On-chip micronetworks, designed with a layered methodology, will meet the distinctive challenges of providing functionally correct, reliable operation of interacting system-on-chip components. A system on chip (SoC) can provide an integrated solution to challenging design problems in the telecommunications, multimedia, and consumer electronics domains. Much of the progress in these fields hinges on the designers' ability to conceive complex electronic engines under strong time-to-market pressure. Success will require using appropriate design and process technologies, as well as interconnecting existing components reliably in a plug-and-play fashion. Focusing on using probabilistic metrics such as average values or variance to quantify design objectives such as performance and power will lead to a major change in SoC design methodologies. Overall, these designs will be based on both deterministic and stochastic models. Creating complex SoCs requires a modular, component-based approach to both hardware and software design. Despite numerous challenges, the authors believe that developers will solve the problems of designing SoC networks. At the same time, they believe that a layered micronetwork design methodology will likely be the only path to mastering the complexity of future SoC designs.

Networks on chips: a new SoC paradigm

This ebook is the first authorized digital version of Kernighan and Ritchie's 1988 classic, The C Programming Language (2nd Ed.). One of the best-selling programming books published in the last fifty years, "K&R" has been called everything from the "bible" to "a landmark in computer science" and it has influenced generations of programmers. Available now for all leading ebook platforms, this concise and beautifully written text is a "must-have" reference for every serious programmers digital library.

As modestly described by the authors in the Preface to the First Edition, this "is not an introductory programming manual; it assumes some familiarity with basic programming concepts like variables, assignment statements, loops, and functions. Nonetheless, a novice programmer should be able to read along and pick up the language, although access to a more knowledgeable colleague will help."

The C programming language

The scaling of microchip technologies has enabled large scale systems-on-chip (SoC). Network-on-chip (NoC) research addresses global communication in SoC, involving (i) a move from computation-centric to communication-centric design and (ii) the implementation of scalable communication structures. This survey presents a perspective on existing NoC research. We define the following abstractions: system, network adapter, network, and link to explain and structure the fundamental concepts. First, research relating to the actual network design is reviewed. Then system level design and modeling are discussed. We also evaluate performance analysis techniques. The research shows that NoC constitutes a unification of current trends of intrachip communication rather than an explicit new alternative.

/pdf/a-survey-of-research-and-practices-of-network-on-chip-2rc0mlsrfq.pdf

A survey of research and practices of Network-on-chip

This paper presents an architectural study of a scalable system-level interconnection template. We explain why the shared bus, which is today's dominant template, will not meet the performance requirements of tomorrow's systems. We present an alternative interconnection in the form of switching networks. This technology originates in parallel computing, but is also well suited for heterogeneous communication between embedded processors and addresses many of the deep submicron integration issues. We discuss the necessity and the ways to provide high-level services on top of the bare network packet protocol, such as dataflow and address-space communication services. Eventually we present our first results on the cost/performance assessment of an integrated switching network.

/pdf/a-generic-architecture-for-on-chip-packet-switched-4el4cut58z.pdf

A generic architecture for on-chip packet-switched interconnections

Multiprocessor system-on-chip (MP-SoC) platforms are emerging as an important trend for SoC design. Power and wire design constraints are forcing the adoption of new design methodologies for system-on-chip (SoC), namely, those that incorporate modularity and explicit parallelism. To enable these MP-SoC platforms, researchers have recently pursued scaleable communication-centric interconnect fabrics, such as networks-on-chip (NoC), which possess many features that are particularly attractive for these. These communication-centric interconnect fabrics are characterized by different trade-offs with regard to latency, throughput, energy dissipation, and silicon area requirements. In this paper, we develop a consistent and meaningful evaluation methodology to compare the performance and characteristics of a variety of NoC architectures. We also explore design trade-offs that characterize the NoC approach and obtain comparative results for a number of common NoC topologies. To the best of our knowledge, this is the first effort in characterizing different NoC architectures with respect to their performance and design trade-offs. To further illustrate our evaluation methodology, we map a typical multiprocessing platform to different NoC interconnect architectures and show how the system performance is affected by these design trade-offs.

/pdf/performance-evaluation-and-design-trade-offs-for-network-on-2r2qk1xk70.pdf

Performance evaluation and design trade-offs for network-on-chip interconnect architectures

This paper presents the SPIN micro-network that is a generic, scalable interconnect architecture for system on chip. The SPIN architecture relies on packet switching and point-to-point bi-directional links between the routers implementing the micro-network. SPIN gives the system designer the simple view of a single shared address space and provides a variable number of VCI compliant communication interfaces for both initiators (masters) and targets (slaves). Performance comparisons between a classical PI-bus based interconnect and the SPIN micro-network are analyzed.

/pdf/spin-a-scalable-packet-switched-on-chip-micro-network-3v2e1bc4c2.pdf

SPIN: A Scalable, Packet Switched, On-Chip Micro-Network

The distribution of a synchronous clock in system-on-chip (SoC) has become a problem, because of wire length and process variation. Novel approaches such as the globally asynchronous, locally synchronous try to solve this issue by partitioning the SoC into isolated synchronous islands. This paper describes the bisynchronous FIFO used on the DSPIN network-on-chip capable to interface systems working with different clock signals (frequency and/or phase). Its interfaces are synchronous and its architecture is scalable and synthesizable in synchronous standard cells. The metastability situations and its latency are analyzed. Its throughput, maximum frequency, and area are evaluated in function of the FIFO depth.

Bi-Synchronous FIFO for Synchronous Circuit Communication Well Suited for Network-on-Chip in GALS Architectures

The paper presents the DSPIN micro-network, that is an evolution of the SPIN architecture DSPIN is a scalable packet switching micro-network dedicated to GALS (Globally Asynchronous, Locally Synchronous) clustered, multi-processors, systems on chip The DSPIN architecture has a very small foot-print and provides to the system designer both guaranteed latency, and guaranteed throughput services for real-time applications

A Low Cost Network-on-Chip with Guaranteed Service Well Suited to the GALS Approach

High frequency clock rate is a key issue in today's VLSI. To improve performance on-chip, clock multipliers are used. But it is a difficult task to design such circuits while maintaining low cost. This paper presents a circuit fabricated to test a new method of clock frequency multiplication. This new approach uses a digital CMOS process in order to implement a fully integrated digital delay locked loop. This multiplier does not require external components. Moreover, as it is primarily intended for ASIC design, it is generated by a parameterized generator written in C which relies on a portable digital standard cell library for automatic place and route. The design based on the delay locked loop allows the clock waveform to reach its operating point faster than conventional methods. Special techniques enable high multiplication factors (between 4 and 20) without compromising the timing accuracy. With a clock multiplier of 20, in 1 /spl mu/m CMOS process and a 5 V supply voltage, a 170 MHz clock signal has been obtained from a 8.5 MHz external clock with a measured jitter lower than 300 ps.

Alain Greiner

Papers

A generic architecture for on-chip packet-switched interconnections

SPIN: A Scalable, Packet Switched, On-Chip Micro-Network

Bi-Synchronous FIFO for Synchronous Circuit Communication Well Suited for Network-on-Chip in GALS Architectures

A Low Cost Network-on-Chip with Guaranteed Service Well Suited to the GALS Approach

A portable clock multiplier generator using digital CMOS standard cells