Help: 4-Bit Counter Schematic

Discussion in 'OT Technology' started by JustJeff, Oct 21, 2007.

  1. JustJeff

    JustJeff www.youtube.com/thisisjustjeff

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    Hey everyone. I usually don't need help with some of this Computer Engineering stuff, but I'm currently stumped and I have no idea what to do.

    Here's the question:

    Use the Counter-4 in LogicWorks to create a mod-11 counter, a counter that goes from 0-10, and then back to 0, using only the counter chip and any logic gates (and, or, nor, nand).

    [​IMG]

    CLK = Clock Edge
    CO = Carry Out
    D0-3 = Inputs
    Q0-3 = Outputs
    LD = Lead
    EN = Enable
    CLR = Clear
    Up = ...?


    So yeah, I don't know what to do with it.
     
  2. etech

    etech New Member

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    I haven't used that counter but the premise is fairly simple.

    I assume that it is a hex counter.( will count from 0 to F)

    Set the inputs that you need set.
    En=True
    Up=True
    D0-3 to False/0

    You will need a clock pulse for the clock input, a debounced switch for example.

    Now comes the logic, you will need to decode an hex 11 on the outputs( use and/nand gates and a clock pulse), when that is true, set the clear to true which will reset the counter to zero.
     
  3. JustJeff

    JustJeff www.youtube.com/thisisjustjeff

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    Okay, i see what you mean. I wired everything up: I just need to figure out how to make the initial state values so that it can count on the clock edges...


    Thanks for the help!
     
  4. copiertalk

    copiertalk Secure Our Borders! OT Supporter

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    you want it to count up to 10 (base 10) and then down to 10 (base 10). The way desribed above would reset the counter to zero and start over. To count down after 10 ( base 10 ) you would have to have a logic zero on the UP pin of the IC.

    I would have to dig up my old logic books to be of much help. Have you looked up adder schematics on google?

    What TTL chip number?
     

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