Asynchronous Circuits

With asynchronous circuit design becoming a powerful tool in thedevelopment of new digital systems, circuit designers are expectedto have asynchronous design skills and be able to leverage them toreduce power consumption and increase system speed. This book walksreaders through all of the different methodologies of asynchronouscircuit design, emphasizing practical techniques and real-worldapplications instead of theoretical simulation. The only guide ofits kind, it also features an ftp site complete with supportmaterials. Market: Electrical Engineers, Computer Scientists, DeviceDesigners, and Developers in industry. An Instructor Support FTP site is available from the Wileyeditorial department.

Principles of Asynchronous Circuit Design - A Systems Perspective addresses the need for an introductory text on asynchronous circuit design. Part I is an 8-chapter tutorial which addresses the most important issues for the beginner, including how to think about asynchronous systems. Part II is a 4-chapter introduction to Balsa, a freely-available synthesis system for asynchronous circuits which will enable the reader to get hands-on experience of designing high-level asynchronous systems. Part III offers a number of examples of state-of-the-art asynchronous systems to illustrate what can be built using asynchronous techniques. The examples range from a complete commercial smart card chip to complex microprocessors. The objective in writing this book has been to enable industrial designers with a background in conventional (clocked) design to be able to understand asynchronous design sufficiently to assess what it has to offer and whether it might be advantageous in their next design task.

In recent years, there has been a great surge of interest in asynchronous circuits, largely through the development of new asynchronous design methodologies. This book provides a comprehensive theory of asynchronous circuits, including modelling, analysis, simulation, specification, verification, and an introduction to their design.

This book is intended for designers with experience in traditional (clocked) circuit design, seeking information about asynchronous circuit design, in order to determine if it would be advantageous to adopt asynchronous methodologies in their next design project. The author introduces a generic approach for implementing a deterministic completion detection scheme for asynchronous bundled data circuits that incorporates a data-dependent computational process, taking advantage of the average-case delay. The author validates the architecture using a barrel shifter, as shifting is the basic operation required by all the processors. The generic architecture proposed in this book for a deterministic completion detection scheme for bundled data circuits will facilitate researchers in considering the asynchronous design style for developing digital circuits.

Designing Asynchronous Circuits using NULL Convention Logic (NCL) begins with an introduction to asynchronous (clockless) logic in general, and then focuses on delay-insensitive asynchronous logic design using the NCL paradigm. The book details design of input-complete and observable dual-rail and quad-rail combinational circuits, and then discusses implementation of sequential circuits, which require datapath feedback. Next, throughput optimization techniques are presented, including pipelining, embedding registration, early completion, and NULL cycle reduction. Subsequently, low-power design techniques, such as wavefront steering and Multi-Threshold CMOS (MTCMOS) for NCL, are discussed. The book culminates with a comprehensive design example of an optimized Greatest Common Divisor circuit. Readers should have prior knowledge of basic logic design concepts, such as Boolean algebra and Karnaugh maps. After studying this book, readers should have a good understanding of the differences between asynchronous and synchronous circuits, and should be able to design arbitrary NCL circuits, optimized for area, throughput, and power. Table of Contents: Introduction to Asynchronous Logic / Overview of NULL Convention Logic (NCL) / Combinational NCL Circuit Design / Sequential NCL Circuit Design / NCL Throughput Optimization / Low-Power NCL Design / Comprehensive NCL Design Example

As the costs of power and timing become increasingly difficult to manage in traditional synchronous systems, designers are being forced to look at asynchronous alternatives. Based on reworked and expanded papers from the VII Banff Higher Order Workshop, this volume examines asynchronous methods which have been used in large circuit design, ranging from initial formal specification to more standard finite state machine based control models. Written by leading practitioners in the area, the papers cover many aspects of current practice including practical design, silicon compilation, and applications of formal specification. It also includes a state-of-the-art survey of asynchronous hardware design. The resulting volume will be invaluable to anyone interested in designing correct asynchronous circuits which exhibit high performance or low power operation.

This book introduces a wide range of existing and potential applications for asynchronous circuits, each accompanied with the corresponding circuit design theory, sample circuit implementations, results, and analysis.

Since the second half of the 1980s asynchronous circuits have been the subject of a great deal of research following a period of relative oblivion. The lack of interest in asynchronous techniques was motivated by the progressive shift towards synchronous design techniques that had much more structure and were much easier to verify and synthesize. System design requirements made it impossible to eliminate totally the use of asynchronous circuits. Given the objective difficulty encountered by designers, the asynchronous components of electronic systems such as interfaces became a serious bottleneck in the design process. The use of new models and some theoretical breakthroughs made it possible to develop asynchronous design techniques that were reliable and effective. This book describes a variety of mathematical models and of algorithms that form the backbone and the body of a new design methodology for asyn chronous design. The book is intended for asynchronous hardware designers, for computer-aided tool experts, and for digital designers interested in ex ploring the possibility of designing asynchronous circuits. It requires a solid mathematical background in discrete event systems and algorithms. While the book has not been written as a textbook, nevertheless it could be used as a reference book in an advanced course in logic synthesis or asynchronous design.