A Model-Based Design Process for the SegBus Distributed Architecture

We discuss a design process for a custom distributed platform, namely the SegBus segmented bus architecture. The main emphasis of this work is on how different steps of the process are interconnected and how they are supported by the associated tool chain. We place the SegBus design process in the context of the model-driven architecture (MDA) paradigm, in order to provide graphical editors that allow the editing of the specification at different abstraction levels and automated transformations that refine the specification towards implementation. We customize the Unified Modeling Language (UML) to graphically specify different artifacts produced in the process and we employ UML-based tools to implement transformations between these artifacts. In addition, we adopt as application model the packet SDF (PSDF), an extension of the synchronous data flow (SDF) diagrams. By modeling the operational semantics for the SegBus architecture, the PSDF facilitates the mapping of the application on the architecture. From the mapping process we obtain the requirements for the structural VHDL code of the application-platform instance realization and the control code for the arbiters of the architecture.