Papers Published

1. Swaminathan, V; Chakrabarty, K; Iyengar, SS, Dynamic I/O power management for hard real-time systems, Hardware/Software Codesign Proceedings of the International Workshop (January, 2001), pp. 237-242, ACM Press [doi] .
   (last updated on 2022/12/30)

   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 by 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%.