Asynchronous Circuit Design for VLSI Signal Processing is a collection of research papers on recent advances in the area of specification, design and analysis of asynchronous circuits and systems. This interest in designing digital computing systems without a global clock is prompted by the ever growing difficulty in adopting global synchronization as the only efficient means to system timing. Asynchronous circuits and systems have long held interest for circuit designers and researchers alike because of the inherent challenge involved in designing these circuits, as well as developing design techniques for them. The frontier research in this area can be traced back to Huffman's publications The Synthesis of Sequential Switching Circuits' in 1954 followed by Unger's book, Asynchronous Sequential Switching Circuits' in 1969 where a theoretical foundation for handling logic hazards was established. In the last few years a growing number of researchers have joined force in unveiling the mystery of designing correct asynchronous circuits, and better yet, have produced several alternatives in automatic synthesis and verification of such circuits. This collection of research papers represents a balanced view of current research efforts in the design, synthesis and verification of asynchronous systems.

Synchronization is one of the important issues in digital system design. While other approaches have always been intriguing, up until now synchro nous operation using a common clock has been the dominant design philo sophy. However, we have reached the point, with advances in technology, where other options should be given serious consideration. This is because the clock periods are getting much smaller in relation to the interconnect propagation delays, even within a single chip and certainly at the board and backplane level. To a large extent, this problem can be overcome with care ful clock distribution in synchronous design, and tools for computer-aided design of clock distribution. However, this places global constraints on the design, making it necessary, for example, to redesign the clock distribution each time any part of the system is changed. In this book, some alternative approaches to synchronization in digital sys tem design are described and developed. We owe these techniques to a long history of effort in both digital system design and in digital communica tions, the latter field being relevant because large propagation delays have always been a dominant consideration in design. While synchronous design is discussed and contrasted to the other techniques in Chapter 6, the dom inant theme of this book is alternative approaches.

Asynchronous Circuit Design for VLSI Signal Processing is a collection of research papers on recent advances in the area of specification, design and analysis of asynchronous circuits and systems. This interest in designing digital computing systems without a global clock is prompted by the ever growing difficulty in adopting global synchronization as the only efficient means to system timing. Asynchronous circuits and systems have long held interest for circuit designers and researchers alike because of the inherent challenge involved in designing these circuits, as well as developing design techniques for them. The frontier research in this area can be traced back to Huffman's publications `The Synthesis of Sequential Switching Circuits' in 1954 followed by Unger's book, `Asynchronous Sequential Switching Circuits' in 1969 where a theoretical foundation for handling logic hazards was established. In the last few years a growing number of researchers have joined force in unveiling the mystery of designing correct asynchronous circuits, and better yet, have produced several alternatives in automatic synthesis and verification of such circuits. This collection of research papers represents a balanced view of current research efforts in the design, synthesis and verification of asynchronous systems.

Campy/o/meler pylori was described for the first time in 1983. Up to now more than 100 papers have been published dealing with its microbiological properties and its clinical implications. The lime has come to survey the field, to evaluate the hith erto accumulated information, and 10 discuss the questions thai should be answered in the ruture. It was for these purposes that the First International Symposium on Campy/abaeter pylori was held. bringing together specialists from a variety of discipl ines, including basic scientists as well as clinicians. This book is based on papers given at the symposium. We are very grateful 10 Rohm-Pharma for undertaking to sponsor this meeting, and to Mrs. C. 1. Klein and her starr for the impeccable organisation which permillcd us to work in such a pleasant environment, In the interest of rapidity of publication, we have reduced the amount of editing to a minimum and have not, in any sense, "re fereed" the discussions, which were written by the contributors at the time of the question-and-answer session. They were also veiled by their authors at the proof stage, and we have done our best to retain their original spontaneous flavour. We hope, in this way. 10 have produced a satisfactory record of the events and an up-Io-dale overview of research on Campylobacrer pylori."