Building a set-dominant gated SR latch

Discussion in 'Homework Help' started by jegues, Oct 22, 2010.

  1. jegues

    Thread Starter Well-Known Member

    Sep 13, 2010
    A gated SR latch has unpredictable behavior if the S and R inputs are both equal to 1 when the Clk changes to 0. One way to solve the problem is to create a set-dominant gated SR latch in which the condition S = R = 1 causes the latch to be set to 1. Design a set-dominant gated SR latch and show the circuit.

    Okay I've provided my attempt in the figure attached as well as the solution given in another figure.

    I think there is a problem with the solution given. They state "Design a set-dominant gated SR latch", the latch they've provided in the solution is not a gated SR latch.

    Is the solution incorrect?
  2. Georacer


    Nov 25, 2009
    I 'm not into latches and FFs so deep, but you could say that there's a controlling gate before the latch, at the solution circuit. It's a matter of definition I guess.

    Your attempt is superior to the one proposed, as it incorporates both security checks.
  3. nyasha

    Active Member

    Mar 23, 2009
    They are both correct. But the one with the clock is far better. I would advise you to use 4 nand gates