用TOP-DOWN进行FPGA设计的优越性

现场可编程门阵列电路(FPGA)很快即成为低密度到中等密度逻辑电路中占优势的半导体工艺。FPGA当前已占了以前为PLD或低密度CMOS门阵列电路备用的板插槽的很大的百分比数量,并且正在成为许多设计师的ASIC设计过程的不可缺少的组成部分。     

40nm FPGA给国防电子带来的优势和挑战

引言随着Altera 40nm FPGA的推出,越来越多的军用电子设计领域开始采用可编程逻辑器件(PLD)进行设计(见图1)。这反映了军用电子的集成需求,也是芯片尺寸不断发展导致ASIC成本攀升的结果。利用FPGA来实现以往局限于ASIC设计或微处理器系统的功能,不但可以缩短设计周期,还能够简化硬件验证。     

ASIC蒸蒸日上

逻辑电路是电子产品中最具个性的部分,是电子产品设计中最具有特色的地方。在IC中一直占有重要的地位。过去逻辑线路是用通用的逻辑IC联接起来的。但是,自从出现了专用集成电路(ASIC),逻辑电路在越来越多的情況下,就以ASIC的型式出现。传统意义上的通用逻辑电路只占总逻辑电路(包括ASIC)销售额的10％左右。而ASIC的绝大部分功能是起逻辑电路的作用。所以,近来的统计资料都将通用逻辑电路和ASIC统计在一起。逻辑电路占整个IC销售额的19％左右。     

ASIC蒸蒸日上

逻辑电路是电子产品中最具个性的部分,是电子产品设计中最具有特色的地方。在IC中一直占有重要的地位。过去逻辑线路是用通用的逻辑IC联接起来的。但是,自从出现了专用集成电路(ASIC),逻辑电路在越来越多的情况下,就以ASIC的型式出现。传统意义上的通用逻辑电路只占总逻辑电路(包括ASIC)销     

手把手教你学CPLD／FPGA设计（十一）上

组合逻辑电路的设计实验 数字逻辑电路系统按功能的不同,可以分为组合逻辑电路和时序逻辑电路两大类。组合逻辑电路在任意时刻产生的输出只取决于该时刻的输入,而与电路过去的输入无关。常见的组合逻辑电路有数据选择器、编码器、译码器、加法器等。     

可编程逻辑器件产业发展趋势

可编程逻辑器(PLD)是70年代发展起来的新型逻辑器件,可以完全由用户配置以完成某种特定的逻辑功能。经过80年代的发展,PLD行业初步形成,而进入90年代以后,可编程逻辑器件成为半导体领域中发展最快的产品之一。可编程器件是在ASIC设计的基础上发展起来的,在ASIC设计方法中,通常采用全定制和半定制电路设计方法,但设计完成后如果不能满足要求,还要重新设计再进行验证。这样不但会导致设计开发周期变长,产品上市时间难以保证,而且会大大增加产品的开发费用。     

时序逻辑电路ASIC化PLA模型设计法（一）

专用可编程集成电路（ASICApplicationSpecificIntegratedCircuit）是速度快、集成度高、用户可编程的逻辑器件。近几年，在数字系统和计算机外围接口电路设计中ASIC得到了广泛的应用。本文给出的用PLA模型设计时序逻辑电路的方法不同于传统的时序电路设计方法，更适用于ASIC实现时序逻辑电路。文中给出了经过仿真和验证、功能正确的设计实例电路。     

从ASIC到PLD:半导体技术市场趋势展望

根据Dataquest的统计数据,PLD是半导体行业中增长最快的细分市场,复合年度增长率(CAGR)达19.5%。这一数字是ASIC市场预计9%复合年度增长率的两倍多。过去,可编程芯片在半导体行业中一直是很重要的外围器件,由于其灵活性而被广泛用于ASIC仿真、胶合逻辑,或者作为适应标准变化的一种解决方案。今天,在与ASIC和ASSP的市场份额竞争中,PLD取得了很大进步。目前,该技术正逐渐成为主要设计技术,而且业界也在普遍向可编程芯片转移。作为重要的ASIC替代解决方案,PLD现在已成为大势所趋。促进这种发展的主要因素是FPGA技术的重大进展…     

用PLD设计不同长度的序列信号发生器

序列信号发生器一般用触发器加组合逻辑电路的方法设计，电路设计和实现较为复杂，借助典型移存型序列信号发生器设计方法，通过定义PLD器件内部的逻辑和输入输出引出端，可简化设计，提高电路的性能，文中给出了几个设计例子。     

一种基于时序逻辑电路的延时开关设计

时序逻辑电路设计是《数字电子技术》课程中一个难度大、综合性高的部分,它综合了组合逻辑电路和时序逻辑电路的内容。在进行状态机设计时,随着输入逻辑变量的增加,状态数目将呈指数倍急剧增加,这会使整个设计变得复杂且容易出错。以一个延时开关控制器的设计为例,提出了一种状态机输入变量简化的方法,降低了设计过程的复杂程度。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks