Distributed DVFS using rationally-related frequencies and discrete voltage levels

Abstract--As a replacement for the fast-fading GloballySynchronous model, we have defined a flexible design style called GRLS, for Globally-Ratiochronous, Locally-Synchronous, which does not rely on global synchronization and is based on rationallyrelated clock frequencies derived from the same source. The design style also provides a set of supply voltages for each island to choose from. In this paper, we present the implementation details of the clock and voltage generation and distribution architecture necessary to enable Distributed DVFS. Considering a 90 nm implementation of a realistic system, we then calculate the overheads and the energy benefits compared to mesochronous and GALS approaches, quantitatively showing a considerable reduction in energy consumption compared to both solutions. Compared to GALS, the area overhead and the time necessary to change the voltage-frequency operating point are reduced several orders of magnitude.

• Type: Journal
• Year: 2010
• Where: ISLPED
• Authors: Jean-Michel Chabloz, Ahmed Hemani
• Keywords: Design Style, Fast-fading Globallysynchronous Model, Hardware, ISLPED 2010, Rationallyrelated Clock Frequencies