一种适用于通信系统的异步加-选择-比较器

介绍了一种适用于Viterbi解码器的异步ACS(加法器-比较器-选择器)的设计.它采用异步握手信号取代了同步电路中的整体时钟.给出了一种异步实现结构的异步加法单元、异步比较单元和异步选择单元电路.采用全定制设计方法设计了一个异步4-bit ACS,并通过0.6μm CMOS工艺进行投片验证.经过测试,芯片在工作电压5V,工作频率20MHz时的功耗为75.5mW.由于采用异步控制,芯片在"睡眠"状态待机时不消耗动态功耗.芯片的平均响应时间为19.18ns,仅为最差响应时间23.37ns的82%.通过与相同工艺下的同步4-bit ACS在功耗和性能方面仿真结果的比较,可见异步ACS较同步ACS具有优势.     

异步集成电路标准单元的设计与实现

设计异步集成电路时,常用的异步标准单元的分类、电路设计方法和电路结构．详细介绍了C单元和异步数据通路的设计与实现,提出了一种异步实现结构的异步加法单元、异步比较单元和异步选择单元电路．利用设计的异步标准单元构成了一个适用于Viterbi解码器的异步ACS(加法器一比较器一选择器),并通过0．6μmCMOS工艺进行投片验证．当芯片工作电压为5V,工作频率为20MHz时的功耗为75．5mW．芯片的平均响应时问为19．18DS,仅为最差响应时间23．37ns的82％．从而验证了异步标准单元的正确性和异步电路在性能方面较同步电路存在的优势．     

一种新型异步ACS的CMOS VLSI设计

介绍一种新型异步 ACS(加法器 -比较器 -选择器 )的设计。一种异步实现结构的异步比较器 ,并通过异步加法单元、比较单元和选择单元的异步互连 ,构成了异步 ACS。在异步 ACS的性能分析时采用了一种基于多延迟模型的新方法 ,建立了异步加法器和比较器的多延迟模型 ,通过逻辑仿真 ,得到异步 ACS的平均响应时间为 3 .66ns,最长响应时间为 8.1 ns。由此可见 ,异步 ACS在性能方面较同步 ACS存在优势。     

低功耗异步LDPC解码器运算通路设计

本文设计了异步LDPC解码器运算通路,利用异步电路减少信号到达时间不一致引起的毛刺和时钟引起的功耗.利用输入数据的统计特性设计了运算通路中的主要运算单元,减少了冗余运算.本文还实现了同步运算通路和基于门控时钟的运算通路作为比较.三种设计采用相近的架构,在0.18μm CMOS工艺下实现相同的功能.仿真结果表明,提出的异步设计功耗最小,相比于同步设计和基于门控时钟设计,分别节省了42.0%和32.6%的功耗.虽然性能稍逊于同步设计,但优于门控时钟设计.其中,同步设计的延时是1.09ns,基于门控时钟的设计延时是1.61ns,而异步设计则是1.20ns.     

一种新型低功耗异步比较器的设计方法

本文利用输入数据的统计特性,设计了两种低功耗异步比较器——异步行波比较器和提前终止异步比较器.异步行波比较器从第一个不相等的数位开始停止运算,但要把结果传到最低位,消耗部分功耗.提前终止异步比较器通过修改真值表,基于新的比较单元电路和终止判断电路,在第一个不相等的数位停止运算并立即输出比较结果,节省不必要的功耗.新设计的异步比较器和用于对比的同步比较器(BCL比较器和门控时钟比较器)均用SMIC0.18μm工艺实现.仿真结果表明,提前终止异步比较器功耗最低,与同步BCL比较器和门控时钟比较器相比,在随机数据和来自LDPC解码器的数据下,分别节省了87.1%、84.5%和37.5%、28.6%的功耗.     

采用异步实现的快速傅里叶变换处理器

介绍一种采用异步实现结构的快速傅里叶变换处理器,该处理器的控制采用本地握手信号取代传统的系统时钟。给出了处理器中异步加法器的电路结构,设计了一个采用Booth译码Wallace tree结构的异步乘法器。通过对一个8点的异步快速傅里叶变换处理器进行电路仿真,得到该处理器完成一次变换的平均响应时间为31.15 ns,仅为最差响应时间42.85 ns的72.7%。可见,采用异步方式的快速傅里叶变换处理器在性能方面较同步处理器存在优势。     

新型异步树型仲裁器设计

树型仲裁器是异步电路中常用的电路,它的性能和鲁棒性对整个系统有很大的影响.针对以往树型仲裁器在设计和应用方面存在的问题,设计并实现了一种新型异步树型仲裁器,提高了异步树型仲裁器的鲁棒性.该仲裁器采用了插入差分电路和隔断两级逻辑电路的方法,避免了毛刺的出现.通过重新设计C单元,避免了现有树型仲裁器的死锁问题.在CSMC 0.5μmCMOS工艺下,该仲裁器的最短数据传输时间为4.37 ns,电路平均功耗为50.815 nW.     

一种异步快速傅立叶变换处理器设计

针对一种异步实现结构的异步快速傅立叶变换处理器,给出了处理器中异步加法器的电路和异步乘法器的结构．该异步快速傅立叶变换处理器采用本地的握手信号代替了传统的整体时钟．通过对一个8点的异步快速傅立叶变换处理器电路仿真,得到该处理器的平均响应时间为31．15ns,仅为最差响应时间42．85ns的72．7％．由此可见,异步快速傅立叶变换处理器在性能方面较同步处理器存在优势。     

低功耗跨导-电容滤波器及其调谐电路的设计

设计了一种以Nauta跨导为单元结构的5阶切比雪夫跨导-电容带通滤波器及其调谐电路.该电路应用于低中频结构的北斗卫星导航接收机射频前端.滤波器的中心频率为4.092MHz,带宽设计为±2.046 MHz.该滤波器采用锁相环结构的片上自动频率调谐电路,用TSMC0.13 μm RF CMOS工艺实现,芯片面积仅为0.24 mm2,可以在低电压下工作,电路总功耗仅为1.68 mW.     

DES算法的四相捆绑数据协议异步电路实现

DES算法是典型的对称加密算法,广泛应用于商业化领域中,如各种智能卡等。对称算法的实现基本上都是基于同步电路设计。本文采用基于四相捆绑数据协议的异步电路方法实现了DES算法。将DES算法的同步电路设计和异步设计放到非接触智能卡芯片中,通过对芯片进行测试,对两种设计结果进行了全面的比较,从而表明用异步电路实现的对称算法在功耗和运算速度方面具有显著的优势。     

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.