Ic counting for cd4029

Discussion in 'Digital Circuit Design' started by cliff33, Aug 13, 2016.

  1. cliff33

    Thread Starter New Member

    Aug 11, 2016
    4
    0
    Hi everyone:
    Could someone tell me how to change the start sequence on my cd4029 counter.

    I would like the count to start at one and not at zero.
    Would greatly appreciate any help on this.
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,136
    1,786
    You tie the Jam Inputs {J4, J3, J2, J1} = {L, L, L, H}, Take PE (PRESET ENABLE) Low and clock the data through to the outputs.
     
  3. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,516
    1,246
    IF you are asking about having the counter roll over to 1 instead of 0 when up-counting, then set the Jam inputs as above, and tie the Carry Out to the Preset Enable through an inverter. I have not tried this, but the timing diagram on the data sheet indicates that it might work.

    Wait. The Preset Enable input is asynchronous, which makes this harder to do...

    ak
     
  4. hp1729

    Well-Known Member

    Nov 23, 2015
    1,939
    218
    How about a CD4029 exercise?
     
  5. cliff33

    Thread Starter New Member

    Aug 11, 2016
    4
    0
    Thanks for that info Papabravo, but couldn't get it to work.
    I am trying to get ONLY 8 pulses coming through and then continually reverse.
    I don't care if it's 0 to 7 or 1 to 8. I have the bi-directional working ok using a flip-flop to trigger up/down.
    With the nine pulses I get: 0000,0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000, 0111, 0110, 0101 etc.
     
  6. cliff33

    Thread Starter New Member

    Aug 11, 2016
    4
    0
    Thanks AnalogKid:
    Tried your idea and it does work except that at the count of one, it stays for two pulses.
    I'm using a de-bouncing switch for manual pulsing.
     
  7. cliff33

    Thread Starter New Member

    Aug 11, 2016
    4
    0
    Good suggestion hp1729.
    I'll be doing this exercise to learn more about this chip.
    Thanks
     
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