An Approximate Maximum Common Subgraph Algorithm for Large Digital Circuits

This paper presents an approximate Maximum Common Subgraph (MCS) algorithm, specifically for directed, cyclic graphs representing digital circuits. \ud Because of the application domain, the graphs have nice properties: they are very sparse; have many different labels; and most vertices have only one predecessor. The algorithm iterates over all vertices once and uses heuristics to find the MCS. It is linear in computational complexity with respect to the size of the graph. Experiments show that very large common subgraphs were found in graphs of up to 200,000 vertices within a few minutes, when a quarter or less of the graphs differ. The variation in run-time and quality of the result is low

Timing verification of dynamically reconfigurable logic for Xilinx Virtex FPGA series

This paper reports on a method for extending existing VHDL design and verification software available for the Xilinx Virtex series of FPGAs. It allows the designer to apply standard hardware design and verification tools to the design of dynamically reconfigurable logic (DRL). The technique involves the conversion of a dynamic design into multiple static designs, suitable for input to standard synthesis and APR tools. For timing and functional verification after APR, the sections of the design can then be recombined into a single dynamic system. The technique has been automated by extending an existing DRL design tool named DCSTech, which is part of the Dynamic Circuit Switching (DCS) CAD framework. The principles behind the tools are generic and should be readily extensible to other architectures and CAD toolsets. Implementation of the dynamic system involves the production of partial configuration bitstreams to load sections of circuitry. The process of creating such bitstreams, the final stage of our design flow, is summarized

Automatic mapping of graphical programming applications to microelectronic technologies

Adaptive computing systems (ACSs) and application-specific integrated circuits (ASICs) can serve as flexible hardware accelerators for applications in domains such as image processing and digital signal processing. However, the mapping of applications onto ACSs and ASICs using the traditional methods can take months for a hardware engineer to develop and debug. In this dissertation, a new approach for automatic mapping of software applications onto ACSs and ASICs has been developed, implemented and validated. This dissertation presents the design flow of the software environment called CHAMPION, which is being developed at the University of Tennessee. This environment permits high-level design entry using the Cantata graphical programming software fromKRI. Using Cantata as the design entry, CHAMPION hides from the user the low-level details of the hardware architecture and the finer issues of application mapping onto the hardware. Validation of the CHAMPION environment was performed using multiple applications of moderate complexity. In one case, theapplication mapping time which required six weeks to perform manually took only six minutes for CHAMPION, yet comparable results were produced. Furthermore, the CHAMPION environment was constructed such that retargeting to a new adaptive computing system could be accomplished in just a few hours as opposed to weeks using manual methods. Thus, CHAMPION permits both ACSs and ASICs to be utilized by a wider audience and application development accomplished in less time

Partitioning of large HDL ASIC designs into multiple FPGA devices for prototyping and verification

The ASIC (Application specific Integrated Circuit) designs grow continuously bigger and bigger. This causes dramatic increase in the simulation run time. It is very hard to simulate these designs because the simulation time has risen from hours to days and weeks. Hardware Embedded Simulation (HES) is a technology that facilitates incremental design verification of ASICs. The FPGAs (Field Programmable Gate Arrays) can play an important role in ASIC design cycle. But it is not possible to fit an entire ASIC design into a single FPGA device. This problem can be solved by partitioning the given design into multiple small size designs (modules) and fitting those modules into multiple FPGAs. The purpose of my thesis is to take a large RTL (Register Transfer Level) design of an ASIC into consideration, write and test the software ( C code) practically to synthesize each top level module and analyze the size of each module in terms of number of CLBs (Configurable Logic Blocks), I/Os, flip-flops, latches and apply the algorithm to partition it automatically into minimum number of FPGAs

IP Delivery for FPGAs Using Applets and JHDL

This paper introduces an FPGA IP evaluation and delivery system that operates within Java applets. The use of such applets allows designers to create, evaluate, test, and obtain FPGA circuits directly within a web browser. Based on the JHDL design tool, these applets allow structural viewing, circuit simulation, and netlist generation of applicationspecific circuits. Applets can be customized to provide varying levels of IP visibility and functionality as needed by both customer and vendor

