2-bit binary counter question

Discussion in 'The Projects Forum' started by hazim, Jan 25, 2008.

  1. hazim

    Thread Starter Active Member

    Jan 3, 2008
    419
    13
    hi..this is a 2-bit binary counter i build it from two j-k flip-flops....i don't know what's the problem with it..it always gives 11; maybe the problem is with the clear and preset connection. i'm in a hurry, can any body help me please?...
    [​IMG]
     
  2. techroomt

    Senior Member

    May 19, 2004
    198
    1
    it is very blurry for me, but i think you need to tie the "async set" inputs high (assuming they are active low), they appear to be n/c.
     
  3. hazim

    Thread Starter Active Member

    Jan 3, 2008
    419
    13
    please i'm a beginner in logic circuits :)..what is the "async set" and n/c, i don't understand you
     
  4. nomurphy

    AAC Fanatic!

    Aug 8, 2005
    567
    12
    Funny, but if I am not logged-in your attachment opens to an easy to read page. If I am logged-in, then it opens as a small unreadable figure.


    Pins 2 & 7 need to be tied high same as pins 3 & 8.

    Also, with a 30Hz input, the LED's will flash so fast they may always appear to be on.
    To be able to see this, change the input to 1 Hz.
     
  5. hazim

    Thread Starter Active Member

    Jan 3, 2008
    419
    13
    oh thanks, it worked now, but with 30 frequency they flash with about a 1s period, i always use the clock with >30Hz frequency.....it's not logic to be like that, but this is how it works.....what are you both commetting about the attachment, it's normal here and i'm logged in, you should click on it and it opens in new window....anyway thanks for you;)
     
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