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TICK Research team

Theory and Practice of Synchronous Reactive Systems

  • Leader : Robert De simone
  • Research center(s) : CRI Sophia Antipolis - Méditerranée
  • Field : Communicating systems
  • Theme : Embedded systems and mobility

Team presentation

The TICK research team conducts research on the general theory of synchronous reactive systems, with particular emphasis on the Esterel formalism. Esterel is an imperative language dedicated to the specification and programming of embedded system applications, and in particular hardware or software controllers of various kinds.

Research topics on semantic issues inside the realm of synchronous reactive systems allowed definition of efficient algorithmic methods for compilation, optimisation and verification of programs. Current research follows this path, with a strand on bridging the gap between synchronous formalisms and their strong mathematical foundation on one hand, and more conventional software engineering pratices on the other hand.

Esterel is now being marketed by Esterel Technologies, a french company started as an INRIA spin off. Longstanding collaborations are continued with companies such as Dassault Aviation, Thales, Intel Co., and Texas Instruments.

Research themes

Esterel semantics was provided in two ways: the dynamic behavioural semantics provided a translation into Mealy automata by means of SOS rules; the hardware interpretation was based on a translation into seqential circuit netlists. In both cases the underlying mathematical model, automata or circuits, could be used for analytic methods in the fields of compilation, optimisation, verification, and in the case of Esterel for specific constructive causality analysis.

In current work we focus on analysis methods at higher descriptive level, closer to the program syntax and more oriented towards software compilation. We stress the importance of the hierarchical modular structure of programs for efficient analysis techniques at various stages of program design. Ongoing studies focus on :

  • Efficient software compilation and program optimisation;
  • Modular model-checking;
  • Implementation on distributed architectures and relaxation of full synchrony hypothesis;
  • Connection with Hardware Description Languages;
  • Reverse engineering and inclusion of other reactive synchronous components inside an Esterel larger system;
  • Codesign issues and mixed compilation;
  • Connection with object-oriented design and component-based programming (this is mostly done in fact by the Sports team from the university of Nice, with whom we maintain very close collaborations).

International and industrial relations

  • We keep close ties with the Esterel Technologies company, as well as some of their industrial partners (see above);
  • We are active in the international ``Synchronous Reactive'' community, including the french research teams developping the Signal and Lustre formalisms;
  • we collaborate inside the Syntel RNRT project with the Thales and Cadence companies.
  • We are part of the ARTIST/HaRT european network consortium.

Keywords: Causality Concurrency Co-operation Reactivity Synchronization Functional language Semantics Synchronous language Real-time Asynchronous parallelism Program verification