Help with state table

Discussion in 'Homework Help' started by arcsky, Apr 17, 2009.

  1. arcsky

    Thread Starter Member

    Apr 17, 2009
    12
    0
    Hello all,
    I wonder if you guys maybe can help me out with this small problem,
    http://hem.passagen.se/dmsn/design.jpg
    The two lines in the state-table i dont understand how to fill it.
    I doesn't understand how to think.



    Thanks in advance
     
  2. SawabyPlus

    Member

    Feb 27, 2009
    14
    0
    you may fill them the same way you've filled the other 2 rows.
    starting from state (01) it moves to state (11) if a = '0' which means the first and last column.
    it also moves to state (00) if a = '1' which is the 2nd and 3rd column.

    same for state (10).

    but i think there's a contradiction in state (11) transition conditions, where both conditions are active when a = '0' and b = '0', is there any kind of priority? check it out!
     
  3. arcsky

    Thread Starter Member

    Apr 17, 2009
    12
    0
    Hi thanks for trying to help.
    But that was wrong :/
    Also i dont think two states can have same rows.
     
  4. SawabyPlus

    Member

    Feb 27, 2009
    14
    0
    i don't understand what's wrong with my answer!
    that would be the second row, and as shown it would be [ 11 | 00 | 00 | 11 ]

    also fourth row would be [ 10 | 10 | 11 | 11 ].

    Also i still believe the state diagram has some contradiction concerning transition conditions of state (11), unless some sort of priority applies, because if a and b both equal zero then both conditions are correct!

    what's wrong with what i've said? can u clarify?
     
  5. arcsky

    Thread Starter Member

    Apr 17, 2009
    12
    0
    Ah nice i think i understand your idea now on row 2 and 4.
    But hmm the state (11) is wierd yes i have no idea why.
    But i dont think teacher have made a wrong diagram.
    I dont know more than all the info on the picture...
    How would you think row for state (11) should be?

    Is this maybe any important ?
    "A simple sequential circuit with state diagramet as above to the left to be realized in a PLD circuit
    (The first PAL circuit 16R4 that was introduced in 1978 would reach more than ...)"
     
    Last edited: Apr 18, 2009
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