The Schedule Strategy With Energy Constraint In Embedded Real-time System

With the thorough study and broad applications of embedded technology, embedded systems have been widely accepted and brought into effect in people's daily life. In respect that most of these implementations of embedded system just referred to require high real-time constraint, as the core software of the embedded real-time system, the improving and developing of embedded real-time OS is now facing a challenge by complicated and rigorous restriction condition, in which, the conflict of energy and performance is one of the important problems it should solved out.Along with development of hardware technology, the Dynamic power management and the Dynamic voltage scaling make it possible to solve the energy cost for embedded systems. But these technologies, which sacrificed the performance, exposed a shortage in real-time application area. The schedule strategy with energy constraint in embedded real-time system satisfies the timing constraints and reduces the system energy cost at the same time, which means a lot to the embedded real-time system development.ARTs-OS is an embedded real-time operating system developed by Huaxiang Software Research and Development Centre. Aiming at solving the energy wastage in embedded real-time OS, ARTs-OS designed and realized its own real-time Dynamic Energy Management subsystem based on the DPM and DVS technology.The DEM of ARTs-OS is divided into two parts. The Dynamic Energy Management module is based on Task Management and the Dynamic Energy Management module is based on Device Management. Together with the Task Management subsystem, DEM-TM dynamically changes the work voltage/mode of the processor under the analysis of the system load information and the task's real-time constraint. DEM-DEV scouts and analyses the usage circs of the devices, and then changes the working mode for devices.The real-time dynamic energy management subsystem of ARTs-OS helps it achieves distinct energy save effect.