Dynamic Voltage Scaling in hard real-time systems considering precedence and exclusion relations

DVS (dynamic voltage scaling) has been adopted as an effective technique for reducing energy consumption in mobile embedded systems. Since reducing CPU supply voltage affects maximum CPU frequency, several concerns (e.g. deadline missing) may arise when adopting DVS in systems that contain hard real-time constraints. Although several scheduling approaches have been developed to address voltage scaling in time-critical systems, inter-task relations, such as precedence and exclusion relations, have been neglected. This work presents a method for hard real-time systems scheduling with DVS considering precedence and exclusion relations. The proposed work adopts a formal model based on time Petri nets in order to find a feasible schedule using a pre-runtime approach that satisfies timing and energy constraints.