is my state diagram and table right?

Discussion in 'Homework Help' started by koria, Jan 15, 2009.

  1. koria

    Thread Starter New Member

    Jan 15, 2009
    2
    0
    Hi all,

    I just follow an exercise from Embedded design system book (Frank Vahid and Tony Givargis). The problem from exercise 2.13

    One controller with two output (S01 and S11) is connected to decoder. Decoder has 4 lamps that will be blink with this sequence (0, 2, 1, 3, 0, 2 ,...).


    I try to make a state diagram and table like this attachment.

    please any one give me comment whenever it is right or wrong

    Best Regard
     
  2. RiJoRI

    Well-Known Member

    Aug 15, 2007
    536
    26
    I find marking states with "S0" or "State 0" helps a lot. It also indicates the first state. Also, "I" generally indicates "Input", and "Q" or "O" indicates "Output". I read the state diagram (assuming we begin at State A) as "IF Input SO1 == 0 AND Input S11 == 0, THEN GOTO State B." You may want to show what the outputs of State B are.

    Also, I'm having trouble associating the table with your definitions: Q0? Q1?

    Try sketching the circuit. Nothing fancy, just a couple of boxes with labeled lines between them.

    HTH,
    --Rich
     
  3. koria

    Thread Starter New Member

    Jan 15, 2009
    2
    0
    Hi HTH,

    1. S01 and S11 is output, not input. Please see the attachment that is described by this book. I think there is only one input in state register (clk)
    2. Q0 and Q1 are input from state register, and I0 and I1 are input to state register
    3. I think i don't have problem to drawing circuit if my state table correct

    I hope you can give more explanation

    regard,
     
    • 213.JPG
      213.JPG
      File size:
      8.4 KB
      Views:
      12
  4. RiJoRI

    Well-Known Member

    Aug 15, 2007
    536
    26
    (HTH means Hope This Helps! :D )

    You should fill in the decoder's outputs below, then show them in
    your state diagram. It would be under the [Sx] in my picture.

    Code ( (Unknown Language)):
    1.  
    2. Decoder              Decoder
    3.  INPUTS     STATE    OUTPUTS
    4. S01  S11           O1 O2 O3 O4
    5.  0    0       1
    6.  0    1       2
    7.  1    0       3
    8.  1    1       4
    9.  
    10.                  0,0              1,1        0,0
    11. [Initail State]-------[ S1 ]---//------[S4]-------+
    12.                         ^                         |
    13.                         |                         |
    14.                         +-------------------------+
    15.  
    16.  
    The S01,S11 outputs from the controller are inputs to the decoder.
    The initial state sets up the default values, and waits for the 0,0 inputs.
    The values of the inputs change the states. You will need to determine what
    the decoder outputs will be for each state. It will probably be

    Code ( (Unknown Language)):
    1.  
    2. 0,1,0,0,
    3. 0,0,0,1
    4. 1,0,0,0
    5. 0,0,1,0
    6.  
    but not necessarily.

    If this was real-life, I would feed the controller output into a
    74xx138 or 74xx139 1 of n decoder, and rearrange the lights so
    the proper one would light.

    Code ( (Unknown Language)):
    1. OUTPUT connected to
    2.         LED
    3.   1      1
    4.   2      3
    5.   3      0
    6.   4      2
    --Rich
     
Loading...