Design And Implementation Of Low Power Consumption In Linux-based Embedded System

With the development of Embedded Technology, embedded products have been able to meet users'needs in function, but the power consumption is becoming an urgent problem. Low power consumption should be considered in both electrical characteristics and software control.This thesis will introduce a low power management way in which the system power consumption is controlled by software. First put forward a set of solution which can effectively control the power consumption of the system according to the current power technology and actual hardware platform. The system is on base of ARM9 processor and Linux operating system. The purpose of the system lies on five aspects, firstly the system can judges the system load intellectually, secondly the system can receive the external trigger in order to make the system sleep, thirdly reduce the power dissipation, fourthly the system can be awakened into normal running state under the external trigger or increasing load, last but not the least, the system will provide different depth sleep function according to actual requirement, in each sleep state, the running status of each device will be different, so the power consumption will also be different. The detailed realization is divided into two parts, system control and hardware device control. System control decides if the system is needed to run into a lower power state by analyzing the system running status, which contains the CPU running time of user progress and kernel thread, and system requirements. Hardware device control involves each peripheral device. Meanwhile, implement the system of rapid awakening via adding module in startup code. According to this solution, the power consumption can achieve the power dissipation requirement of different depth of sleep. And the lowest power dissipation can drop to less than 15% of normal operation consumption. Although this design proposal is in view of specific hardware platform, the design philosophy can be used on other embedded platform perfectly.