PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION 14 Digital Systems Mc. Graw-Hill 1 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 1 RS flip-flop symbol and truth table S Q Inputs Outputs R Mc. Graw-Hill Q S R Q 0 0 Present state 0 1 Reset 1 0 Set 1 0 Disallowed 2 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 2 Timing diagram for the RS flipflop Mc. Graw-Hill S R Q 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 1 Time 1 S 0 1 R Flip-flop is reset is set 3 GIORGIO RIZZONI Q Flip-flop is reset is set (but Q = 0) already © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 3 Logic gate implementation of the RS flip-flop S S Q Q Q R Mc. Graw-Hill 4 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 4 RS flip-flop with enable, present, and clear lines Preset (P ) Clear S Q S E R Q R Clear (C) Q Enable Timing diagram Mc. Graw-Hill 5 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 5 Data latch and associated timing diagram D Enable S E R Q D Q Q E Q D Enable Q Mc. Graw-Hill 6 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 6 D flip-flop functional diagram, symbol, and timing waveforms D Q D S 1 Q 1 S 2 Q R 1 Q 1 R 2 Q Q E 1 2 E 2 CLK D Q Q =Q 2 CLK Q Device symbol CLK Functional diagram Mc. Graw-Hill 1 7 GIORGIO RIZZONI Timing diagram © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 7 JK flip-flop functional diagram and device symbol J CLK K Master S 1 Q 1 Slave S 2 Q J E 1 E 2 Q CLK R 1 Q 2 R 2 K Q Q Device symbol Functional diagram Mc. Graw-Hill 8 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 8 Truth table for JK flip-flop J Q CLK K Q JK flip-flop Mc. Graw-Hill Qn +1 Jn Kn 0 0 Qn 0 1 0 (reset) 1 0 1 1 1 (set) Q n(toggle) 9 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 10 Binary up counter functional representation, state table, and timing waveforms Reset Clock input Input pulses 3 -bit binary counter b 2 b 1 b 0 Functional representation of binary counter b 2 State b 1 b 0 0 0 1 2 0 1 0 3 4 0 1 1 0 5 1 0 1 6 1 1 0 7 1 1 1 Timing table Clock t b 0 t b 1 t b 2 Timing diagram Mc. Graw-Hill 10 GIORGIO RIZZONI t © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 11 Decade counter Input pulses b 3 b 2 b 1 b 0 0 0 1 2 0 0 1 0 3 0 0 1 1 4 0 1 0 0 5 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 Mc. Graw-Hill Reset 4 -bit binary counter Clock b 3 b 2 b 1 b 0 Reset 11 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 12 Ripple counter Input Q 3 Q 2 Q 1 1 1 J Clock input J Q CLK K Q 1 Mc. Graw-Hill 1 Q 0 0 0 J 0 0 1 0 Q CLK K K 0 1 1 1 0 0 1 Q 2 Q 12 GIORGIO RIZZONI 3 1 1 0 1 1 1 © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 15 Three-bit synchronous counter Q 0 1 Q 2 T Q 0 T Q 1 T Q 2 CLK CLK Q 0 Q 1 Q 2 Clock input Mc. Graw-Hill 13 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 16 Ring counter Init Q 3 Q 2 Q 1 Q 0 PR S Q 3 CLK CLR S Q 2 CLR S Q 1 CLR S Q 0 CLK CLK R Q 3 R Q 2 R Q 1 0 Clock input Mc. Graw-Hill 14 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 21 Four-bit parallel register Q 0 Q 1 D Q 0 D Q CLK “Load” input Mc. Graw-Hill b 0 Q 2 b 1 Q 3 1 D Q 2 D Q 3 CLK CLK b 2 15 GIORGIO RIZZONI b 3 © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 22 Four-bit shift register Q 0 Serial input b 1 Q 2 Q 3 0 D Q 1 D Q 2 D Q 3 CLK CLK D Q Serial output Clock input Mc. Graw-Hill 16 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 24 D a C b B A c BCD to seven-segment decoder d e f g Mc. Graw-Hill 17 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 26 Three-bit binary counter and state diagram 1 T 3 Q 3 T 2 Q 3 Q 2 T 1 Q 2 Q 1 CLK Mc. Graw-Hill 000 001 010 011 110 101 100 18 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 27 State diagram of a modulo-4 up -down counter 01 00 10 11 Mc. Graw-Hill 19 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 28 Karnaugh maps for flip-flop inputs in modulo-4 counter x Q 1 Q 2 1 0 d 0 1 0 d d 0 1 0 S 1 x R 1 Q 2 x Q 1 Q 2 1 0 0 1 0 1 1 0 S 2 Mc. Graw-Hill R 2 20 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 29 Implementation of modulo-4 counter x Mc. Graw-Hill S 1 Q 1 R 1 Q 1 S 2 Q 2 R 2 Q 2 21 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 14. 30 Structure of a digital data acquisition and control system Sensor signals Other computers and instrumentation systems Signal interface User Software Communication links Microcomputer Signal interface To displays Mc. Graw-Hill To actuators 22 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000