Embedded Systems Dynamic Power Management Study

As the technology of system integration keeps on moving forward, the functionality of embedded system becomes more and more powerful. Embedded systems are now parts of our daily life, they are used almost everywhere, like satellites, PDA, cellular phones, mp3, etc. Most power supplies of embedded systems are rechargeable batteries, though the technology of battery increases the power that battery could store, the increasing demand of people makes the power of embedded systems become more and more dissipative. So, we need effective power managing technology to save as much power as possible while still satisfies performance requirement and user experience.This thesis presents the research work of dynamic power management during author's graduate semester. This thesis first introduced the basic concepts of embedded system and dynamic power management, and the background why these technologies come forth. And then we compared several DPM approaches that are most widely used nowadays. We analyzed the power management architecture of Intel Xscale from both hardware aspect and software aspect, and using this as foundation, we designed and implemented a dynamic power management approach which could dynamically adjust power state according to current workload. We innovatively making user applications merged into DPM architecture, this feature make up the gap former DPM usually have that the information and requirements of user application are unknown to DPM approach. Finally, we presented an evaluation method which could evaluate the power saving effect of DPM approach. This evaluation method which could be merged into the real implementation of DPM architecture monitoring information it needs for analysis and analyze the effect of power saving offline. Suggestions and future work are given at the end of thesis.