B T L INSTITUTE OF TECHNOLOGY & MANAGEMENT No.259/B, Hosur Road, Boomasandhra, Bangalore- 560 099
A LAB MANUAL ON
LOGIC DESIGN Subject Code: 10ESL38 (As per VTU Syllabus)
PREPARED BY
Staff Members - Dept. of ECE
Logic Design Lab
10ESL38
TABLE OF CONTENTS Experiments
Page No.
IC Pin Configurations
2
1.
Boolean Expression realization using Logic gates
4
2.
Half/Full Adder and Subtractor
7
3.
a. Parallel Adder/ Subtractor
10
b. BCD to Excess-3 and Vice-versa
14
4.
Binary to Gray Conversion and vice versa
16
5.
MUX/DEMUX for arithmetic circuits
21
6.
Comparators
27
7.
Decoder Chip for LED Display
31
8.
Priority Encoder
33
9.
Flip-Flop verification
35
10. Counters
38
11. Shift Registers
50
12. Ring Counter/ Johnson Counter
55
13. Sequence Generator
57
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Logic Design Lab Syllabus – 10ESL38
59
Possible Viva Questions
60
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Logic Design Lab
10ESL38
IC Pin configurations Inverter (NOT Gate) - 7404LS
2-Input AND Gate - 7408LS
2-Input OR Gate - 7432LS
2-Input NAND Gate - 7400LS
2-Input NOR Gate - 7402LS
2-Input EX-OR Gate - 7486LS
3-Input NAND Gate - 7410LS
Dept. of ECE
4-bit Binary Full Adder74LS83
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Logic Design Lab
10ESL38
Dual 4-Input NAND Gate - 7420LS
Dual 4-input Multiplexer74153
4-Bit Magnitude Comparator - 7485
Decoders/Demultiplexer 74139
Shift Register - 7495
Synchronous Up/Down Counter– 74192
Decimal scalar - 7490
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DualJK Flip-flop– 7476
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Logic Design Lab
10ESL38
Experiment No. 1
BOOLEAN EXPRESSION REALIZATION USING LOGIC GATES Aim: – To Simplify and Realize Boolean expressions using logic gates/Universal gates. Components Required: -
IC 7408 (AND), IC 7404 (NOT), IC 7432 (OR),IC 7400 (NAND), IC 7402 (NOR),IC 7486 (EX-OR)
Procedure – 1. Verify that the gates are working. 2. Construct a truth table for the given problem. 3. Draw a Karnaugh Map corresponding to the given truth table. 4. Simplify the given Boolean expression manually using the Karnaugh Map. A: Implementation Using Logic Gates 5. Realize the simplified expression using logic gates. 6. Connect VCC and ground as shown in the pin diagram. 7. Make connections as per the logic gate diagram. 8. Apply the different combinations of input according to the truth tables. 9. Check the output readings for the given circuits; check them against the truth tables. 10. Verify that the results are correct. B. Implementation Using Universal Gates 11. Convert the AND-OR logic into NAND-NAND and NOR-NOR logic. 12. Implement the simplified Boolean expressions using only NAND gates, and then using only NOR gates. 13. Connect the circuits according to the circuit diagrams, apply inputs according to the truth table and verify the results.
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Logic Design Lab
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Given Problem:
Truth Table: A 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
B 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
C 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
D 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
Y 0 0 0 0 0 1 1 1 0 0 0 0 0 1 1 1
Switching Expression:
∑
π Karnaugh Map Simplification: K-Map for SOP
K-Map for POS
CD AB
CD
00
01 1 1 1
00 01 11 10
11
10
1 1
1 1
AB 00 01 11 10
BC
BD
00 0 0 0 0
01 0
11 0
10 0 B
0
0
0
C+D
Simplified Boolean Expression: SOP form Y=f(A,B,C,D)=BC+BD POS form Y=f(A,B,C,D)=B(C+D)
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Logic Design Lab
Dept of ECE
10ESL38
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Expression Realization using Basic Gates: C
1
3
7408
1
2
B
3
7432 4 7408
D
2
6
Y=BC+BD
5
B C D
1 7432
Y = B(C+D)
3
7408
1
2
3
2
Realization using only NAND gates:
C
1 7400
3 7400
4
D
2
B
9
2
B
Realization using only NOR gates:
8
7402
Y = BC+ B D
10 7400
C
6
D
5
2 7402
1
B
5
5 7402
7402'
4 2
7402
10
7402'
10
7402 9
Y = BC+BD
9
1
7402'
8
8
4
6
3
9
Realization using only NAND gates: B C
11 7400
1 7400
3
2
D
9 7400 10
4 7400 5
12
6
8
13
1 7400' 2
3
7402
8
13
12
6
D
11 7402
3
5 6
Realization using only NOR gates: C
1
3
Y = B(C +D)
10
4
Y = B(C + D )
Experiment No. 2
HALF/FULL ADDER AND HALF/FULL SUBTRACTOR Aim: – To realize half/full adder and half/full subtractor using Logic gates Components Required: -
IC 7408, IC 7432, IC 7486, IC 7404, etc.
Procedure: 1. Verify that the gates are working. 2. Make the connections as per the circuit diagram for the half adder circuit, on the trainer kit. 3. Switch on the VCC power supply and apply the various combinations of the inputs according to the respective truth tables. 4. Note down the output readings for the half adder circuit for the corresponding combination of inputs. 5. Verify that the outputs are according to the expected results. 6. Repeat the procedure for the full adder circuit, the half subtractor and full subtractor circuits. 7. Verify that the sum/difference and carry/borrow bits are according to the expected values.
