ONODERA Hidetoshi Kyoto Univ., Graduate Sch. Of Informatics. Professor, 工学研究科, 教授 (80160927)
TSURUTA Naoyuki Faculty of Engineering, Assistant Prof., 工学部, 助教授 (60227478)
SUETSUGU Tadashi Faculty of Engineering, Assistant Prof., 工学部, 助教授 (60279255)
(a) Development of a Energy-Recovering Processor Architecture and its prototype chip implementation. We investigated a new concept of Energy-Recovering Processor Architecture and presented techniques for its implementation. Due to adiabatic charge-recovering and instruction and, data reuse, the architecture lowers the energy consumption by almost two orders of magnitude in comparison to the traditional processor design. To evaluate the architecture, a prototype LSI chip have been designed and fabricated.
(b) Development of Architectural Techniques for Reducing Transition Activity of Processing Hardware.Several new schemes to minimize switching activity of functional units, and register files by datadriven operand encoding, adaptive bit-width compression, operand transformation, bypassing, etc. have been proposed. Unlike conventional techniques, these methods can dynamically disable the hardware bits whose values remain unchanged, thus reducing unnecessary signal variations as much as ha]f without affecting the processing accuracy. The schemes are simple and easy in implementation.
(c) Development of Architectural Techniques for Variable Voltage Reduction of System Memory. New circuit techniques for adaptive voltage reduction in instruction issue queue, data and instruction caches have been proposed. In contrast to existing design approaches, the methods dynamically adjust the supply voltage to the level of instruction parallelism (issue queue) as well as the locality of accesses (caches), reducing the energy dissipation in these units by a factor of two without any impact on performance and very small area overhead.