Need Help with counters!!!Please

Discussion in 'Homework Help' started by kjs_123, Oct 19, 2008.

  1. kjs_123

    Thread Starter Member

    Oct 16, 2008
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    0
    How to Design two decade counters that are cascaded to produce an output from 00 to 99 on 8 digital outputs. Also to Arrange an input that can stop the count when brought low – use a switch on the development board for this purpose. Drive this design from your 1 Hz source.


    Any Suggestion would be helpfull....


    Thanks
    KJ
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Get a data sheet for a 74162 and look at the internal logic. Pretty simple.
     
  3. kjs_123

    Thread Starter Member

    Oct 16, 2008
    22
    0
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    Page 9 of the datasheet shows how to arrange a BCD counter. Just ignore the parallel load logic. Pay attention to how the logic stops the count at 9 rather than F.

    If you can't use a counter IC, then you can use standard logic to duplicate the function.
     
  5. kjs_123

    Thread Starter Member

    Oct 16, 2008
    22
    0
    This is what I did in Quartus II....this BCD counter counts from 0-9 and then resets.....Please advice.....
    [​IMG]
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    Then you need another one to count from 10 to 90.
     
  7. kjs_123

    Thread Starter Member

    Oct 16, 2008
    22
    0
    You mean I will need to draw another one of them.....?
    How do I join them.....

    Thanks
    KJ
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    282
    The idea is that ANDing the outputs for '9' and the clock take the state back to 0. For the next stage, the previous state of '9' and a clock should advance the count.
     
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