Karnaugh map of a J/K Flip Flop

Discussion in 'Homework Help' started by Sloprano, Nov 13, 2010.

  1. Sloprano

    Thread Starter New Member

    Nov 13, 2010

    I'm having some problems with a step circuit going through a J/K Flip flop that I hope someone can help me with.

    The circuit is presented in the crude image below. It travels from 00 to 11; forward, backwards or just stays in a loop. E determines if it's moving (1 = move, 0 = loop on current posistion). F determines the direction(1 = clockwise, 0 = counter-clockwise).

    Also in the image I've made a diagram based on the J/K Excitation table on what values J(A), K(A), J(B) and K(B) will have.

    What I'm trying to find is the function for each state through a Karnaugh diagram. Seeing as if E is 0 then F is always X(Don't Care), will this make it impossible to have an" E = 0 F = 0" input?

    I tried to make a K-map of the J(A) function and can I use "0X" instead of "01" seeing as it dosen't excist for EF?

    Thanks in advance.

  2. ffriedmann

    New Member

    Nov 12, 2010
    Long time since I did one of these, but he most helpful text I have found on this subject was the "Digital Logic and State Machine Design" by Stephen Comer. Very understandable. You can find it on Amazon and other places.
  3. Georacer


    Nov 25, 2009
    Is your problem filling the Karnaugh map or solving it? Just for the record you will need 4 4-input Karnaugh maps.

    You can write 0X in the state table, but you will have to be very careful when you fill the Karnaugh map, not to forget any cell.

    Don't try to find any "smart solutions" from the relation of E with F. The Karnaugh map will do that for you.