BZUPAGES.COM1 Chapter 9 Counters

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BZUPAGES.COM3 Figure 9--1 A 2-bit asynchronous binary counter. Asynchronous Counter Operation

BZUPAGES.COM4 Figure 9--2 Timing diagram for the counter of Figure 9-1. As in previous chapters, output waveforms are shown in green.

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7 Figure 9--3 Three-bit asynchronous binary counter and its timing diagram for one cycle.

BZUPAGES.COM8 Figure 9--4 Propagation delays in a 3-bit asynchronous (ripple-clocked) binary counter.

BZUPAGES.COM9 Figure 9--5 Four-bit asynchronous binary counter and its timing diagram.

BZUPAGES.COM10 Figure 9--6 An asynchronously clocked decade counter with asynchronous recycling.

BZUPAGES.COM11 Figure 9--7 Asynchronously clocked modulus-12 counter with asynchronous recycling.

BZUPAGES.COM12 Figure A 2-bit synchronous binary counter. Synchronous Counter Operation

BZUPAGES.COM13 Figure Timing details for the 2-bit synchronous counter operation (the propagation delays of both flip-flops are assumed to be equal).

BZUPAGES.COM14 Figure Timing diagram for the counter of Figure 9-11.

BZUPAGES.COM15 Figure A 3-bit synchronous binary counter.

BZUPAGES.COM16 Figure Timing diagram for the counter of Figure 9-14.

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BZUPAGES.COM18 Figure A 4-bit synchronous binary counter and timing diagram. Points where the AND gate outputs are HIGH are indicated by the shaded areas.

BZUPAGES.COM19 Figure A synchronous BCD decade counter.

BZUPAGES.COM20 Figure Timing diagram for the BCD decade counter (Q 0 is the LSB).

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BZUPAGES.COM22 Up/Down Synchronous Counter

BZUPAGES.COM23 Figure A basic 3-bit up/down synchronous counter.

BZUPAGES.COM24 Figure 9—24 : Example Timing Diagram

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BZUPAGES.COM26 Figure General clocked sequential circuit. Design of Synchronous Counters

BZUPAGES.COM27 Figure State diagram for a 3-bit Gray code counter. Step 1: State Diagram

BZUPAGES.COM28 Step 2: Next-State Table

BZUPAGES.COM29 Step 3: Flip-Flop Transition Table

BZUPAGES.COM30 Figure Examples of the mapping procedure for the counter sequence represented in Table 9-7 and Table 9-8. Step 4: Karnaugh Maps

BZUPAGES.COM31 Figure Karnaugh maps for present-state J and K inputs. Step 5: Logic Expressions for Flip-Flop Inputs

BZUPAGES.COM32 Figure Three-bit Gray code counter. Step 6: Counter Implementation

BZUPAGES.COM33 Figure 9—32 : Example 9-5

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BZUPAGES.COM36 Figure 9--33

BZUPAGES.COM37 Figure 9--34

BZUPAGES.COM38 Figure Example State diagram for a 3-bit up/down Gray code counter.

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BZUPAGES.COM41 Figure J and K maps for Table The UP/DOWN control input, Y, is treated as a fourth variable.

BZUPAGES.COM42 Figure Three-bit up/down Gray code counter.