Digital Counters are used in counting an event. This example will explains the design of Mod 5 Synchronous using J K Flip Flop

1. Mod 5 Synchronous Counter using J K flip-flop
Dr. Manjunatha. P
manjup.jnnce@gmail.com
Professor
Dept. of ECE
J.N.N. College of Engineering, Shimoga
March 13, 2022

2. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

3. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

4. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

5. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

6. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
3 Step 3: Excitation table based on the type of Flip-Flop
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

7. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
3 Step 3: Excitation table based on the type of Flip-Flop
4 Step 4: State Excitation table
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

8. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
3 Step 3: Excitation table based on the type of Flip-Flop
4 Step 4: State Excitation table
5 Step 5: Obtaining Flip-Flop inputs using K map
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

9. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
3 Step 3: Excitation table based on the type of Flip-Flop
4 Step 4: State Excitation table
5 Step 5: Obtaining Flip-Flop inputs using K map
6 Step 6: Draw the circuit diagram based on K map equations
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

10. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Design a synchronous Mod 5 counter using J K flip-flop
The following steps are used in designing a synchronous counter:
1 Step 1: No of Flip-Flops required
2 Step 2: Draw the State diagram
3 Step 3: Excitation table based on the type of Flip-Flop
4 Step 4: State Excitation table
5 Step 5: Obtaining Flip-Flop inputs using K map
6 Step 6: Draw the circuit diagram based on K map equations
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 2 / 9

11. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

12. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

13. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
The number of flip flops ’n’ required for a modulo 5 counter is:
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

14. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
The number of flip flops ’n’ required for a modulo 5 counter is:
2n−1
<= N
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

15. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
The number of flip flops ’n’ required for a modulo 5 counter is:
2n−1
<= N
23−1
<= 5
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

16. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
The number of flip flops ’n’ required for a modulo 5 counter is:
2n−1
<= N
23−1
<= 5
For N=5, the number of flip flops required is 3
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

17. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 1: No of Flip-Flops required
Binary modulo 5 counter can count from 0 to 4.
The number of flip flops ’n’ required for a modulo 5 counter is:
2n−1
<= N
23−1
<= 5
For N=5, the number of flip flops required is 3
Step 2: State diagram
001
100
011 010
000
0
4
3
2
1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 3 / 9

18. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 3: J K excitation table
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 4 / 9

19. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 3: J K excitation table
Table 1: J K excitation table
Qn Qn+1 J K
0 0 0 X
0 1 1 X
1 0 X 1
1 1 X 0
001
100
011 010
000
0
4
3
2
1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 4 / 9

20. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 3: J K excitation table
Table 1: J K excitation table
Qn Qn+1 J K
0 0 0 X
0 1 1 X
1 0 X 1
1 1 X 0
001
100
011 010
000
0
4
3
2
1
Step 4: State excitation table
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 4 / 9

21. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 3: J K excitation table
Table 1: J K excitation table
Qn Qn+1 J K
0 0 0 X
0 1 1 X
1 0 X 1
1 1 X 0
001
100
011 010
000
0
4
3
2
1
Step 4: State excitation table
Present State Next State Flip flop Inputs
Q3 Q2 Q1 Q3 Q2 Q1 J2 K2 J1 K1 J0 K0
0 0 0 0 0 1 0 X 0 X 1 X
0 0 1 0 1 0 0 X 1 X X 1
0 1 0 0 1 1 0 X X 0 1 X
0 1 1 1 0 0 1 X X 1 X 1
1 0 0 0 0 0 X 1 0 X 0 X
1 0 1 - - - - - - - - -
1 1 0 - - - - - - - - -
1 1 1 - - - - - - - - -
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 4 / 9

22. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 5: Obtaining Flip-Flop inputs using K map
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 5 / 9

23. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 5: Obtaining Flip-Flop inputs using K map
Present State Next State Flip flop Inputs
Q3 Q2 Q1 Q3 Q2 Q1 J2 K2 J1 K1 J0 K0
0 0 0 0 0 1 0 X 0 X 1 X
0 0 1 0 1 0 0 X 1 X X 1
0 1 0 0 1 1 0 X X 0 1 X
0 1 1 1 0 0 1 X X 1 X 1
1 0 0 0 0 0 X 1 0 X 0 X
1 0 1 - - - - - - - - -
1 1 0 - - - - - - - - -
1 1 1 - - - - - - - - -
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
0
2 1 0
J =Q Q
0
0 1
X
X
X
X
J2
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
2
K =1
X
X
X
X
X
1
K2
X
X
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 5 / 9

24. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 5: Obtaining Flip-Flop inputs using K map
Present State Next State Flip flop Inputs
Q3 Q2 Q1 Q3 Q2 Q1 J2 K2 J1 K1 J0 K0
0 0 0 0 0 1 0 X 0 X 1 X
0 0 1 0 1 0 0 X 1 X X 1
0 1 0 0 1 1 0 X X 0 1 X
0 1 1 1 0 0 1 X X 1 X 1
1 0 0 0 0 0 X 1 0 X 0 X
1 0 1 - - - - - - - - -
1 1 0 - - - - - - - - -
1 1 1 - - - - - - - - -
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
0
1 0
J =Q
X
1 X
X
X
X
0
J1
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
X

1 0
K Q
0
X 1
X
X
X
X
K1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 6 / 9

25. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 5: Obtaining Flip-Flop inputs using K map
Present State Next State Flip flop Inputs
Q3 Q2 Q1 Q3 Q2 Q1 J2 K2 J1 K1 J0 K0
0 0 0 0 0 1 0 X 0 X 1 X
0 0 1 0 1 0 0 X 1 X X 1
0 1 0 0 1 1 0 X X 0 1 X
0 1 1 1 0 0 1 X X 1 X 1
1 0 0 0 0 0 X 0 0 X 0 X
1 0 1 - - - - - - - - -
1 1 0 - - - - - - - - -
1 1 1 - - - - - - - - -
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
 2
0
J Q
1
X
X
X
X
0
J0
0
7 6
5
4
3 2
1
0
1
00 01 11 10
Q2
Q1
Q0
X
0
K =1
X
1 1
X
X
X
X
K0
X
1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 7 / 9

26. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 6: Draw the circuit diagram based on K map equations
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 8 / 9

27. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 6: Draw the circuit diagram based on K map equations
J2 = Q1Q0 K2 = 1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 8 / 9

28. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 6: Draw the circuit diagram based on K map equations
J2 = Q1Q0 K2 = 1
J1 = Q0 K1 = Q0
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 8 / 9

29. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 6: Draw the circuit diagram based on K map equations
J2 = Q1Q0 K2 = 1
J1 = Q0 K1 = Q0
J0 = Q2 K0 = 1
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 8 / 9

30. Synchronous Counter Mod 5 Synchronous Counter using J K flip-flop
Step 6: Draw the circuit diagram based on K map equations
J2 = Q1Q0 K2 = 1
J1 = Q0 K1 = Q0
J0 = Q2 K0 = 1
2
J
2
K
2
Q
2
Q
Ck FF
1
J
1
K
1
Q
1
Q
Ck FF
0
J
0
K
0
Q
0
Q
Ck FF
Clk
1
Vcc
2
Q 1
Q 0
Q
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 8 / 9

31. Thank You
Dr. Manjunatha. P (JNNCE) Mod 5 Synchronous Counter using J K flip-flop March 13, 2022 9 / 9