A Unifying Platform-Based Approach for the Design of Heterogeneous Systems

Last decade research on Embedded Systems has been heavily pushed by the desire to create smarter infrastructures, environments and, in general, a smarter planet. Embedded devices have been employed to perform monitoring, control and communication in order “to embed” intelligence into widely distributed physical environments. This led to the introduction of new kinds of systems such as Cyber-Physical Systems, Smart Systems, Sensory Swarm, Internet of Things and many others, all characterized by a huge amount of heterogeneity. This heterogeneity is introduced in different aspects of the design. First of all, the sub-parts composing these systems belong to different design domains, such as digital and analog HW, embedded SW, networking, mechanical or chemical processes, thus requiring heterogeneous expertise and different tools typical of every domain involved. Moreover, distinct abstraction levels must be considered during the design process and they should be brought together into unique heterogeneous models. Finally, different design concerns, such as power consumption or reliability, affect the design quality due to the often safety-critical target of these systems. To take care of this heterogeneity, many approaches have been proposed in the field of systems engineering. However, in the recent years Platform-Based Design, has emerged subsuming all the previous approaches. It aims at providing both the advantages of bottom-up and top-down approaches. It provides support for different abstraction levels, allows the separation of concerns and enhances compositional design. However, the state of the art lacks of practical frameworks and approaches that allow for both easy reuse of pre-designed components and fast system-level simulation. This thesis aims at covering this lack by proposing a unifying approach to reconcile the heterogeneous components composing a system, into a unified homogeneous executable representation. Thus, the proposed design flow starts from the high-level specification of the functionalities the system must implements, and a library of already implemented components. The models composing both the high-level specification and the library of components are heterogeneous in the sense that they can be expressed with different formalisms and languages, levels of abstraction or belonging to different design domains. Then, through a set of translation, abstraction and manipulation techniques, the approach creates a behavioral model of the system as an executable specification. This will provide fast system-level simulation, thus positively impacting all the design steps relying on simulation techniques. Automation is provided by implementing the methodologies proposed by this thesis within translation, manipulation and abstraction tools on top of a homogeneous framework called HIFSuite. The most positive consequence of the adoption of this approach is the chance to re-use typical techniques developed for the design of homogeneous devices (e.g., digital HWdesign), by extending them to the case of heterogeneous systems.