Power Optimization for Embedded System Idle Time in the Presence of Periodic Interrupt Services

Generally, there are periodic interrupt services in the real-time embedded systems even when the system is in the idle state such as the periodic clock tick interrupts. To minimize the idle power, power management therefore should consider the effect of periodic interrupt services. In this paper, we deal with this problem considering two scenarios. In case the periodic interrupt cannot be disabled, we first model the power consumption and then propose static and dynamic approaches for the optimal frequency selection to save idle power. On the other hand, in case the periodic interrupt can be disabled, we propose an approach to delay the interrupt service until the next task is released so that the processor can stay in low power mode for longer time. The proposed approaches are implemented in a real-time OS and its effectiveness has been validated by theoretical calculations and actually measurements on an embedded processor.