Counters Using Flipflops.

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CSL 202, Counters Using Flipflops

• CEC

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Contents

• Counters using Flipflop ICs.
• Ring and Johnson Counters.
• Asynchronous Counters.
• Synchronous Counters.
• UP/Down Counters.
• Decade Counters.
• Timing Diagrams.
• Counter Applications.

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Counters using Flipflops

• Use of D flipflops or JK flipflops in T flipflop
  configuration.
• Each flipflop divides input frequency by two
  frequency divider.
• Counters can be binary or biquinary.
• Binary Counters straight sequence.
• Biquinary Counters skip interim states.
• Counters can be synchronous (clock driven) or
  asynchronous (ripple counter).

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T Flipflops

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Asynchronous Counters

• Also called ripple counters.
• Clock trigger to toggle LSB.
• Output of one flipflop to serve as clock for
  succeeding flipflop.
• Number of flipflops depend on maximum count and
  the total number of states of the counter.
• Maximum number of states 2N, N number of
  flipflops.

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Synchronous Counter

• All flipflops clocked from a single source.
• Clock common to all flipflops.
• Flipflops change states in synchronism with the
  clock.
• Number of flipflops depend on the maximum count
  and total number of states of the counter.
• Maximum number of states 2N, N number of
  flipflops.

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Ring Counter
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Johnson Counter(Twisted Ring Counter)

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Mode Controlled Ring/Johnson Counter
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4 bit Asynchronous Up Counter

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4 bit Asynchronous Down Counter

FF1
FF2
FF3
FF0
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4 bit Asynchronous Down Counter
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3 bit Asynchronous Up/Down Counter

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Asynchronous Decade Counter

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Asynchronous Decade Counter

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4 bit Synchronous Up Counter

FF1
FF2
FF0
FF3
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4 bit Synchronous Up Counter

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4 bit Synchronous Down Counter

FF1
FF2
FF3
FF0
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4 bit Synchronous Down Counter

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3 bit Synchronous Up/Down Counter

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Object Counter
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Object Counter
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Procedure

• Assemble the circuits on the breadboard provided
  along with the trainer kit.
• Initial reset/clear and LSB preset for the ring
  counter.
• Clock input to be applied from the clock source
  provided in the trainer kit.
• Outputs to be observed using LEDs provided in the
  trainer kit.
• Verify the state tables and draw timing diagrams.

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Youtube Resources

• https//www.youtube.com/watch?vKAPdyK1LxHg
• https//www.youtube.com/watch?vUHkR10Tvz5w
• https//www.youtube.com/watch?vuUVj5jCQMdc
• https//www.youtube.com/watch?vKk78ZPskzTw
• https//www.youtube.com/watch?v-SFU5voStlw

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Youtube Resources

• https//www.youtube.com/watch?v4PoFzsrA834
• https//www.youtube.com/watch?vQp2C-3kw_xk
• https//www.youtube.com/watch?vQp2C-3kw_xk
• https//www.youtube.com/watch?v4PoFzsrA834

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Thank You