Retention state-aware energy management for efficient nonvolatile processors

Harvested energy is intrinsically unstable and program execution will be interrupted frequently. To solve this problem, nonvolatile processor (NVP) is proposed because it can back up volatile state before the system energy is depleted. However, the backup and the recovery processes also consume non-negligible energy and delay program progress. To improve the performance of NVP, retention state has been proposed recently which can enable a system to retain the volatile data to wait for power resumption instead of saving data immediately. The objective of this paper is to forward program execution progress as much as possible by exploiting the retention state. Compared to the instant backup scheme, preliminary evaluation results report that power failures can be reduced by 81.6% and computation efficiency can be increased by 105%.