Basic Logic Circuits

Digital Logic for Computers

(ACOE161)

Experiment #3

Basic Logic Circuits

Student’s Name: Artem Plakhotnyuk	Reg. no.:7608
Semester: Spring 2015	Date: 14 November 2015

Assessment:

Assessment Point	Weight	Grade
Methodology and correctness of results
Discussion of results
Participation
Assessment Points’ Grade:

Comments:

Experiment #3:

Basic Logic Circuits

Objectives:

The objectives of this experiment are to:

1. Implement a logic function by building the logic circuit,

2. Analyze a logic circuit using a truth table, and

3. Investigate the concept that two or more circuits can result in exactly the same output.

Exercise 1:

(a) Derive the logic expression for the circuit illustrated in Figure 1.

Figure 1. Basic Logic Circuit with three inputs A, B, and C.

Logic Expression:

X = (((C’*B)+A)*C)+B

(b) Analyze the circuit in Figure 1 and complete Table 1 below.

Table 1. Basic Logic Circuit with three inputs A, B, and C.

A	B	C	C’	C’*B	(C’*B)+A	((C’*B)+A)*C)	X

(c) Use the breadboard in Figure 2 and mark using a blue colour pen all the necessary connections to build the circuit shown in Figure 1. Connect Input A on switch S1, Input B on switch S2, Input C on switch S3, and connect output X on LED 7.

	p0 p1 p2 p3 p0 p1 p2 p3

Figure 2. Breadboard diagram for Logic Function X.

(d) Turn off the Digital Trainer power. Place the ICs on the breadboard and make the connections shown in Figure 2. Turn on the Digital Trainer power.

(e) Go through all possible states of the switches S1, S2, and S3 and complete Table 2. Verify your results with Table 1.

Table 2. Basic Logic Circuit for Logic Function X.

S1/ P0	S2/ P1	S3/ P2	Output

Exercise 2:

(a) Draw the logic circuit in Figure 3 to implement the logic expression X = AC + B.

Circuit Diagram:

Figure 3. Basic Circuit of the logic expression X = AC + B.

(b) Use the breadboard in Figure 4 and mark using a red colour pen all the necessary connections to build the circuit illustrated in Figure 4. Connect Input A on switch S1, Input B on switch S2, Input C on switch S3, and connect output X on LED 7.

p0 p1 p2 p3 p0 p1 p2 p3  

Figure 4. Basic Circuit of the logic expression X = AC + B.

(c) Turn off the Digital Trainer power. Place the ICs on the breadboard and make the connections shown in Figure 4. Turn on the Digital Trainer power.

(d) Go through all possible states of the switches S1, S2, and S3 and complete Table 3. Compare your results with Table 2.

Table 3. Basic Logic Circuit for Logic Function X.

S1/ P0	S2/ P1	S3/ P2	Output

Questions:

1. Discuss the results of Exercise 1 (Table 1 and Table 2).

2. Discuss the results of Exercise 2 (Table 2 and Table 3).

3. Compare the circuits illustrated in Figure 2 and Figure 4 in terms of number of gates, number of IC, circuit complexity, power consumption and speed.

Дата добавления: 2015-11-14