100G以太网CGMII接口的电路设计

随着云计算技术的发展,数据中心的规模和性能必须有很大提升,智能终端通信带宽也必须相应提高。100G以太网相对千兆以太网,数据位宽更大,时钟频率更高。因此,MII接口的设计和实现都面临新的挑战。本文主要研究100G以太网介质无关接口(CGMII)的设计,完成根据协议规定在全双工模式下的MAC帧数据类型的转化,以及对链路故障的处理。     

片间高速图像传输系统的设计与实现

针对图像采集与处理系统研发中的现场可编程门阵列(FPGA)之间的高速图像数据传输问题,设计了一种全双工、高吞吐率、高稳定性和高抗干扰能力的高速图像数据传输方案。设计的片间高速图像传输系统提供了通用的图像传输接口,可兼容不同的数据位宽和用户时钟频率。高速图像传输模块分为协议层和物理层。协议层包括跨时钟域电路和CXP图像传输协议编译码电路,完成跨时钟域和图像数据流编译码处理;物理层基于Aurora 8B/10B core,完成数据流的串并转换以及多通道绑定等处理,并采用GTH收发器实现高速串行数据的收发。仿真测试表明,图像数据传输正确,图像数据流同步时钟最高可达250 MHz,传输位宽达128 bit,最高吞吐率可达32 Gbit/s,平均吞吐率为20 Gbit/s,并且还有很大的提升潜力。该高速图像传输系统能够实现高吞吐率、高抗干扰、低错误率的图像数据传输,有助于各种不同视觉测量系统和图像处理系统的开发,具有广泛的应用价值。     

支持数据缓存的LVDS-以太网转接板设计

低电压差分信号（LVDS）具有抗干扰能力强、传输距离远等优点，已被广泛应用于嵌入式系统各模块间的数据传输。同时，在实际应用中，模块与主机间的连通接口采用千兆以太网网口来提高数据交互速度。一种LVDS-以太网转接板设计可以用于模块与主机间的信息交互，满足LVDS信号到以太网传输信号的转换需求。转接板采用可扩展处理平台作为核心处理芯片，利用片内高速总线加快数据传输，实现高效、轻量化设计。通过增加数据缓存功能电路及对应逻辑，有效提高了处理器的工作效率，避免数据丢失。经过模块的系统测试验证，LVDS-以太网转接板能够实现LVDS信号到网口的转接需求，并支持数据缓存功能。     

一种基于DDR高速图像缓存的实现

提出了基于 DDR 存储器的高速 FIFO 图像缓存方案,降低了用户接口的设计难度,实现了高速缓存的容量扩展,并成功应用于工程项目。本文设计中使用16bit 数据位宽的 DDR 器件,创新地实现了行猝发的操作模式,极大地提高了数据吞吐量。在工作时钟为100MHz 的条件下实现了平均缓存速度高达360MB/s,接近理论峰值数据吞吐量400MB/s。     

万兆以太网MAC层控制器的FPGA设计与实现

根据IEEE802.3-2005和IEEE802.3ae标准,在Xilinx公司的Virtex6系列XC6VHX255T器件上设计实现了万兆以太网MAC层控制器。与千兆以太网相比,万兆以太网使用更宽的数据位宽和更高的时钟频率,这使得其MAC层控制器的设计和实现都面临新的挑战。在解决了数据并行处理、不定长字节CRC编码/校验及与千兆以太网兼容等问题的基础上,设计实现了万兆以太网MAC层控制器。经布局布线后仿真验证,说明该设计可满足万兆以太网实际应用的要求。     

基于MPC860T的MII实现

MII是一个逻辑信号接口 ,是 10 Mb/ s AUI的 10 0 Mb/ s等价物 .它使得在 MAC层和协调子层 (RS)之下可以支持不同的介质类型 .本文介绍了 10 0 Mbps以太网的 MII接口及其基于 MPC86 0 T的实现     

基于FPGA的RGMII与MII协议转换器的实现

为提高嵌入式系统在网络应用的灵活性,降低接口实现和维护成本,通过分析研究MII和RGMII以及以太网IEEE802.3推荐标准,结合FPGA强大的数据处理能力和可重配置能力,设计实现了RGMII与MII接口协议转换器。仿真实验结果表明,该接口转换功能实现正常,工作稳定,有效解决了传统嵌入式系统接口灵活性差和维护成本高的问题,并为其他信号接口系统的设计实现提供了有益的参考。     

朗讯科技贝尔实验室在十万兆光纤以太网领域再续辉煌

日前在美国加州Anaheim召开的光电光纤通讯研讨会圾展览会（OFC）上，朗讯科技公司贝尔实验室宣布在全球首次成功实现电子复用107Gbit／s数据光纤传输；在业内致力于在城域网中实现100Gbil/s以太网数据联网的进程中，该成果是又一重要里程碑。     

基于FPGA的SRIO多通道控制系统设计与实现

在板间互联及芯片互联方式上，SRIO具有更高的带宽及实时性。使用MSG（消息）接口的HELLO格式，发送端采用多接口设计方法，内部采用Round-Robin处理机制，实现了多通道接口在同时发送数据时共用一个SRIO接口的竞争处理；同时封装为多通道的输入输出的方式，支持接口数量、时钟域的任意扩展。经过测试验证，该系统最大可实现64个不同时钟下通道的数据收发，单通道下包和包之间延时最低可到4μs，在SRIO传输应用方向上，具有较好的应用价值。     

基于AXI总线的可配置LVDS控制器设计与验证

针对不同应用场景下LVDS通信协议体现在数据位宽、帧格式和存储方式的选择差异性和数据收发灵活性,提出一种基于AXI总线的可配置LVDS控制器设计与验证方案.为了实现对LVDS控制器的精确控制,增加基于APB接口的可配置寄存器模块,在SoC系统上由软件控制数据传输,有效提高了数据收发的灵活性;为了提高传输效率并广泛适应场...     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。