Charge recycling from idle circuits for improved energy efficiency of multi-voltage systems

Abstract

A method for the delivery of power to subthreshold (sub-Vt) circuits uses unused current during idle-mode operation of super-threshold (super-Vt) circuits is used to supply sub-Vt circuits. Algorithmic and circuit techniques use dynamic management of idle cores when reusing the leakage current of the idle cores. A scheduling algorithm, longest idle time-leakage reuse (LIT-LR) enables energy efficient reuse of leakage current, which generates a supply voltage of 340 mV with less than ±3% variation across the tt, ff, and ss process corners. The LIT-LR algorithm reduces the energy consumption of the switch and the peak power consumption by, respectively, 25% and 7.4% as compared to random assignment of idle cores for leakage reuse. Second, a usage ranking based algorithm, longest idle time-simultaneous leakage reuse and power gating (LIT-LRPG) enables simultaneous implementation of power gating (PG) and leakage reuse in a multiprocessor system-on-chip (MPSoC) platform.

Dependencies are inferred from the claim text.