Unified Power Management Framework for Portable Media Devices

Power management is one of the key design challenges in the design of portable multimedia devices (PMD). Existing power management techniques are limited to hardware based DVFS (dynamic schemes) and do not take into account application states and many usage scenarios. In this correspondence, a new unified power management framework (UPMF) is proposed which describes a software architecture for a unified hardware and software controlled power management. The framework provides a set of rules for classifying the several devices on a PMD into device classes. Each of these device classes has a set of well-defined states based on the application state. The power management framework contains a power manager module that monitors the application and maintains the states of the devices and based on the power management strategy, controls the states of the devices. The proposed UPMF is very simple to implement and is well suited to handle power management strategies for several classes of applications. Performance of this proposed scheme for a portable media player and recorder device is also presented.