A. Half Adder using Logic Gates: Half Adder Using Basic Gates
1
A B
7486 2 1 7408
A
B
S
C
0
0
0
0
0
1
1
0
1
0
1
0
1
1
0
1
3
3
2
B. Full Adder Using Logic Gates
Full Adder Using Basic Gates A
B
Cn-1
S
C
0
0
0
0
0
0
0
1
1
0
0
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
0
1
0
1
1
1
0
0
1
1
1
1
1
1
C. Half Subtractor Using Logic Gates Half Subtractor Using Basic Gates
C
A
B
D
B
0
0
0
0
0
1
1
1
1
0
1
0
1
1
0
0
D. Full Subtractor Using Logic Gates
Full Subtractor Using Basic Gates A
B
Cn-1
D
B
0
0
0
0
0
0
0
1
1
1
0
1
0
1
1
0
1
1
0
1
1
0
0
1
0
1
0
1
0
0
1
1
0
0
0
1
1
1
1
1
Experiment No. 3
PARALLEL ADDER AND SUBTRACTOR USING 7483 Aim: –i. To realize Parallel Adder and Subtractor Circuits using IC 7483 ii. BCD to Excess-3 Code conversion and Vice Versa using IC7483 Components Required: -
IC 7483, IC 7486, etc.
Procedure: 1. Connect one set of inputs from A1 to A4 pins and the other set from B1 to B4, on the IC 7483. 2.Connect the pins from S1 to S4 to output terminals. 3. Short S,C0 to XOR gate 1 input and other input take from C4 and obtain the Output Carry Cout (Output Borrow Bout). 4. In order to Perform Addition take S=0. 5. In order to implement the IC 7483 as a subtractor, Take S=1, Apply the B input through XOR gates (essentially taking complement of B). 6. Apply the inputs to the adder/ subtractor circuits as shown in the truth tables. 7. Check the outputs and note them down in the table for the corresponding inputs. 8. Verify that the outputs match with the expected results. IC 7483 Pin Diagram
7483
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A. IC 7483 as a Parallel Adder Circuit Diagram: Output Carry
VCC 5
A4 1
A3
Input Data A
14
3
A2
8
A1
15
10
2 6
1
7486
B4
1
3
16
9
C4
7486'
3
Cout
2
S4 S3
Data Output
S2 S1
2 4
7486
6
7483
4
5
Input Data B
B3
9
7486 10 12
B2
7486
8
7
11
11
13
1
13
B1
12 GND
C0
S= 0
Truth Table:-
4-BITParallel Adder Using 7483 where S=0
Input Data A
Input Data B
Addition
A4
A3
A2
A1
B4
B3
B2
B1
Cout
S4
S3
S2
S1
1
0
0
0
0
0
1
0
0
1
0
1
0
1
0
0
0
1
0
0
0
1
0
0
0
0
0
0
1
0
1
0
0
0
0
1
0
1
0
0
0
0
1
0
1
1
1
0
1
0
0
0
1
0
1
0
1
0
1
1
1
0
1
0
1
0
1
1
0
0
0
1
1
0
1
0
0
1
1
1
1
0
1
1
1
1
1
1
1
0
1
1
0
1
0
1
1
0
1
1
0
1
1
1
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B. IC 7483 as a Parallel Subtractor
5
A4 A3
Input Data A
A2 A1 1
B4
7486
B1
14
3 8
15
10
3
16
6
9
7486'
7486 10 12
7486
8
1
11
S3 S2 S1
11
C0
12 GND
4-BITParallel Subtractor Using 7483 Where S=1 Truth Table:
Bout
S4
7
13
3
2
7483
4
13
S= 1
2
C4
5 9
B2
1
2
7486 B3
1
6
4
Input Data B
Output Carry
VCC
Circuit Diagram:
Data Output
Subtraction Input Data A A4
A3
A2
Input Data B A1
Note: Bout = 1 for A
B4
B3
B2
Bout = 0 for A>B; 0 0 1
B1
Bout
S4
S3
S2
S1
0
0
0
1
1
0
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
1
1
0
1
0
0
0
0
1
0
1
1
1
1
1
0
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
0
1
1
0
0
0
1
1
0
0
0
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
1
0
1
1
0
1
1
1
1
0
1
Example 4bit adder operation using 7483 if control input S=0,addition can be performed Ex: If ↓C0=0 A4 A3 A2 A1=1100 B4 B3 B2 B1=0011
then Sum,S4 S3 S2 S1 =1111 and C0 C4 = Cout. 4 bit subtraction operation using 7483 for A>B here S=1 A4 A3 A2 A1= 1001 B4 B3 B2 B1= 1101 (2's complement) of +3=0011 1 0110 The end around carry is disregarded C0 C4 = Bout = 0 Difference, S4 S3 S2 S1 = 0110 2's complement method of subtraction can be performed, if S=1(i.e. C0=1). Consider the above Example A4 A_3 A2_A_1= 1_001 and B4 B3 B2 B1= 0011 1‟s C omp lemen t o f B4 B3 B2 B1 is B4 B3 B2 B1= 1100
.
