Programmable sensor for on-line checking of signal integrity in FPGA-based systems subject to aging effects

In current nanometer technologies, aging effects (due for instance to Negative Bias Thermal Instability) may appear after relatively short operating times, compared to the expected lifetime of circuits, even for relatively short-cycle consumer electronics. Therefore, there is an increasing need for on-chip aging monitoring. This paper presents a programmable aging sensor that can be embedded in FPGA-based designs, using standard resources available in those devices. The sensing principle is to monitor performance degradation over time. Depending on whether dynamic or static aging effects are dominant, the sensor can operate continuously or be only activated at some time intervals. Given the reduced amount of resources required by the sensor, it can be instantiated not only in the critical paths of a circuit, but also in those that may be identified to be more likely affected by aging affects. Experimental results are presented to demonstrate the performance of the proposed sensor.