this paper we present a family of Mixed-signal (mixed analog/digital) synthesis tools being developed at the University of Cincinnati. The VASE (VHDL-AMS Synthesis Environment) project involves the development of a vertically integrated synthesis environment centered around the emerging VHDL-AMS standard for specification of analog and mixed signal systems. The unique contributions of this research include the following:

A persistent criticism of analog synthesis techniques is that they cannot cope with the complexity of realistic industrial designs, especially system-level designs. We show how recent advances in simulation-based synthesis can be augmented, via appropriate macromodeling, to attack complex analog blocks. To support this claim, we resynthesize from scratch, in several different styles, a complex equalizer/filter block from the frontend of a commercial ADSL CODEC, and verify by full simulation that it matches its original design specifications. As a result, we argue that synthesis has significant potential in both custom and analog IP reuse scenarios.

Synthesis of mixed-signal designs from behavioral specifications must address analog-digital partitioning. In this paper, we investigate the issues in mixed-signal behavioral partitioning and design space exploration for signal-processing systems. We begin with the system behavior specified in an intermediate format called the Mixed Signal Flow Graph, based on the time-amplitude characterization of signals. We present techniques for analog-digital behavioral partitioning of the MSFG, and performance estimation of the technology-mapped analog and digital circuits. The partitioned solution must satisfy constraints on imposed by the target field programmable mixed-signal architecture on available configurable resources, available data converters, their resolution and speed, and IO pins. The quality of the solution is evaluated based on two metrics, namely feasibility and performance. The former is a measure of the validity of the solution with respect to the architectural constraints. The latter measures the performance of the system based on bandwidth/speed and noise.

This paper defines a VHDL-AMS subset for behavioral synthesis of analog systems. The subset includes language constructs for describing most of the functional aspects pertaining to analog systems. Besides, these constructs can be implemented with electronic circuits. Functional aspects, which can be expressed with the subset, relate to two interacting parts. The analog part continuously processes analog signals, while the control part generates control signals for configuring the flow of signals in the analog part. However, some language constructs have to be constrained or augmented, so that they become effective for synthesis. To motivate that constructs in the subset can be synthesized, we present, by means of an example, how VHDL-AMS programs are compiled into an intermediate format. The intermediate format can be either directly mapped to components from a component library, or used for further synthesis-related optimization steps. Finally, we discuss a complete experiment for spe...

This paper presents a heuristic technique for automatically generating different architectures for an analog system. The architecture generator (AG) starts from a signal-flow graph (SFG) specification of a system. The AG iteratively produces various system net-lists as distinct implementations can realize the signal processing and flow in an SFG. Area and power for resulting net-lists are rapidly evaluated with High-Level Performance Estimator (HPE), a simplified estimation module. The AG algorithm is simple to implement. It does not require an extensive pattern library as traditional AG techniques do.

this paper we present a family of Mixed-signal (mixed analog/digital) synthesis tools being developed at the University of Cincinnati. The VASE (VHDL-AMS Synthesis Environment) project involves the development of a vertically integrated synthesis environment centered around the emerging VHDL-AMS standard for specification of analog and mixed signal systems. The unique contributions of this research include the following: