Dynamic voltage scaling algorithm for fixed-priority real-time systems using work-demand analysis

Dynamic Voltage Scaling (DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. Unlike dynamic-priority real-time scheduling for which highly effective DVS algorithms are available, existing fixed-priority DVS algorithms are less effective in energy efficiency because they are based on inefficient slack estimation methods. This paper describes an efficient on-line slack estimation heuristic for the rate-monotonic (RM) scheduling. The proposed heuristic estimates the slack times using the short term work-demand analysis. The DVS algorithm based on the proposed heuristic is also presented. Experimental results show that the proposed DVS algorithm reduces the energy consumption by 25∼42% over the existing rate-monotonic DVS algorithms.