USB接口高速数据传输的实现

USB接口具有即插即用、安装方便、高带宽、易扩展、传输速度快等优点,尽管USB2.0规范中最高传输速度已经达到了60MB/s,但是很多USB2.0设备在实际工作时的数据传输速度却与此相差甚远,设计了一个以FPGA为主控制器、以CY7C68013为接口芯片的数据采集系统;当接口芯片CY7C68013工作在同步的Slave FIFO模式下时,在数据的传输控制上设计了块传输同步控制信号,保证数据传输的正确性和稳定性,系统所能达到稳定的最高传输速度为31.8MB/s。     

FPGA和USB2.0双工接口设计

为了实现FPGA与USB2.0之间稳定快速的数据传输,该设计利用USB2.0接口芯片CY7C68013的Slave FIFO模式,采用时分复用的方法设计了一种双向数据接口。在FPGA端,持续把从USB OUT FIFO读出的数据回写到USB IN FIFO,以实现系统的自环测试。该设计已被应用到超宽带(UWB)无线系统中,结果表明本接口工作稳定,数据传输准确,平均速率12Mb/s。     

基于NIOS II处理器的USB双向数据传输系统

介绍了一种双向数据传输系统设计方案和实现方法,采用USB2.0接口芯片CY7C68013A与FPGA相结合构建硬件系统,FPGA内嵌NIOS Ⅱ软核处理器负责数据处理;系统通过USB接口向上传输数据到上位机,结合基于VC++开发的数据传输控制软件平台,发送控制命令及数据到硬件系统端,从而实现USB接口的双向数据传输功能;详细描述了系统的硬件电路设计和软件实现过程,实验证明该系统具有高速、便携、通用性强的特点,系统数据最高传输速度达到33MB/s,且工作稳定可靠。     

高速大容量记录仪的USB3.0高速读数接口设计

针对当前USB 2.0已不能满足对高速大容量数据记录仪快速读数的要求,设计了一种基于USB 3.0的高速读数接口。系统以存储阵列构建的某高速大容量机载雷达数据记录仪为背景,USB 3.0采用Slave FIFO接口模式,以记录仪的FPGA为外部主控制器,在FPGA内部构建一个高速FIFO实现对存储数据的缓存与传输,最后通过USB 3.0接口高速传输至计算机。重点介绍了USB 3.0读数接口硬件及其固件程序和FPGA控制程序的设计,并采用GPIF Designer II及Quartus II软件进行仿真与验证。实验结果表明,该USB 3.0接口速率可达120 MB/s,满足记录仪高速读取的要求。     

基于FPGA的USB3.0通信架构设计与实现

针对USB设备与主机通信存在的带宽瓶颈问题,设计一款基于USB3.0协议的高速通信架构,为嵌入式设备与PC之间的USB数据高速通信提供一种可选方案。本设计采用Cypress的EZ-USB FX3芯片作为USB的外设控制器,以FPGA作为整个硬件系统的主控芯片,通过对FPGA硬件系统进行设计,对设备固件进行设计与调优,该架构支持USB 2.0/3.0接口自适应,能够实现主机、国产嵌入式CPU、SRAM之间的两两可变帧长通信,硬件传输速度达到360 MB/s,数据连续传输速度达到148 MB/s。     

基于USB 3.0的高速数据传输接口设计

针对在高速数据采集过程中,需要向计算机实时传输大量数据,通过对各种传输方式的研究分析,提出了采用USB 3.0传输方式进行数据传输,设计了基于USB 3.0的高速数据传输接口,接口实现的关键技术之一是稳定数据传输的速度。通过对各种USB 3.0芯片分析,采用了FTDI公司生产的FT601芯片,根据相应的数据手册,完成对FT601芯片的外围电路,采用可编程逻辑门阵列(FPGA)作为USB 3.0传输控制器。使用Verilog语言对FPGA内部进行编程,实现使用先进先出(FIFO)方式对数据进行缓存,控制FT601芯片完成与上位机之间的数据交换,并进行测试。测试结果表明,接口能在进行相应配置后,以平均350MB/s的速率传输数据,保证了数据传输速度的稳定性和数据的完整性。     

争分夺秒还是多此一举U盘/SD卡提速大作战

打破USB2.0接口常规传输速度 并不是所有的台式机和笔记本都配备有USB3.0接口,尤其是购机较早的台式机用户和购买低价入门级笔记本的用户,USB3.0接口离他们还有些距离.不过连续大幅度降价让USB3.0接口U盘迅速得以普及,这使得不少用户拿着USB3.0存储设备,却无法享受高速数据传输的快感. 其实USB2.0接口的理论数据传输速度可达480Mbps (60MB/s),不过由于受到各种系统协议(Bulk-Only Transport(BOT)协议)和编码方式(NRZI编码方式)的限制,USB2.0接口实际传输速度通常被限制在30MB/s左右,仅为理论最高传输速度的一半.我们无法改变USB传输底层NRZI编码方式,但可以通过修改Bulk-Only Transport(BOT)协议区块大小,增加USB带宽利用率,提升USB2.0接口常规传输速度.     

基于FPGA和USB3.0的通用数据传输系统设计

现场可编程门阵列(FPGA)的高度灵活性和强大的数据处理能力,使其在越来越多的领域得到应用。USB 3.0也是目前主流的数据传输协议之一,具有速度快、功耗低等优点。将USB 3.0接口应用到FPGA上,能够有效地解决FPGA与上位机之间的数据传输问题,大大提高生产效率。文章利用USB 3.0的控制器芯片CYUSB3014实现了FPGA与上位机之间的高达390 MB/s的数据传输系统。     

基于FPGA的对击锤力能参数测量仪设计

为实现在锻造生产中对击锤打击能量、打击力等力能参数的测量,设计了一种基于FPGA与USB2.O的四通道、高速同步数据采集系统;硬件采用两个压电式加速度传感器和两个位移传感器,FPGA选用Ahera公司的EP2C5Q240I8,通过对打击过程中524 ms内的加速度和位移数据的采集,计算出力能参数,并通过USB2.0将数据实时上传到PC机进行处理;重点介绍系统硬件电路设计、USB2.0控制逻辑和FPGA内部状态机模块设计;系统采样频率达到1 MHz,数据传输速率达到30 MB/s,现场测试证明,该系统能够在强冲击、大振动环境下稳定可靠工作,为锻造质量控制提供了可靠的科学依据。     

基于同步Slave FIFO技术的高速USB数传系统设计

给出一种基于"USB2.0Slave接口芯片+FPGA"架构的高速USB数传系统设计方案。系统以CY7C68013A为USB协议桥、FPGA为逻辑控制单元,优化设计有限状态机实现同步Slave FIFO接口协议,构建了USB数据高速传输通道,保证了数据传输、处理过程中的可靠性、实时性和高效性;优化了芯片固件加载方式,实现了系统在线自动升级加载功能。经实测,系统的数据传输处理能力平均可达320Mb/s,接近USB2.0协议规定的极限速率,固件可在1.2s内完成自动加载,使系统具备了快速升级能力。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.