à This paper addresses the problem of static and dynamic variable voltage scheduling of multi-rate periodic task graphs (i.e., tasks with precedence relationships) and aperiodic tasks in heterogeneous distributed real-time embedded systems. Such an embedded system may contain general-purpose processors, field-programmable gate arrays (FPGAs) and applicationspecific integrated circuits (ASICs). Variable voltage scheduling is performed only on general-purpose processors. The static scheduling algorithm constructs a variable voltage schedule via heuristics based on critical path analysis and task execution order refinement. The algorithm redistributes the slack in the initial schedule and refines task execution order in an efficient manner. The variable voltage schedule guarantees all the hard deadlines and precedence relationships of periodic tasks. The dynamic scheduling algorithm is also based on an initially valid static schedule. The objective of the on-line scheduling algorithm is ...
Jiong Luo, Niraj K. Jha