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Homework Help: Urgent help

  1. Jan 30, 2009 #1
    Hi guys

    I´m new on this and i have to finish this in 20 hours.
    The problem is that i don´t know where i have to put a counter to count 4 cicles when the traffic light is green, can you help me please?
    The counter can be with flip-flop d, flip-flop t or flip-flop jk, what are the best to use asa counter? I have tried with 4 flip-flop d and i don´t know where is the right place to put it.
    Can you show 1 exemple for the image attached?

    http://img297.imageshack.us/img297/6318/circuitll7.th.jpg [Broken]

    Thanks in advance
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jan 31, 2009 #2


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    Science Advisor

    Sorry, which light? The four in the middle? The 9 in the upper right hand corner? Since nothing is labelled, I can't tell.

    Regardless, you need to put inputs into your counter. If your counter takes in a single input, from, say, a rising edge, clearly, you'd need to somehow combine all the outputs going to the lights so that you get one output which produces a high output (and rising edge) when any of the inputs go high. This single output would then go to the counter.

    So, how would you combine these outputs? HINT: It's a simple function.
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