_A4 A_3 A_2 A_1= B4 B3 B2 B1=
The end around carry is disregarded
1001
1100 → (1's complement) of +3 = 0011 + 1 ← C0=1(S&C0 shorted)
2‟ sComp leme n t of B input = -B
1 0110
C0 C4 = Bout = 0
+6
4 bit subtraction operation using 7483 for A
_A4 A_3 A_2 A_1= 1110 B4 B3 B2 B1=
0000 → (1's complement) of +15 = 1111 +1 ← C0=1(S&C0 shorted)
The end around carry is disregarded
0 1111 → (2's complement) of +1 = 0001
C0 C4 = Bout = 1 -1
2‟ sComp leme n t of B input = -B
C. BCD To Excess-3 And Vice-Versa Conversion Using 7483 Chip I.
BCD TO EXCESS-3 CONVERTER
Note: S = 0 and B3,B2,B1,B0 = 0011 vary the BCD input at A3,A2,A1,A0. VCC
Circuit Diagram: A3 A2
Input Data A
A1 A0 1
7486
B3 = 0
Input Data B
5
1
C4
14
3 8
E3
15
10
E2
2
E1
6
3
16
X NC
E0
9
Data Output
2
4
B2 = 0
7486
6
7486
8
7486
11
7483
4
5 9 10 12
B1 = 1
1
7 11
13
13 12
B0 = 1
GND
C0
S= 0 BC Dto X C S3using 7483
Truth Table :
Consider Constant Value for B3B2B1B0 = 0011 and S=0 BCD Inputs
Excess – 3 Outputs
A3
A2
A1
A0
E3
E2
E1
E0
0
0
0
0
0
0
1
1
0 0 0 0 0 0 0 1 1 1 1 1 1 1
0 0 0 1 1 1 1 0 0 0 0 1 1 1
0 1 1 0 0 1 1 0 0 1 1 0 0 1
1 0 1 0 1 0 1 0 1 0 1 0 1 0
0 0 0 0 1 1 1 1 1 X X X X X
1 1 1 1 0 0 0 0 1 X X X X X
0 0 1 1 0 0 1 1 0 X X X X X
0 1 0 1 0 1 0 1 0 X X X X X
1
1
1
1
X
X
X
X
II.
EXCESS-3 to BCD CONVERTER
Note: S=1 and B3,B2,B1,B0 = 0011 vary the Excess-3 input at A3(E3),A2(E2),A1(E1),A0(E0).
Circuit Diagram:
VCC
A3 A2
Input Data A
8
A0
B3 = 0
B
B2 = 0
C4
10
7486
3
C
2
16
7486
6
7486
8
7486
11
X NC
D
15
B
6
2 4
Input Data
14
3
A1
1
5
1
A
9
Data Output
7483
4
5 9
B1 = 1
10 12
B0 = 1
7 11
13
12
13
GND
C0
S=1
Truth Table :
X CS3to BCDusing 7483
Consider Constant Value for B3B2B1B0 = 0011 and S=1 Excess-3 Inputs
BCD Outputs
E3
E2
E1
E0
A
B
C
D
0
0
1
1
0
0
0
0
0
1
0
0
0
0
0
1
0
1
0
1
0
0
1
0
0
1
1
0
0
0
1
1
0
1
1
1
0
1
0
0
1
0
0
0
0
1
0
1
1
0
0
1
0
1
1
0
1
0
1
0
0
1
1
1
1
0
1
1
1
0
0
0
1
1
0
0
1
0
0
1
Experiment No. 4
BINARY TO GRAY CONVERTER AND VICE VERSA Aim: – To realize:. i. Binary to Gray Converter using logic gates. ii. Gray to Binary Converter using logic gates. Components Required: -
IC 7486, etc.
Procedure: 1.Verify that the gates are working properly. 2. Write the proper truth table for the given Binary to Gray converter. 3. Draw Karnaugh maps for each bit of output. Simplify the Karnaugh maps to get simplified Boolean Expressions. 4. Make connections on the trainer kit as shown in the circuit diagram for the Binary to Gray converter. 5. Apply the Binary inputs at B3-B0 pins, according to the truth table. 6. Check the outputs at the G3-G0 pins and note them down in the table for the corresponding inputs. 7. Verify that the outputs match with the expected results. 8. Repeat the procedure to design, test and verify the working of a Grey to Binary Converter.
A. Binary to Gray Converter. Truth Table: Binary Input
Gray Code Output
B3
B2
B1
B0
G3
G2
G1
G0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
1
0
0
0
1
1
0
0
1
1
0
0
1
0
0
1
0
0
0
1
1
0
0
1
0
1
0
1
1
1
0
1
1
0
0
1
0
1
0
1
1
1
0
1
0
0
1
0
0
0
1
1
0
0
1
0
0
1
1
1
0
1
1
0
1
0
1
1
1
1
1
0
1
1
1
1
1
0
1
1
0
0
1
0
1
0
1
1
0
1
1
0
1
1
1
1
1
0
1
0
0
1
1
1
1
1
1
0
0
0
Karnaugh Maps: For G3:
G3 = B 3
For G2:
For G1:
Circuit:
For G0:
B. Gray to Binary Converter Truth Table Gray Code Input
Binary Output
G3
G2
G1
G0
B3
B2
B1
B0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
1
1
0
0
1
0
0
0
1
0
0
0
1
1
0
1
1
0
0
1
0
0
0
1
1
1
0
1
0
1
0
1
0
1
0
1
1
0
0
1
0
0
0
1
1
1
1
1
0
0
1
0
0
0
1
1
0
1
1
0
0
1
1
1
1
1
1
0
1
0
1
1
1
0
1
0
1
1
1
0
1
0
1
1
0
0
1
0
1
1
1
1
0
1
1
0
0
1
1
1
1
0
1
0
0
0
1
1
1
1
Karnaugh Maps:
For B3:
B3 = G3
For B2:
For B1:
Circuit:
For B0:
Experiment No. 5
MUX/DEMUX FOR ARITHMETIC CIRCUITS Aim: – To study IC 74153 and 74139 and to implement arithmetic circuits with them. Components Required: -
IC 74153, IC 74139, IC 7404, IC 7400, IC 7420,etc.
