XFVHDL4: A hardware synthesis tool for fuzzy systems

This paper presents a design technique that allows the automatic synthesis of fuzzy inference systems and accelerates the exploration of the design space of these systems. It is based on generic VHDL code generation which can be implemented on a programmable device (FPGA) or an application specific integrated circuit (ASIC). The set of CAD tools supporting this technique includes a specific environment for designing fuzzy systems, in combination with commercial VHDL simulation and synthesis tools. As demonstrated by the analyzed design examples, the described development strategy speeds up the stages of description, synthesis, and functional verification of fuzzy inference systems.Comunidad Europea FP7-IST-248858Ministerio de Ciencia e Innovación TEC2008-04920Junta de Andalucía P08-TIC-0367

ASIC design of an IIR digital filter: Using Mentor Graphics DSP Station Tools

Automation in VLSI design is a powerful way to simplify the VLSI layout process and will allow for faster time to market for integrated circuit designs. One means of automation is VHDL, a hardware description language for integrated circuit designs. A structured VHDL description can be used to describe the hardware design at the logic-gate level, and automated software is available that will use this gate-level design to generate the VLSI layout. A more recent type of automation occurs at a level above this. The Mentor Graphics DSP Station tools use a high-level algorithmic description to generate the gate-level VHDL description. These tools are especially intended for applications in digital signal processing (DSP), providing simulation tools particularly geared toward DSP algorithms. One application of digital signal processing is an infinite impulse response (IIR) filter. With the use of the Mentor Graphics tools, a digital filter was designed from a set of original specifications down to the silicon level. N-well 1.2 micron CMOS technology with two metal layers and one polysilicon layer was used to implement the filter layout. Using the 1.2 micron CMOSN standard cell library, the final VLSI layout measured 7.315 mm x 7.213 mm, containing approximately 25,700 transistors

Synthesis from specifications : basic concepts

The need has evolved for a synthesis tool at the computer system level. SpecSyn is one such tool. Basically, it will view the world as a set of chips communicating via protocols. Thus, an abstract specification would get synthesized into a set of one or more interconnected chips. From that point, detail is added to each chip's specification until its structure is synthesized or it is determined that a prefabricated chip similar in functionality can be used.Features of such a tool include executable specifications from which to synthesize, constraint driven partitioning of the specifications into components (chips) and synthesis of interfaces between them, translation into VHDL and synthesis into VHDL structures of micro-architectural components, and the use of other tools (e.g. MILO, a micro-architecture and logic optimizer, and LES, a layout expert system) to evaluate the quality of the chip layout generated from VHDL description.A major component of SpecSyn is SpecCharts, a high level specification language amenable to system level synthesis, able to represent designs from system to register transfer levels. The language consists of a hierarchy of states, represented in combined graphical and textual form, at the same time catering to the expression of concurrent behavior and specification of constraints. With it we have specified several Intel chips as well as higher level systems, and have found it to be quite powerful and easy to use.SpecSyn will have a graphical interface, from which the user can at any time view or edit a SpecChart, translate to VHDL and simulate, view statistics provided by estimators (such as area, speed, and pins), store and retrieve SpecCharts, apply basic Spec Chart operations, as well as apply the partitioning algorithms or interface synthesizer. Providing access to a wide range of tools, having a single language represent the design throughout the synthesis process, and having user specified constraints allow the user to have varying amounts of control over the synthesis process

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

VHDL synthesis system (VSS) : user's manual, version 5.0

This report provides instructions for installing and using the VHDL Synthesis System (Version 5.0). VSS is a high level synthesis sytem that synthesizes structures from an abstract description, written with VHDL behavioral constructs. The system uses components from a generic component library (GENUS). The output of VSS is in structural VHDL and could be verified using a commercial VHDL simulator. The designer can control the synthesis process by providing different resource constraints to the system. VSS is also capable of producing different architectures which can be selected by the designer

VSS : a VHDL synthesis system

This report describes a register transfer synthesis system that allows a designer to interact with the design process. The designer can modify the compiled design by changing the input description, selecting optimization and mapping strategies, or graphically changing the generated design schematic. The VHDL language is used for input and output descriptions. An intermediate representation which incorporates signal typing and component attributes simplifies compilation and facilitates design optimization. The compilation process consists of two phases. First, a design composed of generic components is synthesized from the input description. Second, this design is translated into components from a particular library by a mapper and optimized by a logic optimizer. Redesign to new technologies can be accomplished by changing only the component library

A design representation model for high-level synthesis

Design tools share and exchange various types of information pertaining to the design. The identification of a uniform design representation to capture this information is essential for the development of a successful design environment. We have done an extensive study on the representation needs of existing database tools in the UCI CADLAB; examples of which are graph compilers for high-level hardware specifications, state schedulers, hardware allocators, and microarchitecture optimizers. The result of this study is the development of a design representation model that will serve as a common internal representation (DDM) for all system and behavioral synthesis tools. DDM thus builds the foundation for a CAD Framework in which design tools can communicate via operating on this common representation. The design information is composed of three separate graph models: the conceptual model, the behavioral model and the structural model. The conceptual model (represented by a Design Entity Graph) captures the overall organization of the design information, such as, versions and configurations. The behavioral model (represented by an Augmented Control/Data Flow Graph) describes the design behavior. The structural model (represented by an Annotated Component Graph) captures the hierarchical data path structure and its geometric information. In this paper, we define the last two graph models. They both capture the actual design data of the application domain. Since VHDL has gained increasing popularity as hardware description language for synthesis, we give numerous examples throughout this report that show how the proposed design representation model can be used to represent VHDL specifications