GENUS : a generic component library for high level synthesis

This report describes the organization of GENUS, a generic component library for high level synthesis. Generic components and instances in GENUS are organized into hierarchical classes, with the component type stored at the root of the hierarchy, and particular instances stored at the leaves. This permits a consistent representation of generic components which may be used by a variety of synthesis and analysis tools. The appendix contains the description of the GENUS generator library

Generic Pipelined Processor Modeling and High Performance Cycle-Accurate Simulator Generation

Detailed modeling of processors and high performance cycle-accurate simulators are essential for today's hardware and software design. These problems are challenging enough by themselves and have seen many previous research efforts. Addressing both simultaneously is even more challenging, with many existing approaches focusing on one over another. In this paper, we propose the Reduced Colored Petri Net (RCPN) model that has two advantages: first, it offers a very simple and intuitive way of modeling pipelined processors; second, it can generate high performance cycle-accurate simulators. RCPN benefits from all the useful features of Colored Petri Nets without suffering from their exponential growth in complexity. RCPN processor models are very intuitive since they are a mirror image of the processor pipeline block diagram. Furthermore, in our experiments on the generated cycle-accurate simulators for XScale and StrongArm processor models, we achieved an order of magnitude (~15 times) speedup over the popular SimpleScalar ARM simulator.Comment: Submitted on behalf of EDAA (http://www.edaa.com/

Behavioral modeling of DRACO : a peripheral interface ASIC

This paper describes the behavioral modeling of DRACO, a peripheral interface Application Specific Integrated Circuit (ASIC) developed by Rockwell International for numerical control applications. The behavioral model was generated from a data sheet of the fabricated chip, which primarily described the chip's input-output functionality, physical and operational characteristics, and a functional block diagram. The data sheet contained very little abstract behavioral information. This report describes the abstract behavioral model of the DRACO chip, and uses flowcharts and VHDL to capture the behavior. The behavioral model was developed through reverse engineering of the data sheet description, supplemented by further consultation with designers of the DRACO ASIC at Rockwell Intemational. The report describes typical behavioral test sequences that were applied to the DRACO VHDL model to verify its correctness. The appendices contain the original DRACO datasheet and the VHDL code used to capture DRACO's behavior

Bridging high-level synthesis to RTL technology libraries

The output of high-level synthesis typically consists of a netlist of generic RTL components and a state sequencing table. While module generators and logic synthesis tools can be used to map RTL components into standard cells or layout geometries, they cannot provide technology mapping into the data book libraries of functional RTL cells used commonly throughout the industrial design community. In this paper, we introduce an approach to implementing generic RTL components with technology-specific RTL library cells. This approach addresses the criticism of designers who feel that high-level synthesis tools should be used in conjunction with existing RTL data books. We describe how GENUS, a library of generic RTL components, is organized for use in high-level synthesis and how DTAS, a functional synthesis system, is used to map GENUS components into RTL library cells

Benchmarking for high-level synthesis

This paper discusses issues in benchmarking for synthesis, and suggests techniques for the comparison of benchmark descriptions, the synthesis tools used, as well as the synthesized designs finally generated. We propose a classification scheme for the assumptions made for the comparison of different synthesis tools, and present an Assumptions Chart that can be used to visualize different benchmarks, tools and synthesis results. We illustrate application of this Assumptions Chart using synthesis experiments that were conducted on some sample High-Level Synthesis Workshop bench-marks

EXTEND-L : an input language for extensible register transfer compilation

This report discusses the model and input language for EXTEND, a synthesis system that permits extensible register transfer synthesis. EXTEND-L fills the need for a language that bridges the gap between existing behavioral input descriptions, which are too abstract, and structural schematics, which cannot capture the high-level behavior. The report first discusses previous work in behavioral synthesis and summarizes the deficiencies of these behavioral specifications. The report then describes the proposed langauge in detail, and concludes with a few examples that show its utility

Harmonic scheduling of linear recurrences in digital filter design

Linear difference equations involving recurrences are fundamental equations that describe many important signal processing applications. For many high sample rate digital filter applications, we need to effectively parallelize the linear difference equations used to describe digital filters - a difficult task due to the recurrences inherent in the data dependences. We present a novel approach, Harmonic Scheduling, that exploits parallelism in these recurrences beyond loop-carried dependencies, and which generates optimal schedules for parallel evaluation of linear difference equations with resource constraints. This approach also enables us to derive a parallel schedule with minimum control overhead, given an execution time with resource constraints. We also present a Harmonic Scheduling algorithm that generates optimal schedules for digital filters described by second-order difference equations with resource constraints

EXEL : a language for interactive behavioral synthesis

This paper describes a new input language for behavioral synthesis called EXEL. EXEL is a powerful language that permits the user to specify partially designed structures in the language. It employs a mixed graphic/textual user interface to enhance user interactivity. EXEL's design model is comprehensive: it permits specification of synchronous and asynchronous behavior, and allows specification of general timing constraints. A flexible type construct permits the user to define operators and components to be used in the description. Finally, it simplifies compilation by using a small set of constructs for specifying timing and asynchronouos behavior. The compiler for EXEL runs on SUN-3 workstations and is written in C and SUNVIEW