Accession Number : ADA440182


Title :   Dynamic I/O Power Management for Hard Real-Time Systems


Corporate Author : DUKE UNIV DURHAM NC DEPT OF ELECTRICALAND COMPUTER ENGINEERING


Personal Author(s) : Swaminathan, Vishnu ; Chakrabarty, Krishnendu ; Iyengar, S S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a440182.pdf


Report Date : Jan 2005


Pagination or Media Count : 7


Abstract : Power consumption is an important design parameter for embedded and portable systems. Software-controlled (or dynamic) power management (DPM) has recently emerged as an attractive alternative to inflexible hardware solutions. DPM for hard real-time systems has received relatively little attention. In particular, energy-driven I/O device scheduling for real-time systems has not been considered before. We present the first online DPM algorithm, which we call Low Energy Device Scheduler (LEDES), for hard real-time systems. LEDES takes as inputs a predetermined task schedule and a device-usage list for each task and it generates a sequence of sleep/working states for each device. it guarantees that real-time constraints are not violated and it also minimizes the energy consumed the I/O devices used by the task set. LEDES is energy-optimal under the constraint that the start times of the tasks are fixed. We present a case study to show that LEDES can reduce energy consumption by almost 50%.


Descriptors :   *ALGORITHMS , *SCHEDULING , *ENERGY CONSUMPTION , *INPUT OUTPUT DEVICES , REAL TIME , OPERATING SYSTEMS(COMPUTERS) , CENTRAL PROCESSING UNITS


Subject Categories : Operations Research
      Computer Hardware


Distribution Statement : APPROVED FOR PUBLIC RELEASE