Packing sporadic real-time tasks on identical multiprocessor systems

In real-time systems, in addition to the functional correctness recurrent tasks must fulfill timing constraints to ensure the correct behavior of the system. Partitioned scheduling is widely used in real-time systems, i.e., the tasks are statically assigned onto processors while ensuring that all timing constraints are met. The decision version of the problem, which is to check whether the deadline constraints of tasks can be satisfied on a given number of identical processors, has been known NP-complet

Performance Evaluation of Components Using a Granularity-based Interface Between Real-Time Calculus and Timed Automata

To analyze complex and heterogeneous 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 fine models to work with event streams at coarse granularity. We perform analysis of the component at multiple coarse granularities and then based on RTC theory, we derive lower and upper bounds on arrival patterns of the fine output streams using the causality closure algorithm. Our framework can help to achieve tradeoffs between precision and analysis time.Comment: QAPL 201

Interactive schedulability analysis

10.1145/1324969.1324976Transactions on Embedded Computing Systems7

Model-based development and verification of control software for electric vehicles

Most innovations in the automotive domain are realized by electronics and software. Modern cars have up to 100 Elec-tronic Control Units (ECUs) that implement a variety of control applications in a distributed fashion. The tasks are mapped onto different ECUs, communicating via a het-erogeneous network, comprising communication buses like CAN, FlexRay, and Ethernet. For electric vehicles, soft-ware functions play an essential role, replacing hydraulic and mechanic control systems. While model-based software development and verification are already used extensively in the automotive domain, their importance significantly in-creases in electric vehicles as safety-critical functions might no longer rely on mechanical (fall-back) solutions. The need for reducing costs, size, and weight in electric vehicles has also resulted in a considerable interest in topics such as the consolidation of ECUs as well as efficient implementation of control software. In this paper we discuss two broad issues related to model-based software development and verifica-tion in electric vehicles. The first is concerned with how to ensure that model-level semantics are preserved in an imple-mentation, which has important implications on the verifi-cation and certification of control software. The second issue is related to techniques for reducing the computational and communication demands of distributed automotive control algorithms. For both these topics we provide a broad intro-duction to the problem followed by a discussion on state-of-the-art techniques

Cache-aware optimization of BAN applications

10.1007/s10617-009-9045-3Design Automation for Embedded Systems133159-178DAES