Intra-operation Dynamic Voltage Scaling

Embedded peripheral devices are often specified with a range of performance characteristics that are determined by their supply voltage. Recent research explored the benefits of modulating peripheral supply voltage with task-level granularity. With Intra-Operation Dynamic Voltage Scaling (IODVS), we further reduce the energy consumption of peripheral devices by modulating the peripheral supply voltage at critical states occurring during operation of the peripheral device. IODVS is designed to have minimal impact on CPU utilization through the use of a lookup table that designates an ideal voltage on a per-state basis. IODVS is unique in that during high-performance states such as data-transmission, peripherals can have the high supply voltage required to reduce overall energy-delay product. Likewise, during low-performance states such as mandatory delays, the system decreases peripheral domain voltage thus reducing energy consumption without adversely affecting performance or correctness. We demonstrate this method on various peripherals common to wireless sensor nodes and have found total energy savings of up to 40%.