Title :
Energy optimization of subthreshold-voltage sensor network processors
Author :
Nazhandali, Leyla ; Zhai, Bo ; Olson, Javin ; Reeves, Anna ; Minuth, Michael ; Helfand, Ryan ; Pant, Sanjay ; Austin, Todd ; Blaauw, David
Author_Institution :
Michigan Univ., USA
Abstract :
Sensor network processors and their applications are a growing area of focus in computer system research and design. Inherent to this design space is a reduced processing performance requirement and extremely high energy constraints, such that sensor network processors must execute low-performance tasks for long durations on small energy supplies. In this paper, we demonstrate that subthreshold-voltage circuit design (400 mV and below) lends itself well to the performance and energy demands of sensor network processors. Moreover, we show that the landscape for microarchitectural energy optimization dramatically changes in the subthreshold domain. The dominance of leakage power in the subthreshold regime demands architectures that i) reduce overall area; ii) increase the utility of transistors; while iii) maintaining acceptable CPI efficiency. We confirm these observations by performing SPICE-level analysis of 21 sensor network processors and memory architectures. Our best sensor platform, implemented in 130nm CMOS and operating at 235 mV, only consumes 1.38 pJ/instruction, nearly an order of magnitude less energy than previously published sensor network processor results. This design, accompanied by bulk-silicon solar cells for energy scavenging, has been manufactured by IBM and is currently being tested.
Keywords :
CMOS integrated circuits; SPICE; memory architecture; microprocessor chips; optimisation; program processors; sensor fusion; solar cells; 130 nm; 235 mV; CMOS; CPI efficiency; SPICE-level analysis; bulk-silicon solar cell; leakage power; memory architecture; microarchitectural energy optimization; sensor network processor; subthreshold-voltage circuit design; Application software; CMOS process; Circuit synthesis; Computer networks; Manufacturing; Memory architecture; Microarchitecture; Performance analysis; Photovoltaic cells; Sensor systems and applications;
Conference_Titel :
Computer Architecture, 2005. ISCA '05. Proceedings. 32nd International Symposium on
Print_ISBN :
0-7695-2270-X
DOI :
10.1109/ISCA.2005.26