JTAG技术的发展和应用综述

JTAG作为测试标准已为芯片设计与制造厂商接受和应用.文章概述了JTAG技术在测试领域的典型应用.同时,随着深亚微米工艺的采用,以及千兆时钟时代的来临和SOC的发展,JTAG已出现很多新的应用和实现方法.着重探讨了JTAG的发展,及其在信号完整性测试、嵌入式调试、差分信号测试等技术中的应用.     

JTAG界面——一个供IC用的标准测试界面

针对大规模集成电路中利用传统的探针测试方法浪费时间,不能检测IC引脚内部信号的原因.本文系统地论述了JTAG如何来解决上述问题的的方法和手段,以及JTAG的指令.     

JTAG界面——一个供IC用的标准测试界面

针对大规模集成电路中利用传统的探针测试方法浪费时间,不能检测IC引脚内部信号的原因.本文系统地论述了JTAG如何来解决上述问题的的方法和手段,以及JTAG的指令.     

基于JTAG的矢量生成型边界扫描架构设计与实现

在结合IEEE1149.1标准的基础上,利用半跳变(Half Transition,HT)模型的基本思想,提出新的HTF模型新的矢量施加方式,在此基础上构建了实现基于JTAG的矢量生成型边界扫描架构.该架构的设计思路为:在兼容1149.1的基础上,通过自定义SI测试指令,实现JTAG对信号完整性测试的支持,拓展了边界扫描的应用范围.     

一种适合于SOC系统的JTAG扩展化可测性设计

随着集成电路系统复杂性的提高及基于 IP核的 SOC系统的出现 ,电路测试的难度不断增大 ,对电路可测性设计提出了更高的要求。文中在研究了现有各种可测性设计方法优劣后提出了扩展化的 JTAG可测性设计电路 ,它在稍增加电路复杂度的情况下融合各测试方法 ,并提出了利用这种测试电路的 IC系统测试方案。它克服了测试基于 IP核的 SOC系统的一些难点。     

JTAG接口下载线的制作

图1JTAG是IEEE委员会的联合测试小组制定的测试标准。它使用户可以测试器件的逻辑和PCB板上的各器件的内部连接。现在,很多器件都兼容JTAG标准。我们可以利用JTAG标准做到在系统可编程,这就给我们的开发工作带来很大的便利。例如:我们可以用JTAG标准在嵌入式系统的开发中对FLASH做到在系统可编程。一些并口的驱动软件可以从网上下载,本文介绍JTAG接口下载线的制作。1.电路原理图 很多人不知道下载线的构成,总以为比较复杂。其实,下载线的原理并不复杂,主要就是一片74LS244和几个电阻组成。主要完成的功能就是总线驱动和接口…     

SOC中的MBIST设计

随着超大规模集成电路的发展,设计的集成度越来越高,基于IP的SOC设计正在成为IC设计的主流.为了确保SOC的功能正确,可测性设计(Design for Test,简称DFT)显得尤为关键.DFT设计包括扫描设计、JTAG设计和BIST设计.另外,当前SOC芯片中集成了大量的存储器,为了确保存储器没有故障,基于存储器的...     

边界扫描测试的原理及应用设计

文章介绍了边界扫描测试的原理 ,分析了联合测试行动组JTAG控制器的逻辑状态 ,并给出了JTAG测试具体应用的VHDL原代码和逻辑仿真波形。利用JTAG接口可以方便地进行复杂IC芯片连接的故障定位 ,灵活控制IC芯片进入特定的功能模式等。     

JTAG界面——一个供IC用的标准测试界面

针对大规模集成电路中利用传统的探针测试方法浪费时问,不能检测IC引脚内部信号的原因。本文系统地论述了JTAG如何来解决上述问题的的方法和手段,以及JTAG的指令。     

基于JTAG标准的电流模A/D转换器可测试性设计

边界扫描技术是一种重要的可测试性设计（DFT）技术，该技术不仅可以测试芯片或PCB之间的管脚连接是否存在故障，还可以测试芯片的逻辑功能。JTAG标准是该技术的相关协议。以JTAG标准为基础，结合一款新型电流模A／D转换器的测试需求，提出了一种基于JTAG标准的扫描测试结构，完成对电流模A／D转换器的参数测试。     

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.