Need help with Multiplexers and Decoders

Discussion in 'Homework Help' started by loofa, Feb 27, 2013.

  1. loofa

    Thread Starter New Member

    Feb 27, 2013
    I need help with question 3 and 4. (File attached)
    For question 3 I already finished my k-map and found the F=AC'D'+A'BD+ABC+A'B'CD' I don't know how to use two 3:8 line decoders to produce a 4:16 line decoder.

    For question 4 I'm totally lost, if you can get me started that would be great.
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    Your assignment is past due.

    Can you show your work for the 7 segment question, and question number 5?

    Also, show how far you got with number 4.

    On number 4, start by making the truth table.
  3. WBahn


    Mar 31, 2012
    Now please attach the file that shows the work you have done thus far on both of them. Don't worry about it being correct, just show your best attempt.

    If you have two 3:8 line decoders that have an enable input and the output of all eight lines are taken LO when disabled, how could you use a single signal to control which decoder was enabled (and to make sure that only one of them is enabled at a time) and how could you combine the two outputs to make a single output that matched the output of the enabled decoder?

    "Totally" lost? As in, "I don't know what a 2-to-1 MUX thingy is" kind of lost?

    If your not that lost, then start by building a truth table for F(A,B,C) and you can start that by building a truth table for the signal connecting the two muxes.