Patent ID: 8242790

Claim:
A sensor system for protecting products and technology from reverse engineering by detecting attempts to probe electronic circuitry, comprising: an integrated circuit including an I/O pin, the integrated circuit being a programmable logic device including an impedance sensor and electronic circuitry in communication with the I/O pin, wherein the impedance sensor is completely integrated inside the integrated circuit and is implemented using the programmable logic device, the impedance sensor is electrically linked to the electronic circuitry, the impedance sensor detecting interaction of probe devices with the electronic circuitry for the purpose of reverse engineering the electronic circuitry; the impedance sensor includes: an exciter causing an oscillation that is a function of the exciter and impedance of the electronic circuitry, the exciter is completely integrated inside the integrated circuit and is implemented using the programmable logic device; an impedance counter linked to the exciter, a count rate of the impedance counter is a function of the impedance of the electronic circuitry due to the fact that oscillation frequency generated by the exciter is also a function of the impedance of the electronic circuitry; an impedance register storing the binary count value from the impedance counter, wherein after the impedance counter data is transferred into the impedance register, the data is referred to as impedance data; a reference oscillator monitoring count rate of the impedance counter; and a sensor evaluation system compares the impedance value to threshold values to determine if a significant change has occurred, and when changes have occurred this is indicative of abnormal behavior and may be indicative of tampering relating to the evaluation of the electronic circuit for the purpose of reverse engineering.