Behavioral Modeling for High-Level Synthesis of Analog and Mixed-Signal Systems from VHDL-AMS

High-level synthesis is highly demanded for managing the complexity of analog and mixed-signal system designs. However, synthesis methods are currently in their infancy. The absence of a high-level specification notation is an important limitation for the development of efficient synthesis methods. This paper presents a behavioral model and a VHDL-AMS subset for high-level synthesis of analog and mixed-signal systems. The model (named aBlox) offers a composition semantics for functionality description, and an orthogonal, declarative mechanism for expressing the performance requirements of a system. The model was developed after analyzing a large number of systems for telecommunication, signal processing, control engineering, and analog computing. The model expresses the meaning of (1) analog and digital data, (2) continuous and event-driven functionality (behavior), (3) analog performance attributes, and (4) analog-digital interactions. The aBlox model served as a foundation for defining a semantically sound VHDLAMS subset for synthesis. Also, the VHDL-AMS subset was identified so that its constructs can be mapped to architectures of circuits. We introduced several restrictions to the VHDL-AMS instructions, such that their semantics matches to that of the aBlox model. To motivate the usefulness of the model and the VHDL-AMS subset, we presented a case study that used VHDLAMS inputs.