Dynamic Voltage Scaling for Real-Time Systems with System Workload Analysis

Zhe ZHANG  Xin CHEN  De-jun QIAN  Chen HU  

IEICE TRANSACTIONS on Electronics   Vol.E93-C    No.3    pp.399-406
Publication Date: 2010/03/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E93.C.399
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Electronic Circuits
real-time,  dynamic voltage scaling,  power management,  probability distribution,  

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Dynamic Voltage Scaling (DVS) is a well-known low-power design technique, which adjusts the clock speed and supply voltage dynamically to reduce the energy consumption of real-time systems. Previous studies considered the probabilistic distribution of tasks' workloads to assist DVS in task scheduling. These studies use probability information for intra-task frequency scheduling but do not sufficiently explore the opportunities for the system workload to save more energy. This paper presents a novel DVS algorithm for periodic real-time tasks based on the analysis of the system workload to reduce its power consumption. This algorithm takes full advantage of the probabilistic distribution characteristics of the system workload under priority-driven scheduling such as Earliest-Deadline-First (EDF). Experimental results show that the proposed algorithm reduces processor idle time and spends more busy time in lower-power speeds. The measurement indicates that compared to the relative DVS algorithms, this algorithm saves energy by at least 30% while delivering statistical performance guarantees.