Making an UP/Down Counter MOD20 with 2x74191

Discussion in 'Homework Help' started by blank, Nov 25, 2008.

  1. blank

    Thread Starter Member

    Apr 26, 2008
    I would like to make an UP/DOWN Counter MOD20 with 2x74191

    my thought is to make a MOD10 and a MOD2 so i can count to 20

    but really i dont understand the inputs and the outputs of 74191 !!!

    this is a preview of 74191: [​IMG]
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    If you just want to go 0 - 19, then a flip flop can do for the 10's digit.

    Can you be specific about what you don't understand?