Frederick University
Computer Engineering Faculty
Freshman Computer Engineering
(ACOE101)
Experiment #5
Logic Circuit Design
Student’s Name:
Semester:
Date:
Assessment:
Assessment Point
Weight
Methodology and correctness of results
Discussion of results
Participation
Assessment Points’ Grade:
Comments:
Grade
ACOE101: Freshman Computer Engineering
Experiment # 5
Experiment #5:
Logic Circuit Design
Objectives:
The objectives of this experiment are to show students:
1.
how to design a circuit using truth tables,
2.
how to simplify a digital circuit
Procedure:
Exercise 1:
(a)
Fill in the following Truth table. The output (X) should be one when there are
more ‘1’ than ‘0’
Table 1.
A
B
C
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
X
(b) Select the Logic Converter tool from the Instruments menu and place it in the
schematic area, as shown in Figure 1.
© Konstantinos Tatas
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ACOE101: Freshman Computer Engineering
Experiment # 5
Figure 1. Logic Converter
(c) Double-click on the Logic Converter icon and select the A, B and C inputs, as
shown in Figure 2.
© Konstantinos Tatas
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ACOE101: Freshman Computer Engineering
Experiment # 5
Figure 2. Input selection
(d) Copy the Table 1 output values to the Logic Converter truth table as shown in
Figure 3..
Figure 3. Truth table input
(e)
Select the Truth table to Logic expression conversion as shown in Figure 4.
Write down the expression shown.
© Konstantinos Tatas
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ACOE101: Freshman Computer Engineering
Experiment # 5
Figure 4. Truth table to logic expression conversion
(f)
Select the Truth table to circuit diagram conversion as shown in Figure 5. Note
the complexity of the derived circuit diagram, then delete it from the schematic
area.
Figure 5. Unsimplified circuit diagram
© Konstantinos Tatas
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ACOE101: Freshman Computer Engineering
Experiment # 5
(g) Select the truth table to simplified logic expression conversion as shown in Figure
6, and then select the expression to circuit diagram conversion. Note the much
simpler expression and circuit diagram.
Figure 6. Circuit diagram simplification
(h) Use a word generator and a logic analyzer, as in Laboratory exercise 4 to
confirm the truth table of the simplified logic diagram, as shown in Figure 7. Redraw
the simplified circuit if necessary.
© Konstantinos Tatas
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ACOE101: Freshman Computer Engineering
Experiment # 5
Figure 7. Simplified circuit simulation
Questions
1. Compare the unsimplified and simplified circuit in terms of number of gates.
© Konstantinos Tatas
Page 7