Donald E. Thomas - Böcker

Recently there has been increased interest in the development of computer-aided design programs to support the system level designer of integrated circuits more actively. Such design tools hold the promise of raising the level of abstraction at which an integrated circuit is designed, thus releasing the current designers from many of the details of logic and circuit level design. The promise further suggests that a whole new group of designers in neighboring engineering and science disciplines, with far less understanding of integrated circuit design, will also be able to increase their productivity and the functionality of the systems they design. This promise has been made repeatedly as each new higher level of computer-aided design tool is introduced and has repeatedly fallen short of fulfillment. This book presents the results of research aimed at introducing yet higher levels of design tools that will inch the integrated circuit design community closer to the fulfillment of that promise. 1. 1. SYNTHESIS OF INTEGRATED CmCUITS In the integrated circuit (Ie) design process, a behavior that meets certain specifications is conceived for a system, the behavior is used to produce a design in terms of a set of structural logic elements, and these logic elements are mapped onto physical units. The design process is impacted by a set of constraints as well as technological information (i. e. the logic elements and physical units used for the design).

This text presents the IEEE 1364-2001 standard of the Verilog language. The examples in this edition have been updated to illustrate the features of the language. A cross referenced guide to these features is provided, thus, designers already familiar with Verilog can quickly learn the features. Newcomers to the language can use it as a guide for reading "old" specifications. The book should prove to be a useful resource for engineers and students interested in describing, simulating and synthesizing digital systems. It is also ready for use in university courses, having been used for introductory logic design and simulation through advanced VLSI design courses. An appendix with tutorial help and a work-along style is keyed into the introduction for new students. Material supporting a computer-aided design course on the inner working of simulators is also included. "The Verilog TM Hardware Description Language" includes a CD containing Simucad's Silos TM 2001 Verilog Simulator, examples from the book and lecture slides. The simulator is limited in the size of descriptions it will simulate. A few of the language constructs are not recognized by this version of the simulator.

Recently there has been increased interest in the development of computer-aided design programs to support the system level designer of integrated circuits more actively. Such design tools hold the promise of raising the level of abstraction at which an integrated circuit is designed, thus releasing the current designers from many of the details of logic and circuit level design. The promise further suggests that a whole new group of designers in neighboring engineering and science disciplines, with far less understanding of integrated circuit design, will also be able to increase their productivity and the functionality of the systems they design. This promise has been made repeatedly as each new higher level of computer-aided design tool is introduced and has repeatedly fallen short of fulfillment. This book presents the results of research aimed at introducing yet higher levels of design tools that will inch the integrated circuit design community closer to the fulfillment of that promise. 1. 1. SYNTHESIS OF INTEGRATED CmCUITS In the integrated circuit (Ie) design process, a behavior that meets certain specifications is conceived for a system, the behavior is used to produce a design in terms of a set of structural logic elements, and these logic elements are mapped onto physical units. The design process is impacted by a set of constraints as well as technological information (i. e. the logic elements and physical units used for the design).

The Verilog language is a hardware description language which provides a means of specifying a digital system at a wide range of levels of abstraction. The language supports the early conceptual stages of design with its behavioral level of abstraction, and the later implementation stages with its structural level of abstraction. The language provides hierarchical constructs, allowing the designer to control the complexity of a description. Verilog was originally designed in the winter of 1983/84 as a proprietary verification/simulation product. Since then, several other proprietary analysis tools have been developed around the language, including a fault simulator and a timing analyzer; the language being instrumental in providing consistency across these tools. Now, the language is openly available for any tool to read and write. This book introduces the language. It is sometimes difficult to separate the language from the simulator tool because the dynamic aspects of the language are defined by the way the simulator works. Where possible, we have stayed away from simulator-specific details and concentrated on design specification, but have included enough information to be able to have working executable models. The book takes a tutorial approach to presenting the language.

xv From the Old to the New xvii Acknowledgments xxi 1 Verilog – A Tutorial Introduction 1 Getting Started 2 A Structural Description 2 Simulating the binaryToESeg Driver 4 Creating Ports For the Module 7 Creating a Testbench For a Module 8 11 Behavioral Modeling of Combinational Circuits Procedural Models 12 Rules for Synthesizing Combinational Circuits 13 14 Procedural Modeling of Clocked Sequential Circuits Modeling Finite State Machines 15 Rules for Synthesizing Sequential Systems 18 Non-Blocking Assignment ("