dynamic i/o power management for hard real-time systems
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 L ow E nergy D evice S cheduler (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\%.
dynamic real-time system real-time systems design embedding portability hardware attention device scheduling online algorithm task sequence constraint energy case studies energy consumption software optimality power-management dynamic power management