Build state diagram from mod 5 counter

Discussion in 'Homework Help' started by Asheara, Nov 29, 2016.

  1. Asheara

    Thread Starter New Member

    Nov 3, 2016
    11
    0
    Hi guys,

    I have this exercise about Moore I have to deliver today done but I would like to be sure if it is correct, so if you could take a look and validate my work that'd be great.

    mod5counter.png

    Si+1 = (Si + E) mod 5

    This a mod 5 counter, on each clock rise Si+1 is calculated incrementing the previous S from the previous clock rise based on value received in E.
    This E has 2 bits and can value 1, 2 or 3. Value 0 can't never happen.
    At initialization moment, S should be 0 (S0=0)

    For example, if E = 2, S values on each clock rise will be: 0,2,4,1,3,0.

    E is asynchronous and can change at any moment.
    S is synchronous and should be constant during the clock cycle.
    The considered value of E to make the transition of each Si is the value just at the rise edge.


    So far I have this state table and state diagram below, if someone could just validate if im following the correct path please or give me a clue about what am I doing wrong.
    state_table.png

    state_diagram_ok.png

    Thank you!
     
  2. WBahn

    Moderator

    Mar 31, 2012
    23,082
    6,938
    You need to start looking at your own solutions and determining if they are correct.

    Start with the low hanging fruit. If E has three possible values, then shouldn't each state have three arrows leaving it? Do they?

    Isn't there a simple pattern to where the arrows go from a particular state? Do the arrows in your diagram follow that pattern?

    Does it make sense for the arrows from a given state to end up in the same next state for different values of E? Do you have any states that have this behavior?

    You stated that E can never be 0, yet your table includes situations in which E = 0 but does not include all situations in which E = 3.

    Do you really need someone half way around the world pointing these kinds of things out to you?

    Always ask if your solution makes sense.
     
  3. Asheara

    Thread Starter New Member

    Nov 3, 2016
    11
    0
    Hi,

    You're right, the table has errors, E can't be 0, so Im modifying it to fix it and fix the state diagram in consequence.

    Thank you,
     
  4. Asheara

    Thread Starter New Member

    Nov 3, 2016
    11
    0
    Hi,

    I think this makes more sense:
    state_table_01.png

    state_diagram - Page 1.png
     
  5. WBahn

    Moderator

    Mar 31, 2012
    23,082
    6,938
    That looks fine.
     
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