DPU(data process unit,数据处理单元)是嵌入式系统中的一个典型组件,被广泛应用于太空领域,它在层次化的嵌入式系统架构中起到承上启下的作用。保证这类安全攸关系统可靠性的主要方法包括冗余容错、测试和仿真。近年来,形式化方法作为确保可靠性的一种重要补充,得到了广泛的关注。BIP(behavior interaction priority)是一个通用的系统级形式化建模框架,支持层次化和模块化,包含一套支持建模、模拟和验证的工具集。给出了一种基于BIP框架对DPU进行系统级建模与验证的一般方法,总结了一套使用BIP框架对DPU建模应遵循的原则及技巧。以航天领域一个真实DPU系统为例,系统地对方法、原则和技巧进行了介绍。通过该方法,找出了使用传统方法难以发现的错误。实践表明,该方法具有很好的可复用性和可扩展性,是确保系统可靠性的有益补充。
DPU (data process unit) is a typical component for embedded systems. It' s widely used in space application. It obtains data from sensors in lower level, processes data and then sends result back to master computer in higher level. There are redundancy, testing and simulation to ensure the reliability of the DPU system. BIP ( behavior interaction priority) is a general formal modeling framework for embedded system. It supports hierarchy and module structure, contains a toolset including modeling, simulation and verification tools. This paper presented a set of general methods and principles for modeling DPU system using BIP framework and verifying properties on the BIP model. It took a real DPU system from space as example and succeeded in finding some bugs, which was difficulty for traditional way. The method was reusable and extendable. It' s useful to ensure the reliability of the system.