In one embodiment, a device comprises: a first die having disposed thereon a first plurality of latches wherein ones of the first plurality of latches are operatively connected to an adjacent one of the first plurality of latches; and a second die having disposed thereon a second plurality of latches wherein ones of the second plurality of latches are operatively connected to an adjacent one of the second plurality of latches. Each latch of the first plurality of latches on said first die corresponds to a latch in the second plurality of latches on said second die. Each set of corresponding latches are operatively connected. A scan path comprises a closed loop comprising each of said first and second plurality of latches. One of the second plurality of latches is operatively connected to another one of the second plurality of latches via an inverter.