利用FT8U232AM实现的USB/RS-232转换器

通用串行总线以其传输速度快、占用资源少，真正的即插即用等优点正在逐步取代传统的RS-232总线，以传统的RS-232接口为数据通信通道的外部设备可以通过USB/RS-232转换器连接在主机上，文章详细叙述了FTDI公司的USB/RS-232双向转换芯片FT8U232AM的工作原理，内部结构、引脚分布及功能，给出了一个利用FT8U232AM实现的USB/RS-232转换器的典型设计电路和驱动软件以及片外EEPROM的编程清单。     

USB接口芯片FT245BM的功能及其应用

FT245BM芯片是FTDI(Future Technology Devices Intl．Ltd)公司生产的一种USB接口芯片，支持USB协议与并行I／O协议之间的转换，文中主要介绍了FT245BM芯片的内部结构，功能，工作原理，以及基于FT245BM芯片的哽件接口设计及软件编程。     

RS232／USB转换器的设计

USB接口的外设逐步取代传统的RS232接口的外设,是当今计算机外设接口的发展趋势之一。FT8U232AM芯片可以很好地解决传统RS232接口与USB接口间协议转换的问题。文章介绍了FT8U232AM的工作原理、引脚功能以及典型电路。     

单片机开发中常用的几类USB接口芯片

依据芯片结构的不同,对单片机开发中常用的USB接口芯片做了初步的归类总结,分别介绍了EZ-USB、PDIUSBD12、FT245BM等三种不同的USB接口芯片的主要功能和特性,同时给出了它们的开发方法和接口电路.     

基于μClinux的USB芯片FT245BL驱动程序实现

μClinux是一种面向嵌入式微处理器的微型操作系统,已经在嵌入式操作系统中占有重要地位.在此介绍FTDI公司的USB芯片FT245BL的主要性能、工作原理,并将其应用在Blackfin ADSP-BF533微处理器的嵌入式开发平台上,说明在μClinux下编写与加载USB接口芯片FT245BL的驱动程序方法,实现了DSP主板的USB端口通信.     

USB接口芯片FT245AM的原理及在航空ARINC429总线测试仪中的应用

介绍了一种USB总线接口芯片FT245AM及其在航空ARINC429总线测试仪中的应用方法 ,同时介绍了FT245AM的内部结构、管脚说明以及与微处理器的接口电路 ,给出了航空ARINC429总线测试仪的总体框图、部分原理和接口逻辑的VerilogHDL源代码及仿真时序。     

总线与总线结构

0310728“VXI 总线测试软件平台”连线功能的研究与实现[刊]/杨达亮//测控技术.—2003,22(1).—53～55(E)根据 VXI 总线测试软件平台的要求和实际应用,提出了连线应有的功能,阐述了连线的实现办法,并对连线进行了测试。参100310729采用 FT8U245AM 实现 DSP 并行数据的高速 USB 传输[刊]/金月寒//国外电子元器件.—2002,(12).—25～29(C)     

串／并行USB控制器FT8U232／245的使用技巧

USB设备越来越普通,USB接口也已经成为PC的必备接口,各种USB专用控制器或者是专用芯片也随之出现。但这些产品专业性很强,现实存在的使用门坎限制了一般入门者的使用。而USB控制器FT8U232/245则最大限度地解除了这种限制。     

串／并行USB控制器FT8U232／245的使用技巧（上）

USB设备越来越普通,USB接口也已经成为PC的必备接口,各种USB专用控制器或者是专用芯片也随之出现。但这些产品专业性很强,现实存在的使用门坎限制了一般入门者的使用。而USB控制器FT8U232/245则最大限度地解除了这种限制。     

基于TUSB6020的高速数据采集系统研究

在现代生产中,数据采集作为获取信息的手段地位越来越重要,为了实现数据采集和高速传输,在概述,TI公司的TUSB6020USB2．0接口芯片功能和结果的基础上,利用TI公司的TMS320C6424数字信号处理器和TUSB6020USB2．0接口芯片组成高速数据采集系统,主要研究各个系统的特性和相互之间的连接,实现数据采集系统。实验表明,系统在DSP的控制下实现了数据的采集和高速传输。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.