Procedure – A. For MUX IC 74153 1.The Pin [16] is connectedto + V cc and Pin [8] is co nnectedto ground. 2. The inputs are a pplied either to ‘A ’ input or ‘B’ input. 3.If MUX ‘A ’ has to b e initialized, EA is m adelow and if MUX ‘B’ has to b e initialized, EB is m adelow. 4. Based on the selection lines one of the inputs wi ll be selected at the output, and thus the truth table is verified. 5.In case of half adder using MUX, apply constant inputs at (I0a, I1a, I2a, I3a)and (I0b, I1b, I2b and I3b) as shown. 6.The corresponding values of select input lines, A and B (S1 and S0) are ch anged as per table and the output is taken at Za as sum and Zb as carry. 7.In this case, the inputs A and B are varied. Making Ea and Eb zero andthe output is taken at Za, and Zb. 8.In caseof Half Subtractor, connections are m ade acc ording to the circuit, Inputs are applied at A and B as shown, and outputs are taken at Za (Differe n ce) and Zb (Borrow). Veri fy outputs. 9.In full adder using MUX, the inputs are applied at Cn-1, An and Bn according to the truth table. The corresponding outputs are taken at Sn (pin Za) and Cn (pin Zb) and are verified according to the truth table. 10. In full subtractor using MUX, the inputs are applied at Cn-1, An and Bn according to the truth
table. The corresponding outputs are
taken at pin Za(Difference) and pin Zb(Borrow) and are verified according to the truth table.
Half Adder Using 74153
Half Subtractor using 74153
Truth Table: Inputs
Half Adder Outputs
Half Subtractor Outputs
A
B
Sum
Carry
Diff
Borrow
0
0
0
0
0
0
0
1
1
0
1
1
1
0
1
0
1
0
1
1
0
1
0
0
Full Adder Using 74153
Full Subtractor using 74153
Truth Tables for Full Adder/Subtractor using 74153 Inputs
Full Adder Outputs
A
B
Cin/Bin
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Full Subtractor Outputs
S
Cout
D
Bout
0
0
0
0
1
0
1
1
1
0
1
1
0
1
0
1
1
0
1
0
0
1
0
0
0
1
0
0
1
1
1
1
Procedure – B. For DEMUX IC 74139 1. The Pin [16] is co nnectedto + Vcc and Pin [8] is connectedto ground. 2. The inputs are applied either to ‘A’ input or ‘B’ input. 3. If DEMUX ‘A ’ has to b e initialized, EA is m ade low and if DEMUX ‘B’ has to b e initialized, EB is m adelow. 4. Based on the selection lines one of the inputs will be selected at the set of outputs, and thus the truth table is verified. 5. In ca se of half adder using DEMUX ,Ea is set to 0, the corresponding values of select input lines, A and B (S1a and S0a) are changedas per table andthe output is taken at Sum and Carry. Verify outputs. 6. In ca se of Half Subtractor, connections are m ade according to the circuit, Inputs are applied at A and B as shown, and outputs are taken at Differencea n dBorrow. Verify outputs. 7. In full adder using DEMUX, the inputs are applied at Cn-1, An and Bn according to the truth table. The corresponding outputs are taken at Sum and Carry, and are verified a ccording to the truth table. 8. In full subtractor using DEMUX, the inputs are applied at Cn-1, An and Bn according to the truth table. The corresponding outputs are taken at Differenc e and Borrow as shown, and are verified according to the truth table.
Half Adder Using 74139
Half Subtractor Using 74139
Truth Tables: Inputs
Half Adder Outputs
Half Subtractor Outputs
A
B
Sum
Carry
Diff
Borrow
0
0
0
0
0
0
0
1
1
0
1
1
1
0
1
0
1
0
1
1
0
1
0
0
Full Adder Using 74139
Full Subtractor Using 74139
Truth Tables: Inputs
Full Adder Outputs
A
B
Cin/Bin
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Full Subtractor Outputs
S
Cout
D
Bout
0
0
0
0
1
0
1
1
1
0
1
1
0
1
0
1
1
0
1
0
0
1
0
0
0
1
0
0
1
1
1
1
Experiment No. 6
ONE/TWO BITCOMPARATOR AND IC 7485 Aim: – To verify the truth tables for one bit and two bit comparators after constructing them with basic logic gates, and to study the working of IC 7485. Components Required: -
IC 7404, IC 7408, IC 7486, IC 7432, IC 7485, etc.
Procedure – A. Comparators Using Logic Gates: 1.Verify the working of the logic gates. 2.Make the connections as per the respective circuit diagrams. 3.Switch on Vcc. 4.Apply the inputs as per the truth tables. 5.Check the outputs and verify that they are according to the truth tables. B. Study of IC 7485: 1.Write the truth table for an4-bit comparator. 2. Connect pin 16 to Vcc and pin 8 to GND for the ICs. 3.Apply the two inputs as shown; making sure that the MSB and LSB is correctly connected. 4. Outputs are recorded at pin 2 (AB), pin 3 (A=B) pins and are verified as being according to the truth table. A. One-Bit Comparator: Circuit :
Truth Table: 1bit Comparator Inputs
B. Two-Bit Comparator:
Outputs
A
B
A>B
A=B
A
0
0
0
1
0
0
1
0
0
1
1
0
1
0
0
1
1
0
1
0
Truth Table : 2bit Comparator A1 A0 B1 B0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
A>B
A=B
A
0 0 0 0 1 0 0 0 1 1 0 0 1 1 1 0
1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1
0 1 1 1 0 0 1 1 0 0 0 1 0 0 0 0
Karnaugh Maps: For A>B:
For A=B
For A
Circuit:
C. 4-Bit comparator using IC 7485 Pin Diagram:
Truth Table: 4bit Comparator Input A
Input B
Output
A3
A2
A1
A0
B3
B2
B1
B0
A>B
A
A=B
0
0
0
0
0
0
0
1
0
1
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
0
1
0
1
0
0
0
1
0
0
1
1
0
1
1
0
0
1
0
0
1
0
0
1
0
0
0
0
1
0
1
1
0
1
1
0
1
1
1
0
0
0
1
1
0
0
1
1
0
0
0
1
1
1
1
1
1
1
1
0
1
0
0
Experiment No. 7
DECODER CHIP FOR LED DISPLAY Aim: – Tostudy the use of a Decoder Chip (IC 7447) to drive a LED Display. Components required: -
IC 7447, 7-segment LED Display, etc.
