Modeling distributed real-time applications with specification PEARL

Abstract

The methodology of hardware/software co-design of embedded control systems with Specification PEARL is presented. Hardware and software are modeled with the language Specification PEARL, which has its origins in standard Multiprocessor PEARL. Its usefulness is enhanced for modeling hierarchical and asymmetrical multiprocessor systems, and by additional parameters for schedulability analysis. Graphical symbols are introduced for its constructs to enable graphical modeling while maintaining the semantical background. It is meant to be a superlayer for programs, based on the PEARL programming model. To model program tasks, Timed State Transition Diagrams have been defined. The model of a co-designed system is verified for feasibility with co-simulation. The resulting information should be used when considering changes in a current design with the goal of producing a temporally feasible model. To support dynamic re-configurations, configuration management is introduced into the models. Since UML is becoming a de facto standard also for designing embedded control systems, and since Timed State Transition Diagrams and State Chart Diagrams share great similarity, an interface of the methodology to UML 2 is defined, using UML's extension mechanisms.

A reconfiguration pattern for distributed embedded systems

“…The Specification PEARL hardware/software co-design methodology [5] originates from Multiprocessor PEARL, which has been extended in a manner foreseen by the standard. The methodology features: -extended constructs to describe hardware configurations, -extended constructs to describe software configurations, -construct attributes extended with timing information (where applicable), -graphical representations of constructs to enable graphical modelling, -constructs to specify communication and its characteristics (peripheral and process connections, physical and logical connections, transmission protocols), as well as -constructs to specify both conditions and methods for carrying out dynamic reconfigurations.…”

“…With all this in mind, the hardware/software co-design methodology and its associated specification language Specification PEARL have been developed to model distributed embedded systems [5]. From our experience, the reconfiguration actions [6], which are mostly considered atomic, are not simple operations and may incorporate multiple levels of system architecture.…”

A Domain-specific Language for Real-time Dynamical Systems Emulation on a Microcontroller

“…There are several languages for expressing dynamical systems (see for example (Elmqvist, 1977;Gumzej, 2007;Ermentrout, 2012). However, it would be convenient to have a language which is rich enough to express a wide variety of dynamical systems and simple enough to be easily processed so that a senior student or control engineer can understand the process.…”