How can I set the starter number of ripple counter

Discussion in 'The Projects Forum' started by Axess, May 12, 2011.

  1. Axess

    Thread Starter New Member

    May 12, 2011
    2
    0
    How can I set a starter number of 4-bit binary ripple counter

    I can create a 4-bit ripple counter (That can count 0000-1111 (0-15)) by JK flip-flop
    but I can't set a starter number of it.

    By default, when reset is 1. the counter print 0000
    and I change reset switch to 0, the counter count up from 0000 to 1111 and then change to 0000 and count up again.

    1. If I WANT to set a starter to 1010 and then count from 1010 to 1111 then change to 0000 and STOP. How can I do it?
    2. If I WANT to set a starter to 1010 and then count from 1010 to 1111 then change to 0000 and CONTINUE running from 0000-1111 and loop again and again. How can I do it?

    Can you show me the FULL circuit with pin name on each device & description?
    Assume that, I use LogicWorks and simulate the circuit.
    Thank you very much.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    You don't specify what model of JK flipflop you're using.
    A 4000-series CMOS 4027 dual JK flipflop has SET and RESET inputs.

    For normal operation, they must be held at a logic low level; to SET or RESET the Q output, you would raise one of them high momentarily.

    But, this sounds like a homework question assigned by an instructor/teacher/professor. Is it?
     
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
    395
    Check a 4029, presettable 4 bit binary counter + other functions.
     
  4. Axess

    Thread Starter New Member

    May 12, 2011
    2
    0
    So, I create a topic in a wrong forum. OTL

    -----
    I use xilinx to apply with board CPLD XC9572XL
    my jk flip-flop has
    - CLOCK
    - J
    - K
    - RESET
    - SET
    - Q (Output)
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Well, I don't have LogicWorks nor Xilinx.

    But, you would need to add some logic to RESET just the outputs that you want low, and SET the outputs that you want high, whenever you wish to re-initialize the count.
     
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