A self-aware processor SoC using energy monitors integrated into power converters for self-adaptation

Yildiz Sinangil, Sabrina M. Neuman, Mahmut E. Sinangil, Nathan Ickes, George Bezerra, Eric Lau, Jason E. Miller, Henry Hoffmann, Srinivas Devadas, Anantha P. Chandrakasan

Abstract: This paper presents a self-aware processor with energy monitoring circuits that can measure actual energy consumption of the key blocks. The monitors are embedded into on-chip DC/DC converters and generate results within 10% of accuracy with minimal power (<;0.1%) and area (<;1%) overhead. Our system, which is implemented in 0.18μm technology, is designed to be voltage scalable from 1.8V down to 0.6V. Low-voltage SRAM operation is made possible through the use of 8T bit-cells and write-assists. The d-caches are designed to be re-configurable in associativity and size to adapt to compute- versus cache-bound phases of applications. Cache configuration is performed in <; 3 clock cycles including tag invalidation. These hardware features enable a software self-aware computation engine (SEEC) to dynamically adapt the processor to meet performance and energy goals. Measurement results show that up to 8.4× energy savings can be achieved with DVFS and self-adaptation.