随着手机、PDA等便携电子设备的功能日益丰富,用户对更高性能和更长工作时间的要求成为越来越明显的矛盾。电池技术在近期不会出现较大的突破,因而电源管理正在成为便携式设备设计人员遇到的最主要技术挑战之一。目前系统设计人员广泛采用一些设计技巧来降低系统功耗,如:降低工作电压,优化系统和CPU As mobile phones, PDAs and other portable electronic devices become more and more rich, the requirements of users for higher performance and longer working hours become more and more obvious contradictions. Battery technology in the near future will not be a major breakthrough, so power management is becoming one of the most important technical challenges encountered by portable device designers. At present, system designers widely adopt some design techniques to reduce system power consumption, such as: reducing operating voltage, optimizing system and CPU