Design logic circut

Discussion in 'Homework Help' started by katarina, Apr 15, 2013.

  1. katarina

    Thread Starter New Member

    Apr 15, 2013
    "In this exercise you have to make a combinatorial digital circuit. The circuit has a bit width of 2 bit. The circuit also has two control signals A and B which decide the function of the circuit according to TABLE 1(attachement). The signals “in” and “out” are on 2's complement form."

    I am completely lost on where to start here. First of all the table makes no sense to me, what does "Out = In" actually mean, and "Out = In-1" etc. perhaps that can give me some kind of clue on where to start. I read up on the basics of logic circuits and know what an AND, OR, NOT, NAND, NOR and XOR gate is, but I am not sure how all that helps me solve this exercise.

    Thank you all!
  2. absf

    Senior Member

    Dec 29, 2010
    You have to design the inside of the black box as attached so that:

    When func_A=0,
    and func_B=1,
    If input="11", output should be="10" (Out = In -1).

  3. katarina

    Thread Starter New Member

    Apr 15, 2013
    Thank you! That made it way more clear, I am going to try to continue further from here on and see how far I get :)