基于POOSL的系统级建模及性能分析

System-level Modeling and Performance Analysis Based on POOSL

针对嵌入式系统设计复杂性的不断增加以及设计周期逐渐缩短的问题,提出一种系统级设计方法．在系统的软/硬件实现之前建立系统的抽象模型,对系统定性和定量属性进行评估,确定设计方案的可行性．阐述了系统级设计方法,以滑动窗口协议为例,基于系统级的设计方法建立了该协议的POOSL模型,定量分析了窗口大小、帧丢失率和超时间隔等参数对协议性能的影响．结果表明,该方法能在系统设计的早期阶段评估系统的设计方案．

Due to the increasing complexity of the embedded systems, the gap between a product idea and a working system expands rapidly. To manage the complexity and shorten the design cycles, this article puts forward a method of system-level design, which focuses on the development of executable models which allow qualitative and quantitative properties to be analyzed before the system is actually realized in terms of hardware and software components. System-level design methods should be based on well-defined modeling languages to support creating executable models that properly represent the system to be designed. The parallel objectri- ented specification language （POOSL） is a system-level modeling language for complex embedded systems. It has been demonstrated to be very effective for modeling systems such as internet router and network processor. A system-level model for SWP is built by using POOSL. Through the simulation of the model, results of the quantitative performance analysis on the influence of the parameters such as the window size, the packet size and the timeout period are given. Furthermore, some key parameters can be determined during the earliest phases of the design process. The system-level method can assess the schemes in the earliest phases of system design.