循环冗余校验码并行算法的FPGA实现

通过对CRC(循环冗余校验)码本身特点的观察与分析,推导出并行算法的逻辑关系,并利用VHDL语言设计一个CRC(24,8)码编码器,在QuartusⅡ平台下给出了该编码器的仿真结果,仿真结果表明与串行算法相比并行算法提高了校验速率。     

循环冗佘校验码并行算法的FPGA实现

通过对CRC（循环冗余校验）码本身特点的观察与分析,推导出并行算法的逻辑关系,并利用VHDL语言设计一个CRC（24,8）码编码器,在QuartusⅡ平台下给出了该编码器的仿真结果,仿真结果表明与串行算法相比并行算法提高了校验速率。     

ROHC协议中CRC计算的硬件实现

ROHC协议是IETF专门针对无线链路的特点而设计的包头压缩规范,CRC码的产生、校验和更新是其中重要的组成部分.在分析CRC快速准确并行算法的基础上,针对ROHC中具体应用要求,给出其CRC计算的硬件并行实现设计方案,并用Verilog HDL语言编写代码进行了仿真和验证,结果表明此方案具有很好的实用性和灵活性.     

针对任意位的CRC并行化方法及编解码器的实现

介绍了一种基于查表法的针对任意位数据的任意位CRC并行计算的原理及算法，克服了现有的两类CRC并行算法延时大、毛刺多或仅适于2^n位数据的2^n位CRC校验的缺点。该方法使并行CRC校验的传输数据位数与CRC码位数之间的选择更灵活，并且在加速比、功耗和面积等方面具有优势。     

GPON中高速并行RS编码器的实现

RS码是一种纠错能力很强的线性分组码,可大幅提高通信系统性能。针对吉比特无源光网络,设计并实现了32位并行RS（255,239）编码器。编写VerilogHDL代码,利用QuartusII软件验证功能的正确性。结果表明该编码器运行速度快,占用资源少,满足GPON系统高速数据传输的要求。     

JPEG2000中高速Tier1编码器的VLSI设计

提出并实现了一种用于JPEG2000编码芯片中高速Tier1编码器的并行流水结构。该编码器采用了双位平面并行编码、通道扫描的流水控制、状态变量实时产生电路以及列内并行上下文生成等技术,实现了一种0状态存储器的多并行流水位平面编码器;并行同步流水的多记号输入算术编码器以及不定算术编码周期下的多输入同步读取电路,使算术编码速度平均为1.3上下文编码记号对/时钟;对算术编码产生的压缩码流存储呈高效的宏流水线结构。该编码器在100MHz工作时钟下,最高编码速度为85M小波系数/s。用SMIC0.25μm工艺库综合时,门电路为6.3万门,片上存储器为26kb(码块大小32×32),关键路径为5.2ns。     

USB3．0中的CRC校验原理及实现

循环冗余码（CRC）是USB协议中重要的错误检测措施。在此分析了USB3．0数据包的基本格式以及USB3．0协议中CRC校验的特点,针对USB3．0数据高速传输的要求,设计实现并行发送端CRC产生和接收端CRC校验电路,功能仿真结果证明了其有效性。     

高速并行BCH(2184,2040)编码器的VLSI优化设计

介绍一种实现并行BCH编码器的设计方法,并基于TSMC 0.18μm CMOS工艺设计了用于高速光通信FEC(前向纠错)级联码的并行BCH(2184,2040)编码器.采用树型结构减少逻辑层次,选择适当的共享子表达式减少逻辑门的数量,并用限制共享子表达式的最大个数和负载均衡方法降低BCH长码的扇出瓶颈影响,减少关键路径的延时,提高工作速度.优化设计的并行BCH(2184,2040)编码器可以实现2.5Gb/s的数据吞吐率.     

高速并行LDPC编码的FPGA实现

LDPC码具有优异的误码性能,并被很多协议采用,其中CCSDS规范就采用了LDPC码。符合CCSDS规范的LDPC码编码器的设计目的是满足卫星实际应用的需求,降低卫星信道传输的误码率。实现了8位并行LDPC码编码,并优化了矩阵信息的存储设计。在XC2V3000 FPGA实测中,8位并行编码吞吐量达到800 Mbps。     

基于SATAⅡ协议的CRC32并行算法的研究

在介绍CRC校验原理和传统CRC32串行比特算法的基础上,由串行比特型算法推导出一种CRC32并行算法。并结合SATAⅡ协议的要求,完成了SATAⅡ主控制器设计中CRC生成与校验模块的设计。最后通过在ISE平台上编写Verilog硬件描述语言,对SATA协议中帧结构数据进行仿真,验证该CRC32并行算法能够满足SATA接口实时处理的要求。     

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.