Abstract— We describe dynamic voltage scaling (DVS) algorithms for real-time systems with both periodic and aperiodic tasks. Although many DVS algorithms have been developed for real-time systems with periodic tasks, none of them can be used for the system with both periodic and aperiodic tasks because of arbitrary temporal behaviors of aperiodic tasks. We propose an off-line DVS algorithm and on-line DVS algorithms that are based on existing DVS algorithms. The proposed algorithms utilize the execution behaviors of scheduling server for aperiodic tasks. Experimental results show that the proposed algorithms reduce the energy consumption by 12% and 32% under the RM scheduling policy and the EDF scheduling policy, respectively.