Team Espresso

Overall Objectives
Scientific Foundations
Application Domains
New Results
Contracts and Grants with Industry
Other Grants and Activities

Section: Software

The Polychrony workbench

Participants : Loic Besnard, Thierry Gautier, Paul Le Guernic.

Polychrony is an integrated development environment and technology demonstrator consisting of a compiler, of a visual editor and of a model checker. It provides a unified model-driven environment to perform embedded system design exploration by using top-down and bottom-up design methodologies formally supported by design model transformations from specification to implementation and from synchrony to asynchrony.

Polychrony supports the synchronous, multi-clocked, data-flow specification language Signal. It is being extended by plugins to capture SystemC modules or real-time Java classes within the workbench. It allows to perform validation and verification tasks, e.g., with the integrated SIGALI model checker, the Coq theorem prover, or with the Spin model checker.

Polychrony is registered at the APP and is freely distributed from for non-commercial use. Based on the Signal language, it provides a formal framework:

  1. to validate a design at different levels,

  2. to refine descriptions in a top-down approach,

  3. to abstract properties needed for black-box composition,

  4. to assemble predefined components (bottom-up with COTS).

Figure 7. Avionics application modeling using the visual editor of the Polychrony workbench

The company TNI-Valiosys supplies a commercial implementation of Polychrony, called RT-Builder, used for industrial scale projects by Snecma/Hispano-Suiza and Airbus Industries (see ).

Polychrony is a set of tools composed of:

  1. A Signal batch compiler providing a set of functionalities viewed as a set of services for, e.g., program transformations, optimizations, formal verification, abstraction, separate compilation, mapping, code generation, simulation, temporal profiling, etc.

  2. A GUI with interactive access to compiling functionalities.

  3. The SIGALI tool, an associated formal system for formal verification and controller synthesis, jointly developed with the Vertecs project-team ( ).

Polychrony offers services for modeling application programs and architectures starting from high-level and heterogeneous input notations and formalisms. These models are imported in Polychrony using the data-flow notation Signal. Polychrony operates these models by performing global transformations and optimizations on them (hierarchization of control, desynchronization protocol synthesis, separate compilation, clustering, abstraction) in order to deploy them on mission specific target architectures. C, C++, multi-threaded and real-time Java and SynDex code generators are provided. The connection to the SynDEx distribution tool ( ) has been developed in the context of the RNTL project Acotris.


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