SRAM-cells Reproducibility Metrics for Physical Unclonable Function Applications

This work-in-progress characterizes the start-up value reproducibility proposing a combination of mismatch metrics suitable for reliability estimation during design phases. is to provide a metrics-based description of each SRAM instance useful to designers of SRAM-based PUF systems, improving the uniformity and reliability of the final design and enabling prediction of the effects of pre-characterization design decisions after system fabrication. We evaluate the metrics results and analyze the start-up values reproducibility considering different external perturbation sources like several power supply ramp up times, previous internal values in the bit-cell, and different temperature scenarios. The characterization metrics can be exploited to estimate the number of most suitable SRAM cells for use in PUF implementations that can be expected from specific PUF design, predict the number of suitable cells evolution against electronic degradation processes and define the range of operating conditions tolerating noisy environments effects.