Procedure: 1. Test and verify that all the segments of the LED Display are working. 2. Make the circuit connections as shown in the circuit diagram. 3. Connect Pin 16 to Vcc and Pin 8 to GND. 4. Connect the input pinsof the 7-segment LED Display to the respective pins (A3-A0) of the 7447 BCD to 7-Segment decoder driver chip. 5. Give the different BCD inputs according to the truth table, and observe the Decimal outputs displayed on the 7-segment LCD Display. 6. Verify that the outputs match the expected results in the truth tables.
IC 7447 Pin Diagram
Circuit Diagram:
Output Table: BCD inputs segment outputs display D C B A a b c d e f g 0 0 0 0 1 1 1 1 1 1 0 0
0
0
1
0 1 1 0 0 0 0
0
0
1
0
1 1 0 1 1 0 1
0
0
1
1
1 1 1 1 0 0 1
0
1
0
0
0 1 1 0 0 1 1
0
1
0
1
1 0 1 1 0 1 1
0
1
1
0
0 0 1 1 1 1 1
0
1
1
1
1 1 1 0 0 0 0
1
0
0
0
1 1 1 1 1 1 1
1
0
0
1
1 1 1 0 0 1 1
7-segment LED Display Schematic
Experiment No. 8
PRIORITY ENCODER Aim: – Tostudy the use of a 10-line-to-4-Line Priority Encoder Chip (IC 74147). Components Required: -
IC 74147, etc.
Procedure: 1. Make the connections as shown in the circuit diagram. 2. Connect Pin 16 of the IC to Vcc and Pin 8 to GND. 3. Connect the pins designated Inputs 1 through 9, to the input switches of the trainer kit. 4. Connect the Output pins designated A, B, C, D to the LED indicators of the trainer kit. 5. Provide the inputs to the encoder chip as shown in the truth table. 6. Observe the outputs on the LED indicators, and note down the results for the respective inputs. 7. Verify that the outputs are as shown in the truth table.
IC 74147 Pin Diagram
Truth Table:
1 1 0 X X X X X X X X
2 1 1 0 X X X X X X X
3 1 1 1 0 X X X X X X
Decimal Input 4 5 6 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 X 0 1 X X 0 X X X X X X X X X
7 1 1 1 1 1 1 1 0 X X
8 1 1 1 1 1 1 1 1 0 X
9 1 1 1 1 1 1 1 1 1 0
BCD Output D C B A 1 1 1 1 1 1 1 0 1 1 0 1 1 1 0 0 1 0 1 1 1 0 1 0 1 0 0 1 1 0 0 0 0 1 1 1 0 1 1 0
Decimal Value 0 1 2 3 4 5 6 7 8 9
Experiment No. 9
STUDY OF FLIP-FLOPS Aim: – To study and verify the truth tables for J-K Master Slave Flip Flop, T-type and DType Flip-Flops. Components Required: -
IC 7410, IC 7400, etc.
Procedure: 1. Make the connections as shown in the respective circuit diagrams. 2. Apply inputs as shown in the respective truth tables, for each of the flip-flop circuits. 3. Check the outputs of the circuits; verify that they match that of the respective truth tables. A. J-K Master-Slave Flip-Flop Circuit:
Truth Table : Preset
Clear
J
K
Clock
Status
0
1
X
X
X
1
0
Set
1
0
X
X
X
0
1
Reset
1
1
0
0
1
1
0
1
0
1
Reset
1
1
1
0
1
0
Set
1
1
1
1
No Change
Toggle
B. T-Type Flip-Flop Circuit:
Truth Table : Preset
Clear
T
1
1
0
1
1
1
Clock
C. D-Type Flip-Flop Circuit:
Truth Table: Preset
Clear
D
Clock
1
1
0
0
1
1
1
1
1
0
Experiment No. 10
STUDY OF COUNTERS Aim: – Realization of 3-bit counters as a sequential circuit and Mod-N counter Design (7476, 7490, 74192, 74193) Components Required: -
IC 7476, IC 7490, IC 74192, IC 74193, IC 7400, IC 7408, IC 7416, IC 7432, etc.
Procedure: A. Counter Circuits using IC 7476 1. Make the connections as shown in the respective circuit diagrams. 2. Clock inputs are applied one by one at the clock I/P, and the outputs are observed at QA, QB and QC pins of the 7476 ICs. 3. Verify that the circuit outputs match those indicated by the truth tables. B. Study of Counters IC 74192, IC 74193 1. Connections are made as shown in the respective circuit diagrams, except for the connection from the output of the NAND gate to the load input. 2. The data (0011) = 3 is made available at the data input pins designated A, B, C and D respectively. 3. The Load pin is made LOW so that the data 0011 appears at QD, QC, QB and QA respectively. 4. Now, the output of the NAND gate is connected to the Load input pin. 5. C lo ck p u lses are a p p liedto th e “Coun t Up” p in ,a n dtru thta b leis ve rifie d for that condition. 6. Next, the data (1100) =12 (for 12 to 5 counter) is applied at A, B, C and D and the same procedure as explained above, is performed. 7. IC 74192 and IC 74193 have the same pin configurations. 74192 can be configured to count between 0 and 9 in either direction. Starting value can be any number between 0 and 9.
