Research On Power Management Mechanism Based On Embedded System

With the widely applying of embedded systems, the performance of embedded systems has been improved rapidly. But the battery’s power consumption has become the bottleneck in the development of embedded technology. Power management technology in embedded systems has been widely concerned from academia and industry.Firstly, three kinds of existed power management mechanisms are compared and analyzed, which are APM, ACPI and DPM. APM and ACPI are strongly depend on the structure of the X86BIOS, so these two mechanisms are not suit for power management in embedded systems. If DPM defines a number of strategies and a range of operating points, then the memory usage is great, and bringing about unnecessary complexity due to its design. When the system allows two or more processes, and if these processes require a different operating state and operational status often switch, the DPM will switch to operating point frequently. Due to the process switching time is relatively short, this operation requires very high requirements of frequency conversion and transformer, frequency conversion and transformer must be completed in a very short time, most of embedded systems can not meet the requirements. Thus, these three mechanisms are not suit for most embedded systems equipments.Dynamic power management in embedded systems concerned embedded system as a state machine, defined the system into some work states, these states include normal power operation and more than one low power operation which make the system switch between several working state dynamically. As more and more systems support the frequency conversion processor, it is necessary for the power management mechanism take account the dynamic inverter technology. Past studies focused on the dynamic conversion of the processor, but neglecting the dynamic frequency conversion of other devices, such as memory frequency. In order to solve the above problem, this thesis designs a power management mechanism based on embedded systems, which supports the dynamic state switching and dynamic frequency conversion, and designs a dynamic frequency conversion strategy based on the CPU and memory operation frequency. This thesis realizes the SLEEP mode based on Linux on the platform S3C2440, which can provide some reference for the realization of power management mechanisms based on embedded systems.