LogicWorksTM as follows:
74150 16-to-1 multiplexer (24 pins)
74151 8-to-1 multiplexer (16 pins)
74153 4-to-1 multiplexers
74157 2-to-1 multiplexers
The function of the 2-bit adder is to add a 2-bit binary number AB to a 2-bit binary number CD.
The result of the sum is a 3-bit binary number XYZ.
Task: 2-Bit Adders
Activity 1 Construct a truth table for a 2-bit adder that adds a 2-bit binary number AB to a 2-bit
binary number CD.
Activity 2 Use LogicWorksTM to construct the circuit diagrams from the truth table in Activity 1
by using three 74150, a hex display and a hex keyboard without strobe as input. Then test your
circuit and demonstrate your working circuit to the instructor. Illustrate the circuit diagram.
Activity 3 Use LogicWorksTM to construct the circuit diagrams from the truth table in Activity 1
by using six 74151, one 74157, a hex display and a hex keyboard without strobe as input. Then
test your circuit and demonstrate your working circuit to the instructor. Illustrate the circuit
diagram.
Activity 4 Use LogicWorksTM to construct the circuit diagrams from the truth table in Activity 1
by using three 74151, primitive gates, a hex display and a hex keyboard without strobe as input.
Then test your circuit and demonstrate your working circuit to the instructor. Illustrate the circuit
diagram.
Activity 5 Use LogicWorksTM to construct the circuit diagrams from the truth table in Activity 1
by using two 74153, primitive gates, a hex display and a hex keyboard without strobe as input.
Spring '1999, Lab 06,
2
Then test your circuit and demonstrate your working circuit to the instructor. Illustrate the circuit
diagram.