A. 3-bit Asynchronous Up Counter Circuit Diagram:
Timing Diagram:
Truth Table: Clock
QC
QB
QA
0
0
0
0
1
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5
1
0
1
6
1
1
0
7
1
1
1
8
0
0
0
9
0
0
1
B. 3-bit Asynchronous Down Counter Circuit Diagram:
Timing Diagram:
Truth Table:
Dept. Of ECE.
Clock
QC
QB
QA
0
1
1
1
1
1
1
0
2
1
0
1
3
1
0
0
4
0
1
1
5
0
1
0
6
0
0
1
7
0
0
0
8
1
1
1
9
1
1
0
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BTLInstitute of Technology & Management
C. Mod-5 Asynchronous Counter Circuit:
Timing Diagram:
Truth Table:
Dept. Of ECE.
Clock
QC
QB
QA
0
0
0
0
1
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5
0
0
0
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BTLInstitute of Technology & Management
D. Mod-3 Asynchronous Counter Circuit:
Timing Diagram:
Truth Table:
Dept. Of ECE.
Clock
QC
QB
QA
0
0
0
0
1
0
0
1
2
0
1
0
3
0
0
0
4
0
0
1
5
0
1
0
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E. 3-bit Synchronous Counter Circuit:
Timing Diagram:
Truth Table:
Dept. Of ECE.
Clock
QC
QB
QA
0
0
0
0
1
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5
1
0
1
6
1
1
0
7
1
1
1
8
0
0
0
9
0
0
1
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F. 4-bit Ripple Counter Circuit:
Truth Table:
Dept. Of ECE.
CLK
QD
QC
QB
QA
0
0
0
0
0
1
0
0
0
1
2
0
0
1
0
3
0
0
1
1
4
0
1
0
0
5
0
1
0
1
6
0
1
1
0
7
0
1
1
1
8
1
0
0
0
9
1
0
0
1
10
1
0
1
0
11
1
0
1
1
12
1
1
0
0
13
1
1
0
1
14
1
1
1
0
15
1
1
1
1
44
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G. Mod-10 Ripple Counter Circuit:
Truth Table
Dept. Of ECE.
CLK
QD
QC
QB
QA
0
0
0
0
0
1
0
0
0
1
2
0
0
1
0
3
0
0
1
1
4
0
1
0
0
5
0
1
0
1
6
0
1
1
0
7
0
1
1
1
8
1
0
0
0
9
1
0
0
1
10
0
0
0
0
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H. Decade Counter (using IC 7490) Circuit:
Truth Table:
Dept. Of ECE.
Clock
QD
QC
QB
QA
0
0
0
0
0
1
0
0
0
1
2
0
0
1
0
3
0
0
1
1
4
0
1
0
0
5
0
1
0
1
6
0
1
1
0
7
0
1
1
1
8
1
0
0
0
9
1
0
0
1
10
0
0
0
0
46
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I. Mod-8 Counter (Using IC 7490) Circuit:
Truth Table:
Dept. Of ECE.
Clock
QD
QC
QB
QA
0
0
0
0
0
1
0
0
0
1
2
0
0
1
0
3
0
0
1
1
4
0
1
0
0
5
0
1
0
1
6
0
1
1
0
7
0
1
1
1
8
0
0
0
0
9
0
0
0
1
47
BTLInstitute of Technology & Management
J. Presettable counter using IC 74192/IC 74193 to count up from 3 to 8 Circuit:
Truth Table: Clock
QD
QC
QB
QA
Decimal
0
0
0
1
1
3
1
0
1
0
0
4
2
0
1
0
1
5
3
0
1
1
0
6
4
0
1
1
1
7
5
1
0
0
0
8
6
0
0
1
1
3
7
0
1
0
0
4
Dept. Of ECE.
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K. Presettable counter using IC 74192/74193 to count down from 5 to 12 Circuit:
Implementation of 4-Input OR gate:
Truth Table:
Dept. Of ECE.
Clock
QD
QC
QB
QA
Decimal
0
0
1
0
1
5
1
0
1
1
0
6
2
0
1
1
1
7
3
1
0
0
0
8
4
1
0
0
1
9
5
1
0
1
0
10
6
1
0
1
1
11
7
1
1
0
0
12
8
0
1
0
1
5
9
0
1
1
0
6
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Experiment No. 11
STUDY OF SHIFT REGISTERS Aim: – To study IC 74S95, and the realization of Shift left, Shift right, SIPO, SISO, PISO, PIPO operations using the same. Components Required: -
IC 7495, etc.
