Revised 10/17/11/GCC
CENG 3112 .01 , .02.
Lab 6 Using Multiplexers to Implement a 2-bit Multiplier
Purpose:
The purpose of this experiment is to design and implement a circuit that will multiply two 2 -bit binary
numbers using Multiplexers and logic gates.
Prelab :
Draw the truth table for the Multiplier having A , B , C and D as inputs and W, X ,Y and Z as outputs.
AB
* CD
WXYZ
Design a circuit to implement the truth table using Multiplexers (74151) and logic gates .
Using a TTL data book, find the integrated circuit part numbers that will allow you to implement these
functions. Also read the truth table related to 74151 to learn more about the chip.
When you realize these circuits at the same time what do you expect the result to be? Verify your answer
using truth tables.
In your lab books write as an assignment the VHDL code that will do the same thing . You do not have to
simulate this VHDL code until experiment 7.
Laboratory Procedure:
Part 1. Simulation
Using Multisim construct a circuit that consists of the word generator and the logic analyzer. You will
find these under the "Instruments" button.
1A.Set up:
Word generator:
Set the word generator to internal clocking with the frequency of 1 KHz. Select an initial address of 0000
and set the final address to 000F. Set the pattern to count up. This will generate a timing diagram that shows
all possible combinations of the inputs.
Logic analyzer:
Set the logic analyzer to internal clocking with the frequency of lKHz and set the clocks per division to 2.
Connect the outputs of the word generator to the logic analyzer and run the simulation. Verify that the output
is that of a mod 16 counter.
Implement the circuits that you designed in the Prelab section. (Note: The output of each two level form is
connected to the logic analyzer.) Run the simulation and print the logic analyzer output and put it in your lab
book.
Part 2. Prototyping
Implement the circuits using theNi Elvis trainer and the components in the lab kits. Have a teaching assistant
initial your lab book when you have demonstrated a working circuit.
Conclusion:
In your lab book, discuss your observations and conclusions and briefly explain whether circuit simulation or
actually constructing the circuit is more supportive of your learning and understanding the material.