Section: New Results

The CESAR demonstrator and reference technology platform

Participants : Huafeng Yu, Yue Ma, Loïc Besnard, Thierry Gautier, Jean-Pierre Talpin, Paul Le Guernic.

The design of embedded systems from multiple views and heterogeneous models is ubiquitous in avionics as, in particular, different high-level modeling standards are adopted for specifying the structure, hardware and software components of a system. The system-level simulation of such composite models is necessary but difficult task, allowing to validate global design choices as early as possible in the system design flow. Inspired by the Ptolemy [40] , MoBIES [31] , SML-Sys [47] , etc., we propose an approach to the issue of composing, integrating and simulating heterogeneous models in a system co-design flow [21] . First, the functional behavior of an application is modeled with synchronous data-flow and Statechart diagrams using Simulink/Gene-Auto [54] , [55] . The system architecture is modeled in the AADL standard [52] . These high-level, synchronous and asynchronous, models are then translated into a common model, based on a polychronous model of computation, allowing for a Globally Asynchronous Locally Synchronous (GALS) interpretation of the composed models. This translation is implemented as an automatic model transformation within Polychrony. Simulation, including profiling, value change dump demonstration [24] , Syndex adequation [43] , etc., is carried out based on the common model within Polychrony.

Polychrony has been integrated to the Reference Technology Platform (RTP) V2 and V3 of CESAR to serve as a framework for co-modeling and architecture exploration. ModelBus [49] is used for the integration of Polychrony into the RTP. ModelBus [25] , an integration platform based on Service-Oriented Architecture (SOA), connects different services offered by tools connected to ModelBus. In the demonstration, we participated in the pilot application of Sub-Project 3 (SP3), whose aim is to use the RTP to define a complete software design flow for the doors management system (DMS) of an Airbus A350 in the framework of ModelBus. In the pilot application of the DMS, functional components are modeled in the synchronous model of computation of Simulink, whereas the architecture is modeled in the asynchronous model of computation of AADL[14] , [18] . These high-level models are transformed into Signal programs via SME models. Additional models, which are used in the simulation of a closed system, are coded manually in Signal and synchronously composed with the Signal programs transformed from Simulink and AADL models. Finally, C or Java code is generated from Signal programs. Simulation can then be carried out for the purpose of performance evaluation and VCD (Value Change Dump) based demonstration in RTP V2. In RTP V3, Syndex adequation is also integrated to demonstrate real-time scheduling and distribution. Our whole model transformation and simulation chain has been implemented with Galileo Eclipse and attached to ModelBus as a provider of registered remote service. This demonstration also shows the integration of Polychrony with other tools, such as OSATE (AADL), Simulink, Gene-Auto, TimeSquare, ATL, Kermeta, etc.