ReSCALE: Recalibrating sensor circuits for aging and lifetime estimation under BTI

Bias temperature instability (BTI) induced delay shifts in a circuit depend strongly on its operating environment. While sensors can capture some operating parameters, they are ineffective in measuring vital performance shifts due to changes in the workloads and signal probabilities. This paper determines the delay of an aged circuit by amalgamating more frequent measurements on ring-oscillator sensors with infrequent online delay measurements on a monitored circuit to recalibrate the sensors. Our approach reduces the pessimism in predicting circuit delays, thus permitting lower delay guardbanding overheads compared to conventional methods.