高速MAC单元的设计

本文介绍一个高性能的17位乘17位加40位的乘加单元(MAC)的设计，通过将被加数作为乘法器的一个部分积参与到部分积加法阵列中来完成整个乘加运算，大幅度地提高了MAC单元的性能，在乘法器的设计中采用了改进的Booth编码技术，并且通过添加特定的部分积来避免部分积的符号位扩展和部分积产生单元中的加法操作，缩短了乘法器中关键路径的长度，最后利用HDL对设计进行描述，结合ASIC工艺库进行了综合以及资源和时延分析。     

一种支持高效加法的FPGA嵌入式DSP IP设计

提出了一种支持可变位宽高效加法的现场可编程逻辑门阵列(FPGA)嵌入式数字信号处理(DSP)单元知识产权(IP)硬核结构,相比于Altera公司的Stratix-III DSP结构,基于本文提出的优化结构可以更高效地实现加法、乘加以及累加等多种应用。利用软件对不同数据类型和位宽的输入实现数据预处理,减小了硬件资源的开销,并进一步提升了电路性能。同时在DSP结构中加入了乘法旁路器和二级符号位扩展的加法电路,在减小DSP实现面积的同时,支持超高位宽、高速的流水线型加法运算,扩展了DSP的应用范围。采用TSMC 55 nm标准CMOS工艺设计并完成了所提出的DSP IP核的电路实现,可实现包括72位可变位宽加法及36位可变位宽乘法等在内的9种运算模式。     

基于高速流水线乘加器的FIR滤波器设计

本文介绍了一种有限冲击响应(FIR)滤波器的设计,其核心部分采用12×12位流水线乘加单元(MAC)实现。乘加结构中采用非重叠多位编码产生部分积,结合进位保留加法(CSA)阵列,通过超前进位加法器(CLA)累加产生最终结果。采用VHDL对FIR滤波器进行了描述,并在FPGA中进行了综合验证。     

一种新颖的向量基-8布斯乘加器的设计

提出一种新颖的部分冗余向量基-8布斯编码乘加器,快速地处理了部分积中的正负三倍被乘数项,并以亚字并行的方式支持单指令多数据流操作,可以完成16*16的有符号乘法运算以及两个8*8的有符号乘法运算.使用了4∶2压缩器进行部分积的压缩,并使用进位控制逻辑来控制短向量间的进位.     

大整数乘法器设计

本文提出了一种有符号大整数乘法的实现算法,该算法避免了部分积的符号扩展,使部分积之间的累加比较规则,易于VLSI实现.并且文中给出了该算法的一种逻辑实现结构,这种结构减少了乘法计算过程中进位传递加法的次数,加快了乘法计算的速度.     

基于Booth算法的32×32乘法器IP核设计

在Booth算法的基础上,提出了一个适用于多媒体加速单元(Multirnedia Accelerator)的乘法器IP核设计。通过增加一位符号位,本设计支持32X32无符号和有符号乘法。通过一个32X9结合2-bit Booth算法阵列乘法器循环四次加法．完成32bit乘法。前四个时钟周期,每次处理一个9bit乘法,后两个周期分别处理低32bit和高32bit加法。我们采用2．5v,0．25μm SMIC CMOS工艺,实现乘法器的设计,其中部分积求和部分和ALU单元．Hspice仿真的最大延迟分别为0．64ns,1．51ns。     

DSP专用高速乘法器的设计

介绍了一种DSP专用高速乘法器的设计方法.该乘法器采用了最优化Booth编码算法,降低了部分乘积的数目,采用Wallace Tree最优化的演算法和快速超前进位加法器来进一步提高电路的运算速度.该乘法器在一个时钟周期内可以完成16位有符号/无符号二进制数乘法运算和复乘运算,在slow corner下最高频率可达220MHz以上.本乘法器是一DSP内核的专用乘法单元,整个设计简单高效.     

高性能SIMD乘法阵列体系结构

描述了一种新型的高性能高能效SIMD乘法阵列的结构.该乘法阵列支持同时执行1个64位乘法,4个32位乘法或16个16位有符号/无符号乘法.通过修改乘法算法实现结构,提高了乘加单元的面积复用度,在较小的面积和性能开销下实现了上述功能.并引入了"溢出补偿技术"解决了复数矩阵乘法运算的判溢出问题.通过牺牲非关键路径上短位宽乘法性能,提高关键路径上高位宽乘法性能.所述结构与文献[1]中乘法簇结构相比,64位乘法延时减少3.65%,面积降低3.92%,功耗提高5.71%.     

BCD码代数和平均值运算电路

在一般运算器设计中,将数进行算术加或者减的运算时,其数可采用补码或反码表示,这样就可全部归结为加法运算.并且可根据数值的正负,设立符号位,符号位也参加运算,就可获得正确的结果.在此情况下,加或者减的运算方式仅取决于输入两个数的符号.当符号相同时,进行加法运算;当符号相异时,则进行减法运算.只是在进行加法运算时,必须考虑和的最高位进位可能侵占符号位,从而使结果发生错误的问题.     

一种32位高速浮点乘法器设计

文章介绍一种32位浮点乘法器软IP的设计,其部分积缩减部分采用修正Booth算法,部分积加法采用4-2压缩树结构,最终carry、sum形式部分积采用进位选择加法器完成,乘法器可以进行32位浮点数或24位定点数的乘法运算。采用VerilogHDLRTL级描述,采用SMIC0.18μm工艺库进行综合,门级仿真结果表明乘法器延时小于4.05ns。     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.