A Framework for the Design of Mixed-Signal Systems with Polymorphic Signals Rüdiger Schroll *1) Wilhelm Heupke *1) Klaus Waldschmidt *1) Christoph Grimm *2) *1) Technische Informatik *2) Institut für Mikroelektronische Systeme University of Frankfurt a.M. Vienna University of Technology Frankfurt, Germany Vienna, Austria http://www.ti.cs.uni-frankfurt.de/ http://www.ict.tuwien.ac.at/ Abstract— Embedded systems are very heterogeneous: They include software, analog/RF, digital hardware, and non-electronic components such as sensors or actuators. To handle the high complexity, an efficient and flexible simulation methodology is needed. Therefore we present a framework in SystemC-AMS that enables communication of different models of computation (MoCs) via polymorphic signals. Thereby mixed-level simulation, successive refinement and the evaluation of synthesized components are supported. Key-Words: polymorphic signals, design, systems, refinement, communication, mixed-signal, SystemC-AMS 1 1.1 1.2 Introduction Overview Nearly all embedded designs involve to some extent analog hardware. Current hardware platforms permit the fast and accurate digital processing of analog signals using DSPs or FPGAs, while the non ideal properties of analog circuits are becoming more dominant by shrinking, lower voltages, higher temperatures and higher signal frequencies. Therefore, pure analog circuits are combined with digital systems that realize dedicated tasks in digital circuits, compensate the errors and deviations of analog circuits by e.g. calibration, or augment analog circuits with new features such as on-line diagnosis or fail-safe properties. Furthermore embedded systems use an increasing number of sensors, actors or even RF interfaces to react dynamically to their environment. The increasing functional integration in combination with adaptive behavior of software components, FPGAs or parameterizable analog switched capacitor circuits creates many opportunities for circuit design and applications. However, the resulting design alternatives can only be analyzed with appropriate EDA software. SystemC(-AMS) provides appropriate means for specification, modeling, simulation, and synthesis of adaptive and re-configurable mixed-signal systems. In this context we want to support the system design and provide a framework that allows designers an easy exchange of different models, e.g. to exchange a transfer function against a netlist without modifications of the other models and signals in the system. Furthermore it supports both top down and bottom up design: • In a top down design flow, it supports the performance exploration of different architectures, and • In a bottom up design flow, it provides a test bench for the system verification of refined or synthesized components of the system. Section 2 describes the refinement methodology and the evaluation of synthesized dimensioned circuits in a system test bench. In section 3 the communication principle of the polymorphic signal is explained. Section 4 gives an idea of time savings using polymorphic signals for system design. Examples are presented in section 5 and section 6 concludes the paper. Requirements and approach In model based design, designers use different pre-defined schemes for communication and synchronization. These are called “models of computation” (MoCs). Different MoCs are used, depending on the architecture to be modeled: E.g. This work has been supported within the BMBF/edacentrum project ‘SAMS’ [9]. Proceedings of the 10th WSEAS International Conference on SYSTEMS, Vouliagmeni, Athens, Greece, July 10-12, 2006 (pp465-470)