Integrated circuit test mode securisation method by intrusion detection

摘要

The circuit has configurable cells (2a, 2w, 2z) with multiplexers and flip-flops and adopting operating and test modes based on control signals on control conductors. A spy circuit delivers an output signal adopting states representing no fault/attempted intrusion, based on whether a logic combination of signals passing through the conductors relates to a combination of control signals visible in an operating state.