Revised 10/15/15
CENG 3112 Digital Circuits Lab
New Experiment 5: Example of Two-Level Design Using AND and OR Gates
Purpose: The purpose of this experiment is to understand and be able to implement two
level forms as well as gain experience in using Multisim.
Prelab: Find a circuit of AND and OR gates to realize f ( ABCD )   m(1,5,6,10,13,14)
1.
Draw the K-map for f. Write the summary of f in minterm form.
2.
Draw the 2 Level AND-OR gate circuit for f; compare with Figure 7-4.
3.
Use factoring or other technique to find a three-level OR AND-OR circuit; compare with Figure 7-5
4.
Using the K-map find an expression for f’ (hint what are the zeros of f?) Then find f; compare with equation 7-3.
5.
Find ( f’)’ =f ; compare with equation 7-4.
6.
Draw a two-level OR-AND circuit; compare with Figure 7.6.
7.
Partially multiply out the result to get a 3-level circuit –use (X+Y)((X + Z) = X + YZ.
8.
Draw the three-level AND –OR-AND circuit and compare with Figure 7-7.
Equipment:
Lab PC Running Multisim (for the simulations)
Laboratory Procedure:
Part 1. Simulation
Simulate each of the four circuits and verify the results.
Recall the 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 buffer to F (16 patterns will be generated.) . 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 l KHz 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.
Conclusion:
In you 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.