Run-time adaptive performance compensation using on-chip sensors

This paper discusses run-time adaptive performance control with on-chip sensors that predict timing errors. The sensors embedded into functional circuits capture delay variations due to not only die-to-die process variation but also random process variation, environmental fluctuation and aging. By compensating circuit performance according to the sensor outputs, we can overcome PVT worst-case design and reduce power dissipation while satisfying circuit performance. We applied the adaptive speed control to subthreshold circuits that are very sensitive to random variation and environmental fluctuation. Measurement results of a 65nm test chip show that the adaptive speed control can compensate PVT variations and improve energy efficiency by up to 46% compared to the worst-case design and operation with guardbanding.