1. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 1 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I 14 Digital Systems

2. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 2 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.1 RS flip-flop symbol and truth table OutputsInputs S R Q Q S R 0 0 1 1 Q 0 1 0 0 Present state Reset Set Disallowed

3. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 3 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.2 Timing diagram for the RS flip- flop

4. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 4 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.3 Logic gate implementation of the RS flip-flop Q Q R S Q Q R S

5. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 5 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.4 RS flip-flop with enable, present, and clear lines Q Q S R E Preset (P) Clear ( C) Preset Enable Clear Q S R Timing diagram

6. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 6 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.5 Data latch and associated timing diagram

7. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 7 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.6 D flip-flop functional diagram, symbol, and timing waveforms

8. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 8 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.7 JK flip-flop functional diagram and device symbol

9. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 9 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.8 Truth table for JK flip-flop J n J CLK Q JK flip-flop K n Q n +1 Q n 0 (reset) 1 (set) Q n (toggle) K Q 0 0 1 1 0 1 0 1

10. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 10 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.10 Binary up counter functional representation, state table, and timing waveforms

11. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 11 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.11 Decade counter

12. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 12 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.12 Ripple counter 11 1

13. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 13 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.15 Three-bit synchronous counter

14. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 14 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.16 Ring counter input

15. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 15 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.21 Four-bit parallel register

16. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 16 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.22 Four-bit shift register

17. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 17 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.24 a b c d e f g C B ABCD to seven-segment decoder D

18. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 18 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.26 Three-bit binary counter and state diagram

19. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 19 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.27 State diagram of a modulo-4 up-down counter 00 01 10 11

20. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 20 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.28 Karnaugh maps for flip-flop inputs in modulo-4 counter

21. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 21 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.29 Implementation of modulo-4 counter

22. © The McGraw-Hill Companies, Inc. 2000 McGraw-Hill 22 PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION G I O R G I O R I Z Z O N I Figure 14.30 Structure of a digital data acquisition and control system User Sensor signals To displays To actuators Signal interface Software Communication links Other computers and instrumentation systems Microcomputer