Procedure: A. Serial In-Parallel Out (Left Shift): 1. Make the connections as shown in the respective circuit diagram. 2. Make sure the 7495 is operating in Parallel mode by ensuring Pin 6 (Mode M) is set to HIGH, and connect clock input to Pin 8 (Clk 2). 3. Apply the first data at pin 5 (D) and apply one clock pulse. We observe that this data appears at pin 10 (QD). 4. Now, apply the second data at D. Apply a clock pulse. We now observe that the earlier data is shifted from QD to QC, and the new data appears at QD. 5. Repeat the earlier step to enter data, until all bits are entered one by one. th
6. At the end of the 4 clock pulse, we notice that all 4 bits are available at the parallel output pins QA (MSB), QB, QC, QD (LSB). 7. Enter more bits to see there is a left shifting of bits with each succeeding clock pulse. B. Serial In-Parallel Out (Right Shift): 1. Make the connections as shown in the respective circuit diagram. 2. Make sure the 7495 is operating in SIPO mode by ensuring Pin 6 (Mode M) is set to LOW, and connect clock input to Pin 9 (Clk 1). 3. Apply the first data at pin 1 (SD1) and apply one clock pulse. We observe that this data appears at pin 13 (QA). 4. Now, apply the second data at SD1. Apply a clock pulse. We now observe that the earlier data is shifted from QA to QB, and the new data appears at QA. 5. Repeat the earlier step to enter data, until all bits are entered one by one. th
6. At the end of the 4 clock pulse, we notice that all 4 bits are available at the parallel output pins QA through QD. 7. Enter more bits to see there is a right shifting of bits with each succeeding clock pulse. Dept. Of ECE.
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C. Serial In-Serial Out Mode: 1. Connections are made as shown in the SISO circuit diagram. 2. Make sure the 7495 is operating in SIPO mode by ensuring Pin 6 (Mode) is set to LOW, and connect clock input to Clk 1(Pin 9). 3. The 4 bits are applied at the Serial Input pin (Pin 1), one by one, with a clock pulse in between each pair of inputs to load the bits into the IC. th 4. At the end of the 4 clock p u lse, th efirstd a tabit, „ d 0‟ a p p e ras a t th eoutpu t pin
QD.
5. A p p ly a n o ht e r c lock p ulse , to get the se c on ddata b it „d 1‟ at QD. Applying yet a n o th ecr lock p u lseg e tsth ethird data b it „ d 2‟ a t QD, and so on. 6. Thus we see the IC 7495 operating in SISO mode, with serially applied inputs appearing as serial outputs. D. Parallel In-Serial Out Mode: 1. Connections are made as shown in the PISO circuit diagram. 2. Now apply the 4-bit data at the parallel input pins A, B, C, D (pins 2 through 5). 3. Keeping the mode control M on HIGH, apply one clock pulse. The data applied at the parallel input pins A, B, C, D will appear at the parallel output pins QA, QB, QC, QDrespectively. 4. Now set the Mode Control M to LOW, and apply clock pulses one by one. Observe the data coming out in a serial mode at QD. 5. We observe now that the IC operates in PISO mode with parallel inputs being transferred to the output side serially. E. Parallel In-Parallel Out Mode: 1. Connections are made as shown in the PIPO mode circuit diagram. 2. Set Mode Control M to HIGH to enable Parallel transfer. 3. Apply the 4 data bits as input to pins A, B, C, D. 4. Apply one clock pulse at Clk 2 (Pin 8). 5. Note that the 4 bit data at parallel inputs A, B, C, D appears at the parallel output pins QA, QB, QC, QDrespectively.
Dept. Of ECE.
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IC 7495 Pin Diagram:
A. SIPO Mode (Left Shift) Circuit:
Truth Table:
Clock
1
Serial I/P
QA
QB
QC
QD
1
1
X
X
X
1
2
0
X
X
1
0
3
1
X
1
0
1
4
1
1
0
1
1
B. SIPO MODE (Right Shift) Circuit:
Truth Table: Clock
Dept. Of ECE.
52
Serial I/P
QA
QB
QC
QD
1
1
1
X
X
X
2
0
0
1
X
X
3
1
1
0
1
X
4
1
1
1
0
1
BTLInstitute of Technology & Management
C. SISO Mode Circuit:
Truth Table:
Clock
Serial I/P
QA QB QC
QD
1
d0=0
0
X
X
X
2
d1=1
1
0
X
X
3
d2=1
1
1
0
X
4
d3=1
1
1
1
0=d0
5
X
X
1
1
1=d1
6
X
X
X
1
1=d2
7
X
X
X
X
1=d3
D. PISO Mode Circuit:
Truth Table:
Mode
Dept. Of ECE.
53
Clk
Parallel I/P
Parallel O/P
A
B C D QA QB QC QD
1
1
1
0
1
1
0
1
1
0
2
X
X X X
X
1
0
1
0
3
X
X X X
X
X
1
0
0
4
X
X X X
X
X
X
1
1
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E. PIPO Mode Circuit:
Truth Table:
Clk
Parallel I/P
Parallel O/P
A B C D QA QB QC QD 1
Dept. Of ECE.
54
1
0
1
1
1
0
1
1
BTLInstitute of Technology & Management
Experiment No. 12
RING COUNTER /JOHNSON COUNTER Aim: – To design and study the operation of a ring counter and a Johnson Counter. Components Required: -
IC 7495, IC 7404, etc.
Procedure: 1. Make the connections as shown in the respective circuit diagram for the Ring Counter. 2. Apply an initial input (1000) at the A, B, C, D pins respectively. 3. Keep Select Mode = HIGH (1) and apply one clock pulse. 4. Next, Select Mode = LOW (0) to switch to serial mode and apply clock pulses. 5. Observe the output after each clock pulse, record the observations and verify that they match the expected outputs from the truth table. 6. Repeat the same procedure as above for the Johnson Counter circuit and verify its operation. A. Ring Counter Circuit:
Truth Table: Mode Clock QA QB QC QD
Dept. Of ECE.
55
1
1
1
0
0
0
0
2
0
1
0
0
0
3
0
0
1
0
0
4
0
0
0
1
0
5
1
0
0
0
0
6
0
1
0
0
BTLInstitute of Technology & Management
B. Johnson Counter Circuit:
Truth Table: Mode Clock QA QB QC QD
Dept. Of ECE.
