On Chip Networks

This book targets engineers and researchers familiar with basic computer architecture concepts who are interested in learning about on-chip networks. This work is designed to be a short synthesis of the most critical concepts in on-chip network design. It is a resource for both understanding on-chip network basics and for providing an overview of state of the-art research in on-chip networks. We believe that an overview that teaches both fundamental concepts and highlights state-of-the-art designs will be of great value to both graduate students and industry engineers. While not an exhaustive text, we hope to illuminate fundamental concepts for the reader as well as identify trends and gaps in on-chip network research. With the rapid advances in this field, we felt it was timely to update and review the state of the art in this second edition. We introduce two new chapters at the end of the book. We have updated the latest research of the past years throughout the book and also expanded our coverage of fundamental concepts to include several research ideas that have now made their way into products and, in our opinion, should be textbook concepts that all on-chip network practitioners should know. For example, these fundamental concepts include message passing, multicast routing, and bubble flow control schemes.

With the ability to integrate a large number of cores on a single chip, research into on-chip networks to facilitate communication becomes increasingly important. On-chip networks seek to provide a scalable and high-bandwidth communication substrate for multi-core and many-core architectures. High bandwidth and low latency within the on-chip network must be achieved while fitting within tight area and power budgets. In this lecture, we examine various fundamental aspects of on-chip network design and provide the reader with an overview of the current state-of-the-art research in this field. Table of Contents: Introduction / Interface with System Architecture / Topology / Routing / Flow Control / Router Microarchitecture / Conclusions

As the number of processor cores and IP blocks integrated on a single chip is steadily growing, a systematic approach to design the communication infrastructure becomes necessary. Different variants of packed switched on-chip networks have been proposed by several groups during the past two years. This book summarizes the state of the art of these efforts and discusses the major issues from the physical integration to architecture to operating systems and application interfaces. It also provides a guideline and vision about the direction this field is moving to. Moreover, the book outlines the consequences of adopting design platforms based on packet switched network. The consequences may in fact be far reaching because many of the topics of distributed systems, distributed real-time systems, fault tolerant systems, parallel computer architecture, parallel programming as well as traditional system-on-chip issues will appear relevant but within the constraints of a single chip VLSI implementation.

Addresses the Challenges Associated with System-on-Chip Integration Network-on-Chip: The Next Generation of System-on-Chip Integration examines the current issues restricting chip-on-chip communication efficiency, and explores Network-on-chip (NoC), a promising alternative that equips designers with the capability to produce a scalable, reusable, and high-performance communication backbone by allowing for the integration of a large number of cores on a single system-on-chip (SoC). This book provides a basic overview of topics associated with NoC-based design: communication infrastructure design, communication methodology, evaluation framework, and mapping of applications onto NoC. It details the design and evaluation of different proposed NoC structures, low-power techniques, signal integrity and reliability issues, application mapping, testing, and future trends. Utilizing examples of chips that have been implemented in industry and academia, this text presents the full architectural design of components verified through implementation in industrial CAD tools. It describes NoC research and developments, incorporates theoretical proofs strengthening the analysis procedures, and includes algorithms used in NoC design and synthesis. In addition, it considers other upcoming NoC issues, such as low-power NoC design, signal integrity issues, NoC testing, reconfiguration, synthesis, and 3-D NoC design. This text comprises 12 chapters and covers: The evolution of NoC from SoC—its research and developmental challenges NoC protocols, elaborating flow control, available network topologies, routing mechanisms, fault tolerance, quality-of-service support, and the design of network interfaces The router design strategies followed in NoCs The evaluation mechanism of NoC architectures The application mapping strategies followed in NoCs Low-power design techniques specifically followed in NoCs The signal integrity and reliability issues of NoC The details of NoC testing strategies reported so far The problem of synthesizing application-specific NoCs Reconfigurable NoC design issues Direction of future research and development in the field of NoC Network-on-Chip: The Next Generation of System-on-Chip Integration covers the basic topics, technology, and future trends relevant to NoC-based design, and can be used by engineers, students, and researchers and other industry professionals interested in computer architecture, embedded systems, and parallel/distributed systems.

