Research Of The Hardware-Software Partitioning And Task Scheduling Algorithm Based On Reconfigurable Embedded System

In recent years, embedded systems are integrating more and more functions, this has brought the demand of higher performance and faster market progress.With large scale integrated circuit design and manufacturing technology advancing and reconfigurable hardwares such as FPGA rapidly developing,especially with the emergence of dynamic partial reconfiguration technique, even more reconfigurable hardwares have been applied to embedded systems. The development of reconfiguration technique blurs the traditional boundary between hardware and software, makes hardware likely to be software,and increase the flexibility in system design and implement.However, reconfigurable architecture brings challenge in embedded system hardware and software co-design methodology at the same time it becomes the important developing direction in embedded system. The traditional methods of Hardware-Software Partitioning do not apply to reconfigurable embedded system.According to new features like: dynamic reconfiguration, time cost of reconfiguration and others, which is brought about by reconfigurable hardware logic,this dissertation brings forward a new task partitioning and task scheduling method based on analyzing and summarizing existing hardware-software partitioning algorithm. This method can be used in Hardware-Software Partitioning of Reconfigurable Embedded Systems. Using this method, a structure model is established. Then a big application is decomposed into many sub-tasks which had restricted relations and appropriate granularity, and according to the restricted relations of every sub-task executed early and late, a directed acyclic graph which had the meaning of restricted relations is drew. Afterward according to resource restrict and other conditions of reconfigurable system, using of genetic / tabu search (GATS) integration strategy, the specific application which described by task graph is mapped to the hardware and software platform, so the process of task assignment of hardware-software partitioning is achieved. Finally the order and start time of various tasks and communications which was assigned to each processing unit in Reconfigurable System is determined by used configuration prefetching and scheduling strategy. Using this method the results of the division can meet the control and data dependencies and ultimately the performance of the system would be improved.At last, this dissertation builds an experimental platform and writes a test program. The test results present that GATS is much better than GA and TS in the solution accuracy, and configuration prefetching and scheduling can effectively reduce the time of the system configuration and preparation, thus reducing the overall completion time of task graph.This method can effective finish the space-time mapping from application task graph to a reconfigurable system effectively.