USING LOGIC SYNTHESIS TOOLS FOR TEXAS INSTRUMENTS FP GAs

High density PLDs (Programmable Logic Devices) and FP GAs (Field-Programmable Gate Arrays) are becoming more and more popular in the field of logic design. Their ultimate advantages - no NRE (Non-REcurring) costs, fast time-to-market, in-house design, etc. - are being combined with ever increasing speeds and densities. Up to now the tradi- tional FPGA design technique has been schematics. But hardware complexity has outrun schematics with chips so complex that the graphical representation of the circuit shows only a web of connectivity, not the functionality of the design. For this reason more and more engineers are turning to Hardware Description Languages (HDL) for digital design. The prospect of using Logic Synthesis Tools is one of the main reasons which make HDLs attractive for designers. These tools take a behavioural, or other type of HDL description, and produce a technology specific net list for an FPGA or for another type of ASIC. The effectiveness of the Logic Synthesis Tools is a key factor in deciding against or in favour of HDLs and synthesis. The synthesis powers of two programs were tested and compared using three sample designs. The meaning of FPGAs, HDLs and Logic Synthesis are ex- plained in more detail in the first chapters of the article. The results of logic synthesis are in the second part. The source codes, command line arguments and batch (or script) files used are also given

Qucs workbook

This document is intended to be a work book for RF and microwave designers.Our intention is not to provide an RF course, but some touchy RF topics. The goal is to insist on design rules and work flow for RF design using CAD programs. This work flow will be handled through different subjects

STRICT: a language and tool set for the design of very large scale integrated circuits

PhD ThesisAn essential requirement for the design of large VLSI circuits is a design methodology which would allow the designer to overcome the complexity and correctness issues associated with the building of such circuits. We propose that many of the problems of the design of large circuits can be solved by using a formal design notation based upon the functional programming paradigm, that embodies design concepts that have been used extensively as the framework for software construction. The design notation should permit parallel, sequential, and recursive decompositions of a design into smaller components, and it should allow large circuits to be constructed from simpler circuits that can be embedded in a design in a modular fashion. Consistency checking should be provided as early as possible in a design. Such a methodology would structure the design of a circuit in much the same way that procedures, classes, and control structures may be used to structure large software systems. However, such a design notation must be supported by tools which automatically check the consistency of the design, if the methodology is to be practical. In principle, the methodology should impose constraints upon circuit design to reduce errors and provide' correctness by construction' . It should be possible to generate efficient and correct circuits, by providing a route to a large variety of design tools commonly found in design systems: simulators, automatic placement and routing tools, module generators, schematic capture tools, and formal verification and synthesis tools

A High-level Methodology for Automatically Generating Dynamic Partially Reconfigurable Systems using IP-XACT and the UML MARTE Profile

International audienceDynamic Partial Reconfiguration (DPR) has been introduced in recent years as a method to increase the flexibility of FPGA designs. However, using DPR for building com- plex systems remains a daunting task. Recently, approaches based on Model-Driven Engi- neering (MDE) and UML MARTE standard have emerged which aim to simplify the design of complex SoCs, and in some cases, DPR systems. Nevertheless, many of these approaches lacked a standard intermediate representation to pass from high-levels of descriptions to ex- ecutable models. However, with the recent standardization of the IP-XACT specification, there is an increasing interest to use it in MDE methodologies to ease system integration and to enable design flow automation. In this paper we propose an MARTE/MDE approach which exploits the capabilities of IP-XACT to model and automatically generate DPR SoC designs. We present the MARTE modeling concepts and how these models are mapped to IP-XACT objects; the emphasis is given to the generation of IP cores that can be used in the Xilinx EDK (Embedded Design Kit) environment, since we aim to develop a complete flow around their Dynamic Partial Reconfiguration design flow. Finally, we present a case study integrating the presented concepts, showing the benefits in design efforts compared with a purely VHDL approach and using solely EDK. Experimental results show a reduction of the design efforts required to obtain the netlist required for the DPR design flow from hours required in VHDL and Xilinx EDK, to less the one hour and minutes for IP integration