基于龙芯平台的J-Link协议移植实现

介绍目前在嵌入式系统中广泛应用的仿真器J-Link和龙芯处理器,论述J-Link协议在龙芯平台上的移植实现过程,给出移植过程中的关键步骤,即J-Link的初始化、EJTAG控制数据的组织、J-Link的协议封装、数据对齐以及USB协议使用,在龙芯平台上可成功实现移植过程。实验结果表明,与现有方法相比,使用移植后的J-Link仿真器进行EJTAG在线烧写Flash,烧写的速度及系统稳定性提高明显。     

龙芯3号处理器多核虚拟化技术

MIPS 处理器是精简指令集（RISC）处理器中的一个重要代表,通常应用于嵌入式系统中.近年来,随着MIPS处理器性能的大幅度提升,其应用渐渐扩展到了高性能服务器领域.龙芯3号处理器是MIPS架构的典型代表.在目前的服务器研究领域中,多核技术是一项重要的技术指标,而虚拟化技术是另一项重要的技术指标.当前,虽然虚拟化技术得到了快速发展,但是龙芯3号处理器上的虚拟化技术却鲜有成果.基于龙芯3号处理器的多核虚拟化技术面临许多问题,虚拟多核架构结构复杂、核间通信方式难以模拟等都会为龙芯3号处理器上的多核虚拟化带来困难.分析了多核龙芯3号处理器的硬件结构以及物理多核的核间中断通信方式,在此基础上介绍了龙芯3号处理器上多核虚拟化关键技术.主要在多核处理器虚拟化总体架构设计、虚拟多核结构设计以及虚拟多核的核间通信方式等方面进行了讨论.实验的结果表明,在龙芯3号处理器上,该多核虚拟化方法具有良好的效果.     

一种面向多核处理器的通用可调试性架构

硅后调试对于当代集成电路设计变得日益重要,用于辅助硅后调试的可调式性设计(DFD)应运而生.由于多核处理器往往包含多种不同类型的部件,每个部件都有各自的调试功能需求,极大地提高了可调式性设计的复杂度.针对上述问题,提出一种面向片上多核处理器的通用可调试性架构.该架构使用简单的监测器来监测和控制处理器中用于互连的片上网络,通过专门的调试总线将各个监测器与调试总控模块连接在一起,并使用EJTAG通用调试接口与外部调试主机传递信息.与传统的可调试性架构相比,该架构无需片上RAM,硬件代价低,具有模块化的特性.此外,文中提出的架构采用了工业界通用的EJTAG调试接口,因此通用性较高,已经被应用于龙芯-3B多核处理器中.实验结果显示,该架构可以在高频高数据带宽的环境下工作.     

龙芯2号处理器功能部件设计

功能部件是处理器中进行指令运算的核心单元，它的算法及其实现直接影响到处理器的总体性能．介绍了龙芯2号处理器的功能部件，探讨了从算法到物理设计等不同层次的功能部件设计方法．龙芯2号功能部件分为两个定点ALU和两个浮点ALU实现，除实现完整的MIPS定、浮点指令集外，还实现了龙芯2号类MMX自定义多媒体指令集以及定点操作在浮点部件（FPU）中的数据通路复用．龙芯2号浮点部件遵照IEEE754和MIPS相关标准，浮点加法4拍完成，浮点乘法5拍完成，浮点除法4～17拍完成．物理设计支持0．18μm工艺下主频500MHz的标准单元实现，浮点单精度峰值性能达到2GFLOPS．双精度峰值性能达到1GFLOPS．     

龙腾九州中国“心”——千元龙芯电脑架构分析

2006年9月13日是我国龙芯计划一个重要的里程碑。“64位龙芯2号增强型处理器（简称龙芯2E．英文名为Godson-2）”通过科技部验收．该处理器最高主频达到1GHz．实测性能超过1．5GHz奔腾4处理器水平。同日．“龙芯2号增强型处理器”通过了科技成果鉴定。值得注意的是，龙芯2家族中．2E是第一款量产的处理器．同时．装备龙芯2E的龙梦电脑即将投入市场．这标志着龙芯2代处理器进入产业化进程。 龙芯2从最初型号发展到现在的2E．经历了怎样的变化？龙芯2采用MIPS架构．比起目前的主流CPU性能究竟如何？龙梦电脑能和大家熟悉的主流PC竞争吗？Windows操作系统能否支持龙芯处理器？应用程序软件能否满足大众的需求？这些都是大家关心的问题。[编者按]     

嵌入式处理器在片调试功能的设计与实现

以龙芯1号处理器为研究对象,探讨了嵌入式处理器中在片调试功能的设计实现方法.通过扩充IEEEP1149.1协议的JTAG测试访问端口（TAP）,并在处理器内部增加控制模块,实现了软件调试断点、调试中断、硬件断点以及单步执行等多种在片调试功能.调试主机只需要通过一根JTAG调试电缆就可以访问目标处理器内部寄存器等各种资源,并控制目标处理器的运行过程,实现了处理器的在片调试功能,大大地方便了软件开发与系统调试.     

MIPS公司授权中科院计算技术研究所使用MIPS架构

MIPS科技公司（MIPS Technologies,Inc）宣布,中国科学院计算技术研究所（ICT）已获得MIPS32和MIPS64架构授权,以进一步推动龙芯系列处理器的开发与商业化工作。2007年,MIPS科技的授权客户意法半导体（STMieroelectronics）选用MIPS64架构来支持jCT的龙芯处理器研发。本次则是该机构首度直接取得MIPS塞构授权。     

龙芯2号微处理器的功能验证

开发龙芯2号这样的高性能通用处理器是一项极其复杂的艰巨任务．龙芯2号处理器的设计规模和复杂度比龙芯1号增加了许多倍,如何保证设计的正确性是一个重大挑战．简单的系统级测试已经不能满足设计的需要,这就要求采用多种有效的、先进的验证方法和工具帮助设计者尽可能早的发现和改正设计错误．主要介绍了在龙芯2号处理器的设计开发过程中采用的功能验证流程和主要验证方法．模拟仿真是主要的验证手段,新的形式化验证方法也应用到了验证流程当中．     

性能大跃进

MIPS架构让龙芯处理器拥有低成本的特点，但如果以此为卖点，周边配套产品也以低成本为第一要务，龙芯产业化发展恐怕将难以顺利展开。     

周期精确ASIP仿真器生成环境的研究

周期精确仿真器是ASIP(专用指令集处理器)开发过程中的关键工具.介绍了一种由体系结构描述语言mtADL驱动的周期精确ASIP仿真器的快速生成环境.mtADL可以简洁精确地描述嵌入式领域最常见的2种微体系结构(简单流水线和Tomasulo动态调度流水线).仿真器生成器mtGEN能够根据mtADL的描述,自动生成周期精确的仿真器.介绍了mtGEN使用的自动生成算法.在实验部分,对5级流水MIPS、3级流水ARM7和动态调度MIPS这三种差异很大的处理器实现了周期精确仿真器自动生成,从而证明了方法的正确性和有效性.     

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。