Voltage Assignment and Loop Scheduling for Energy Minimization while Satisfying Timing Constraint with Guaranteed Probability

Low energy consumption is an important problem in real-time embedded systems and loop is the most energy consuming part in most cases. Due to the uncertainties in execution time of some tasks, this paper models each varied execution time as a probabilistic random variable. We use rotation scheduling and DVS (Dynamic Voltage Scaling) to minimize the expected total energy consumption while satisfying the timing constraint with a guaranteed confidence probability. Our approach can handle loops efficiently. In addition, it is suitable to both soft and hard real-time systems. And even for hard real-time, we have good results.