1. ECE/CS 352 Digital System Fundamentals© T. Kaminski & C. Kime 1 ECE/CS 352 Digital Systems Fundamentals Spring 2001 Chapter 4 – Part 3 Tom Kaminski & Charles R. Kime

2. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 2 Overview of Chapter 4 Types of Sequential Circuits Storage Elements –Latches –Flip-Flops Sequential Circuit Analysis –State Tables –State Diagrams Sequential Circuit Design –Specification –Assignment of State Codes –Implementation –HDL Representation

3. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 3 Sequential Circuit Analysis Combina- tional Logic Storage Elements Inputs State Next State Outputs CLK

4. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 4 Example (from Fig. 4-18)

5. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 5 Example (Fig. 4-18) (Continued)

6. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 6 Example (Fig. 4-18) (Continued) Where in time are inputs, outputs and states defined? 0 0 0 0 1 1 1 0

7. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 7 Example (Fig. 4-18) (Continued) Where in time are inputs, outputs and states defined? 0 0 0 0 1 1 1 0

8. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 8 State Table Characteristics

9. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 9 Example: State Table (Fig. 4-18) The STATE TABLE can be filled in using the next state and output equations. 

10. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 10 Alternate State Table Format An alternate format just shows the next state and output as a function of the current state, but broken out by input.

11. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 11 State Table Characteristics

12. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 12 State Diagrams

13. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 13 State Diagram (Example)

14. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 14 Flip-Flop Input Functions

15. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 15 Analysis with Other Flip-Flops

16. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 16 Characteristic Tables (Review 4-1)

17. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 17 JK Flip-Flop Circuit Analysis

18. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 18 JK Flip-Flop Analysis (Cont.)

19. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 19 JK Flip-Flop, Next State

20. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 20 JK Flip-Flop, Next State

21. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 21 Review: Sequential Circuits

22. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 22 Moore and Mealy Models Sequential Logic, or Sequential Machines are also called Finite State Automata. Two formal models exist:

23. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 23 Moore and Mealy Example

24. ECE/CS 352 Digital System Fundamentals Chapter 4 Page 24 Moore and Mealy Example Tables