/pdf/convex-analysisnoer-san-nojin-zhan-nituite-5dl2rbmoyr.pdf

Convex Analysisの二,三の進展について

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.

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

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

The continuous advances in semiconductor technology enable the integration of increasing numbers of IP blocks in a single SoC. Interconnect infrastructures, such as buses, switches, and networks on chips (NoCs), combine the IPs into a working SoC. Moreover, the industry expects platform-based SoC design to evolve to communication-centric design, with NoCs as a central enabling technology. In this article, we introduce the AEthereal NoC. The tenet of the AEthereal NoC is that guaranteed services (GSs) - such as uncorrupted, lossless, ordered data delivery; guaranteed throughput; and bounded latency - are essential for the efficient construction of robust SoCs. To exploit the NoC capacity unused by the GS traffic, we provide best-effort services.

/pdf/aethereal-network-on-chip-concepts-architectures-and-1tugx9w8o1.pdf

AEthereal network on chip: concepts, architectures, and implementations

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

Networks on chip (NoCs) are a scalable interconnect solution for multiprocessor systems on chip. We propose a generic reconfigurable online event-based NoC monitoring service, based on hardware probes attached to NoC components, offering run-time observability of NoC behavior and supporting system-level debugging. We present a probe architecture, its programming model, traffic management strategies, and a cost analysis. We prove feasibility via a prototype implementation for the AEthereal NoC. Two MPEG NoC examples show that the monitoring service area, without advanced optimizations, is 17--24p of the NoC area. Two realistic monitoring examples show that monitoring traffic is several orders of magnitude lower than the 2GB/s/link raw bandwidth.

/pdf/an-event-based-monitoring-service-for-networks-on-chip-4dlxqw2rdk.pdf

An event-based monitoring service for networks on chip

System-on-chip (soc) design gets increasingly complex, as a growing number of applications are integrated in modern systems. Some of these applications have real-time requirements, such as a minimum throughput or a maximum latency. To reduce cost, system resources are shared between applications, making their timing behavior inter-dependent. Real-time requirements must hence e verified for all possible combinations of concurrently executing applications, which is not feasible with commonly used simulation-based techniques. This chapter addresses this problem using two complexity-reducing concepts: composability and predictability. Applications in a composable system are completely isolated and cannot affect each other's behaviors, enabling them to be independently verified. Predictable systems, on the other hand, provide lower bounds on performance, allowing applications to be verified using formal performance analysis. Five techniques to achieve composability and/or predictability in soc resources are presented and we explain their implementation for processors, interconnect, and memories in our platform.

/pdf/composability-and-predictability-for-independent-application-1eg2tcsw4q.pdf

Composability and Predictability for Independent Application Development,Verification, and Execution

Networks-on-chip (NoC) are a scalable interconnect solution to multiprocessor systems on chip (MPSoC). NoCs transport data in packets which are fragments of transactions, such as read and write actions of IPs. For debug purposes, reconstructing transactions at run-time is essential. Run-time analysis of the NoC behavior at transaction level makes the complete MPSoC easier to understand. We present a NoC analyzer able to monitor NoC transactions at run-time. The proposed hardware transaction monitor is able to reconstruct on-chip, at run-time, NoC transactions from bit-level intercepted router link communication. Four NoC analyzer modes are detailed raising the abstraction level gradually from physical raw to logical connection-based, transaction-based and abstract transaction event-based. Each mode is analyzed for area and bandwidth in an experimental setup based on several AEligthereal NoC designs. A transaction monitor has an area cost of 0.026 mm2 in a 0.13 mum CMOS technology, and for several MPEG/audio case studies, the entire monitoring system adds an average of 5% to the NoC area. We show the versatility of our NoC analyzer by run-time monitoring user connections and the Configuration Master IP in the NoC.

/pdf/transaction-monitoring-in-networks-on-chip-the-on-chip-run-18ruwhgj7a.pdf

Transaction Monitoring in Networks on Chip: The On-Chip Run-Time Perspective

As the complexity of Systems-on-Chip (SoC) is growing, meeting real-time requirements is becoming increasingly difficult. Predictability for computation, memory and communication components is needed to build real-time SoC. We focus on a predictable communication infrastructure called the AEthereal Network-on-Chip (NoC). The AEthereal NoC is a scalable communication infrastructure based on routers and network interfaces (NI). It provides two services: guaranteed throughput and latency (GT), and best effort (BE). Using the GT service, one can derive guaranteed bounds on latency and throughput. To achieve guaranteed throughput, buffers in NI must be dimensioned to hide round-trip latency and rate difference between computation and communication IPs (Intellectual Property). With the BE service, throughput and latency bounds cannot be derived with guarantees. In this chapter, we describe an analytical method to compute latency, throughput and buffering requirements for the AEthereal NoC. We show the usefulness of the method by applying it on an MPEG-2 (Moving Picture Experts Group) codec example.

/pdf/building-predictable-systems-on-chip-an-analysis-of-5ccleoy8za.pdf

Building Predictable Systems on Chip: An Analysis of Guaranteed Communication in the Aethereal Network on Chip

Problems in a new System on Chip (SOC) consisting of hardware and embedded software often only show up when a silicon prototype of the chip is placed in its intended target environment and the application is executed. Traditionally, the debugging of embedded systems is difficult and time consuming because of the intrinsic lack of internal system observability and controlability in the target environment. Design for Debug (DfD) is the act of adding debug support to the design of a chip, in the realization that not every SOC is correct first time. DfD provides debug engineers with increased observability and controlability of the internal operation of an embedded system. In this paper, we present a monitoring infrastructure for multi-processor SOCs with a Network on Chip (NOC), and explain its application to performance analysis and debug. We describe how our monitors aid in the performance analysis and debug of the interactions of the embedded processors. We present a generic template for bus and router monitors, and show how they are instantiated at design time in our NOC design flow. We conclude this paper with details of their hardware cost.

Kees Goossens

Papers

An event-based monitoring service for networks on chip

Composability and Predictability for Independent Application Development,Verification, and Execution

Transaction Monitoring in Networks on Chip: The On-Chip Run-Time Perspective

Building Predictable Systems on Chip: An Analysis of Guaranteed Communication in the Aethereal Network on Chip

A Network-on-Chip monitoring infrastructure for communication-centric debug of embedded multi-processor SoCs