Granularity-based Interfacing between RTC and Timed Automata Performance Models

To analyze the complex and heterogenous real-time embedded systems, recent works have proposed interface techniques between real-time calculus (RTC) and timed automata (TA), in order to take advantage of the strengths of each technique for analyzing various components. But the time to analyze a state-based component modeled by TA may be prohibitively high, due to the state space explosion problem. In this paper, we propose a framework of granularity-based interfacing to speed up the analysis of a TA modeled component. First, we abstract the fine models to work with event streams at coarse granularities. Then based on the RTC theory, we develop a formal mathematical algorithm to derive lower and upper bounds on the arrival patterns of the fine output streams, by analyzing the component for multiple runs at coarse granularities. These bounds may be tighter than those simply implied by the results analyzed from the abstracted models. Our framework can help to achieve the tradeoffs between the precision and the analysis time.