Exploiting synchronous and asynchronous DVS for feedback EDF scheduling on an embedded platform

Contemporary processors support dynamic voltage scaling (DVS) to reduce power consumption by varying processor voltage/frequency dynamically. We develop power-aware feedback-DVS algorithms for hard real-time systems that adapt to dynamically changing workloads. The algorithms lower execution speed while guaranteeing timing constraints. We study energy consumption for synchronous and asynchronous DVS switching on a PowerPC board. Energy, measured via data acquisition, is reduced up to 70% over naive DVS for our feedback scheme with 24% peak savings over previous algorithms. These results, albeit differing in quantity, confirm trends observed under simulation. They are the first of their kind on an embedded board.