Rigorous system level modeling and analysis of mixed HW/SW systems

A grand challenge in complex embedded systems design is developing methods and tools for modeling and analyzing the behavior of an application software running on multicore or distributed platforms. We propose a rigorous method and a tool chain that allows to obtain a faithful model representing the behavior of a mixed hardware/software system from a model of its application software and a model of its underlying hardware architecture. The system model can be simulated and analyzed for validation of both functional and extra-functional properties. The tool chain uses DOL (Distributed Operation Layer) as the frontend for specifying the application software and hardware architecture, and BIP (Behavior Interaction Priority) as the modeling and analysis framework. It is illustrated through the construction of system models of MJPEG and MPEG2 decoder applications running on MPARM, a multicore architecture

System-Level Modeling, Analysis and Code Generation: Object Recognition Case Study

International audienceOne of the most important challenges in complex embedded systems design is developing methods and tools for modeling and analyzing the behavior of application software running on multi-processor platforms. We propose a tool-supported flow for systematic and compositional construction of mixed software/hardware system models. These models are intended to represent, in an operational way, the set of timed executions of parallel application software statically mapped on a multi-processor platform. As such, system models will be used for performance analysis using simulation-based techniques as well as for code generation on specific platforms. The construction of the system model proceeds in two steps. In the first step, an abstract system model is obtained by composition and specific transformations of (1) the (untimed) model of the application software, (2) the model of the platform and (3) the mapping between them. In the second step, the abstract system model is refined into concrete system model, by including specific timing constraints for execution of the application software, according to chosen mapping on the platform. We illustrate the system model construction method and its use for performance analysis and code generation on an object recognition application provided by Hellenic Airspace Industry. This case study is build upon the HMAX models algorithm [RP99] and is looking at significant speedup factors. This paper reports results obtained on different system model configurations and used to determine the optimal implementation strategy in accordance to hardware resources

Rigorous System Design: The BIP Approach

Rigorous system design requires the use of a single powerful component framework allowing the representation of the designed system at different levels of detail, from application software to its implementation. This is essential for ensuring the overall coherency and correctness. The paper introduces a rigorous design flow based on the BIP (Behavior, Interaction, Priority) component framework. This design flow relies on several, tool-supported, source-to-source transformations allowing to progressively and correctly transform high level application software towards efficient implementations for specific platforms

Synchronous Interface Theories and Time Triggered Scheduling

International audienceWe propose synchronous interfaces, a new interface theory for discrete-time systems. We use an application to time-triggered scheduling to drive the design choices for our formalism; in particular, additionally to deriving useful mathematical properties, we focus on providing a syntax which is adapted to natural high-level system modeling. As a result, we develop an interface model that relies on a guarded-command based language and is equipped with shared variables and explicit discrete-time clocks. We define all standard interface operations: compatibility checking, composition, refinement, and shared refinement. Apart from the synchronous interface model, the contribution of this paper is the establishment of a formal relation between interface theories and real-time scheduling, where we demonstrate a fully automatic framework for the incremental computation of time-triggered schedules

Rigorous System Level Modeling and Analysis of Mixed HW/SW Systems

International audienceA grand challenge in complex embedded systems design is developing methods and tools for modeling and analyzing the behavior of an application software running on multicore or distributed platforms. We propose a rigorous method and a tool chain that allows to obtain a faithful model representing the behavior of a mixed hardware/software system from a model of its application software and a model of its underlying hardware architecture. The system model can be simulated and analyzed for validation of both functional and extra-functional properties. The tool chain uses DOL (Distributed Operation Layer [1]) as the frontend for specifying the application software and hardware architecture, and BIP (Behavior Interaction Priority [2]) as the modeling and analysis framework. It is illustrated through the construction of system models of MJPEG and MPEG2 decoder applications running on MPARM, a multicore architecture