The design of today's semiconductor chips for various applications, such as telecommunications, poses various challenges due to the complexity of these systems. These highly complex systems-on-chips demand new approaches to connect and manage the communication between on-chip processing and storage components and networks on chips (NoCs) provide a powerful solution. This book is the first to provide a unified overview of NoC technology. It includes in-depth analysis of all the on-chip communication challenges, from physical wiring implementation up to software architecture, and a complete classification of their various Network-on-Chip approaches and solutions. * Leading-edge research from world-renowned experts in academia and industry with state-of-the-art technology implementations/trends * An integrated presentation not currently available in any other book * A thorough introduction to current design methodologies and chips designed with NoCs

[2]. The Cell Processor from Sony, Toshiba and IBM (STI) [3], and the Sun UltraSPARC T1 (formerly codenamed Niagara) [4] signal the growing popularity of such systems. Furthermore, Intel’s very recently announced 80-core TeraFLOP chip [5] exemplifies the irreversible march toward many-core systems with tens or even hundreds of processing elements. 1.2 The Dawn of the Communication-Centric Revolution The multi-core thrust has ushered the gradual displacement of the computati- centric design model by a more communication-centric approach [6]. The large, sophisticated monolithic modules are giving way to several smaller, simpler p- cessing elements working in tandem. This trend has led to a surge in the popularity of multi-core systems, which typically manifest themselves in two distinct incarnations: heterogeneous Multi-Processor Systems-on-Chip (MPSoC) and homogeneous Chip Multi-Processors (CMP). The SoC philosophy revolves around the technique of Platform-Based Design (PBD) [7], which advocates the reuse of Intellectual Property (IP) cores in flexible design templates that can be customized accordingly to satisfy the demands of particular implementations. The appeal of such a modular approach lies in the substantially reduced Time-To- Market (TTM) incubation period, which is a direct outcome of lower circuit complexity and reduced design effort. The whole system can now be viewed as a diverse collection of pre-existing IP components integrated on a single die.

Networks-on-Chip: From Implementations to Programming Paradigms provides a thorough and bottom-up exploration of the whole NoC design space in a coherent and uniform fashion, from low-level router, buffer and topology implementations, to routing and flow control schemes, to co-optimizations of NoC and high-level programming paradigms. This textbook is intended for an advanced course on computer architecture, suitable for graduate students or senior undergrads who want to specialize in the area of computer architecture and Networks-on-Chip. It is also intended for practitioners in the industry in the area of microprocessor design, especially the many-core processor design with a network-on-chip. Graduates can learn many practical and theoretical lessons from this course, and also can be motivated to delve further into the ideas and designs proposed in this book. Industrial engineers can refer to this book to make practical tradeoffs as well. Graduates and engineers who focus on off-chip network design can also refer to this book to achieve deadlock-free routing algorithm designs. Provides thorough and insightful exploration of NoC design space. Description from low-level logic implementations to co-optimizations of high-level program paradigms and NoCs. The coherent and uniform format offers readers a clear, quick and efficient exploration of NoC design space Covers many novel and exciting research ideas, which encourage researchers to further delve into these topics. Presents both engineering and theoretical contributions. The detailed description of the router, buffer and topology implementations, comparisons and analysis are of high engineering value.

This book provides a comprehensive survey of recent progress in the design and implementation of Networks-on-Chip. It addresses a wide spectrum of on-chip communication problems, ranging from physical, network, to application layers. Specific topics that are explored in detail include packet routing, resource arbitration, error control/correction, application mapping, and communication scheduling. Additionally, a novel bi-directional communication channel NoC (BiNoC) architecture is described, with detailed explanation. Written for practicing engineers in need of practical knowledge about the design and implementation of networks-on-chip; Includes tutorial-like details to introduce readers to a diverse range of NoC designs, as well as in-depth analysis for designers with NoC experience to explore advanced issues; Describes a variety of on-chip communication architectures, including a novel bi-directional communication channel NoC. From the Foreword: Overall this book shows important advances over the state of the art that will affect future system design as well as R&D in tools and methods for NoC design. It represents an important reference point for both designers and electronic design automation researchers and developers. --Giovanni De Micheli