Pspice question, please help me~!

Discussion in 'General Electronics Chat' started by kaneneville, Mar 7, 2009.

  1. kaneneville

    Thread Starter New Member

    Mar 7, 2009

    the picture above is a ripple carry adder. When I apply the logic level to the adder, the digital signal coming out from the signal generator is "X". I added a voltage probe to it and it shows two red lines. Anyone know what happened?