US Patent 7685488 Circuit interconnect testing arrangement and approach therefor

Logic level crossings in an integrated circuit are detected. According to an example embodiment, a reset signal is provided to a flip-flop (314) as a function of a logic level of an integrated circuit. A logic level crossing condition of the integrated circuit is indicated as a function of the reset condition of the flip flop. In one implementation, the flip-flop is reset when the logic level is different than an expected logic level. In another implementation, a pair of flip-flops (414, 418) are implemented such that only one flip-flop is reset at a particular logic level; if the logic level crosses, both flip-flops are reset. The aforesaid condition of both flip-flops being reset is used to indicate the logic level crossing.