Driven by steep increase in the complexity of computations, processing speed requirements and the volume of data handled in various signal processing applications, modern signal processing research and development is undergoing a major revolution. On the other hand, the availability of low cost, high density, fast-speed VLSI devices has timely opened a new avenue for implementing these increasingly sophisticated algorithms and systems. Therefore, the future trend of VLSI signal processing research will require very close interactions between different disciplines in VLSI, computer engineering, and signal processing. This paper addresses three fundamental issues: (1) impact of VLSI on signal processing methods, (2) impact of VLSI on array processors for signal processing, (3) integrated design of signal processing systems. The purpose is to provide a cross-disciplinary understanding of the modern signal processing techniques, parallel array processors, and VLSI technology potentials and constraints. (Author).

Even elementary school students of today know that electronics can do fan tastic things. Electronic calculators make arithmetic easy. An electronic box connected to your TV set provides a wonderful array of games. Electron ic boxes can translate languages! Electronics has even changed watches from a pair of hands to a set of digits. Integrated circuit (IC) chips which use transistors to store information in binary form and perform bin ary arithmetic make all of this possible. In just a short twenty years the field of integrated circuits has progressed from a few transistors per chip to thousands of transistors per chip. Since the early 1960's, the field has progressed from chips containing several transistors performing simple functions such as OR and AND functions to chips presently available which contain thousands of transistors performing a wide range of memory, control and arithmetic functions. The number of special journal issues, conferences, workshops, seminars, etc. related to the field of IC's is large. l~hile no single volume could adequately summarize the field, this volume attempts to provide a summary of some of the important issues and factors for Very Large Scale Integra tion (VLSI) from the perspective of several authors deeply involved in the field. In the field of VLSI, composed of many facets and disciplines, the de mand for engineers, physicists and chemists trained in IC skills exceeds supply.

Many modern applications, such as signal processing and real-time simulation, require large amounts of computation. This poses a dilemma: General-purpose computers are too costly for real-time applications, and special-purpose hardware is not flexible enough for research and development work. Traditionally, Peripheral Array Processor (PAP) provide a cost-effective compromise that combines the best of both worlds: large amounts of computation performed at a very high rate, at a reasonable cost, and without loss of generality or programmability. Therefore, throughout this note PAPs are used as the baseline for the discussion of signal processing engines. With the rapid advance of VLSI technology new alternatives have emerged, such as the so-called signal processor on a chip and numerous special purpose processing devices. An interesting question is, are the new VLSI devices about to do to the conventional signal processors what microprocessors and PAPs did to mainframes? (Author).

When comparing conventional computing architectures to the architectures of biological neural systems, we find several striking differences. Conventional computers use a low number of high performance computing elements that are programmed with algorithms to perform tasks in a time sequenced way; they are very successful in administrative applications, in scientific simulations, and in certain signal processing applications. However, the biological systems still significantly outperform conventional computers in perception tasks, sensory data processing and motory control. Biological systems use a completely dif ferent computing paradigm: a massive network of simple processors that are (adaptively) interconnected and operate in parallel. Exactly this massively parallel processing seems the key aspect to their success. On the other hand the development of VLSI technologies provide us with technological means to implement very complicated systems on a silicon die. Especially analog VLSI circuits in standard digital technologies open the way for the implement at ion of massively parallel analog signal processing systems for sensory signal processing applications and for perception tasks. In chapter 1 the motivations behind the emergence of the analog VLSI of massively parallel systems is discussed in detail together with the capabilities and !imitations of VLSI technologies and the required research and developments. Analog parallel signal processing drives for the development of very com pact, high speed and low power circuits. An important technologicallimitation in the reduction of the size of circuits and the improvement of the speed and power consumption performance is the device inaccuracies or device mismatch.

This book is the first in a set of forthcoming books focussed on state-of-the-art development in the VLSI Signal Processing area. It is a response to the tremendous research activities taking place in that field. These activities have been driven by two factors: the dramatic increase in demand for high speed signal processing, especially in consumer elec tronics, and the evolving microelectronic technologies. The available technology has always been one of the main factors in determining al gorithms, architectures, and design strategies to be followed. With every new technology, signal processing systems go through many changes in concepts, design methods, and implementation. The goal of this book is to introduce the reader to the main features of VLSI Signal Processing and the ongoing developments in this area. The focus of this book is on: • Current developments in Digital Signal Processing (DSP) pro cessors and architectures - several examples and case studies of existing DSP chips are discussed in Chapter 1. • Features and requirements of image and video signal processing architectures - both applications specific integrated circuits (ASICs) and programmable image processors are studied in Chapter 2. • New market areas for signal processing - especially in consumer electronics such as multimedia, teleconferencing, and movie on demand. • Impact of arithmetic circuitry on the performance of DSP pro cessors - several topics are discussed in Chapter 3 such as: number representation, arithmetic algorithms and circuits, and implementa tion.