56
1
1
1
0
0
0
0
2
1
1
0
0
0
3
1
1
1
0
0
4
1
1
1
1
0
5
0
1
1
1
0
6
0
0
1
1
0
7
0
0
0
1
0
8
0
0
0
0
0
9
1
0
0
0
0
10
1
1
0
0
BTLInstitute of Technology & Management
Experiment No. 13
SEQUENCE GENERATOR Aim: – To design and study the operation of a Sequence Generator. Components Required: -
IC 7495, IC 7486, etc.
Theory: In ord e rto gen erate a s eq u e n coef len g th„S‟ , it is n ec e sary s to u s eat least„N‟ n umb e rof Flip-flops, in order to satisfy the condition . The given sequence length S = 15 Therefore, N = 4 Note: There is no guarantee that the given sequence can be generated by 4 flip-flops. If the sequence is not realizable by 4 flip-flops, we need to use 5 flip-flops, and so on. Procedure:1. Truth table is constructed for the given sequence, and Karnaugh maps are drawn in order to obtain a simplified Boolean expression for the circuit. 2. Connections are made as shown in the circuit diagram. 3. Mode M is set to LOW (0), and clock pulses are fed through Clk 1 (pin 9). 4. Clock pulses are applied at CLK 1 and the output values are noted, and checked against the expected values from the truth table. 5. The functioning of the circuit as a sequence generator is verified. Circuit:
Dept. Of ECE.
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BTLInstitute of Technology & Management
Truth Table:
Map Value
Karnaugh Map:
O/p Clock QA QB QC QD D
15
1
1
1
1
1
0
7
2
0
1
1
1
0
3
3
0
0
1
1
0
1
4
0
0
0
1
1
8
5
1
0
0
0
0
4
6
0
1
0
0
0
2
7
0
0
1
0
1
9
8
1
0
0
1
1
12
9
1
1
0
0
0
6
10
0
1
1
0
1
11
11
1
0
1
1
0
5
12
0
1
0
1
1
10
13
1
0
1
0
1
13
14
1
1
0
1
1
14
15
1
1
1
0
1
1
1
1
1
1 1
Dept. Of ECE.
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Syllabus LOGIC DESIGN LAB (Common to EC/TC/EE/IT/BM/ML) Sub Code :10ESL38
IA Marks : 25
Hrs/ Week : 03
Exam Hours : 03
Total Hrs.:
Exam Marks : 50
NOTE: Use discrete components to test and verify the logic gates. LabView can be used for designing the gates along with the above. 1. Simplification, realization of Boolean expressions using logic gates/Universal gates. 2. Realization of Half/Full adder and Half/Full Subtractors using logic gates. 3. (i)Realization of parallel adder/Subtractors using 7483 chip (ii) BCD to Excess-3 code conversion and vice versausing 7483 chip. 4. Realization of Binary to Gray code conversion and vice versa 5. MUX/DEMUX – use of 74153, 74139 for arithmetic circuits and code converter. 6. Realization of One/Two bit comparator and study of 7485 magnitude comparator. 7. Use of Decoder chip to drive LED display. 8. Use of IC 74147 as Priority encoder. 9. Truth table verification of Flip-Flops: (i)
JK Master slave
(ii)
T type
(iii)
D type.
10. Realization of 3 bit counters as a sequential circuit and MOD – N counter design (7476, 7490, 74192,74193). 11. Shift left; Shift right, SIPO, SISO, PISO, PIPO operations using 74S95. 12. Wiring and testing Ring counter/Johnson counter. 13. Wiring and testing of Sequence generator.
http://www.scribd.com/doc/62491691/Logic-Design-Lab-Manual-10ESL38-3rd-sem-2011
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Possible Viva Questions 1. Define a logic gate. 2. What are basic gates?
Dept. Of ECE.
3. Why NAND and NOR gates are called as universal gates. 4. State De-morgans theorem 5. Give examples for SOP and POS 6. Explain how transistor can be used as NOT gate 7. Explain AND and OR gate using diodes 8. Realize logic gates using NAND and NOR gates only 9. Define LSI, MSI , SSI 10. List the applications of EX-OR and EX~NOR gates 11. What is a truth table? 12. What is a half adder? 13. Differentiate between half adder and half subtractor 14. What is a full adder? 15. Differentiate between combinational and sequential circuits. Give examples 16. Give the applications of combinational and sequential circuits 17. Give the block diagram of sequential circuits 18. Define flip flop 19. What is an excitation table/functional table 20. Differentiate between flip flop and latch 21. What is race around condition? 22. How do you eliminate race around condition 23. Give the block diagram of parallel adders 24. What are BCD Give their applications or uses 25. What is minterm and maxterm? 26. Explain the working of 7483 adder chip. Explain how it can be used as EX-3 to BCD conversion and vice versa 27. Define multiplexer/ data selector 28. What is a Demultiplexer? 29. Give the applications of mux and demux 30. What is a encoder and decoder 31. Compare mux and encoder 32. Compare demux and decoder 33. What is a priority encoder? 34. What is a code converter? 35. What are counters? Give their applications 36. Compare synchronous and asynchronous counters 37. What is a ripple counter? 38. What is modulus of a number? 39. What is a shift register? 40. Explain how a shift register can be used as ring and johnson counter 41. Give the applications of johnson and ring counters 42. What is an up counter and down counter? 43. What is common cathode and common anode LED? 44. What is LCD and LED. 45. What is a static and a dynamic display. 46. List the types of LCD's and LED's. 47. What does LS stand for, in 74LS00? 48. Mention the different logic families. 60
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49. Which is the fastest logic?
Dept. Of ECE.
61
BTLInstitute of Technology & Management
