Regarding 4th pin of 7447

Discussion in 'Homework Help' started by Jayasurya Pitchuka, Jul 22, 2016.

  1. Jayasurya Pitchuka

    Thread Starter New Member

    Apr 14, 2016
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    0
    If i need a double digit display (eg:54) can anyone explain why we are connecting the ~RBO of preceeding digit to the next digit's ~RBI. Please explain the internal mechanism ( I know that its for supressing trailing zeroes ). And also i have done the simulation and when im trying to run it the preceeding digit is not displaying (eg: in 37 only 7 is being displayed the other 7 segment display doesn't work ) why is this happening ?
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,135
    1,786
    I'm confused. In information processing we never blank trailing zeros, only leading zeros. Trailing zeros are significant digits, leading zeros are not. What's going on here?
     
  3. Jayasurya Pitchuka

    Thread Starter New Member

    Apr 14, 2016
    4
    0
    sorry dude its leading.... my mistake
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,135
    1,786
    So correct me if I am wrong but connect the RBI of the least significant digit to a logic 1 because you never want to blank the least significant digit. Connect the remaining inputs low so the digits will blank when they are zero. Won't that do the job?
     
  5. WBahn

    Moderator

    Mar 31, 2012
    17,715
    4,788
    Think of the names. RBO - Ripple Blanking Output; RBI - Ripple Blanking Input.

    There's no way we can tell you what's going on in a simulation when you don't tell us how you have connected your circuit. Don't make us guess -- engineering is not about guessing.
     
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