UART微控制器设计方法及其FPGA实现

为满足FPGA与PC之间的通信需求,提出了一种FPGA的通用异步收发器设计实现方法。在Xilinx ISE 11开发平台上采用Verilog HDL硬件描述语言及其自带的IP CORE,实现了UART精确波特率时钟模块、UART发送模块和UART接收模块。并在ISE环境下进行综合建模仿真,给出各模块的仿真时序图以及综合生成的RTL图。实验通过Xilinx公司的XC2VP30 FPGA开发板对程序进行下载运行调试,与PC进行实时通信,结果表明,UART控制器工作稳定可靠,较好地实现了数据串行通信,达到预期设计要求。     

基于FPGA的多串口模块的设计和实现

UART（通用异步接收发送设备）是一种广泛应用于短距离、低速通信的串行传输接口。由于常用的UART芯片比较复杂且移植性差。文中提出了一种采用FPGA可编程门阵列器件实现8个UART的模块化设计方法。该方法首先依据系统组成来设计UART接口模块和MCU接口模块，设计中将8个UART接口和MCU接口先集成到FPGA上；其次用微处理器（MCU）对FPGA内每个UART进行控制，并通过FPGA和MCU实现多串口动态扩展（扩展到八个串口）的全双工通信。该通信方式完全遵守RS232协议，具有较强的通用性和推广价值。     

UART通信的FPGA实现设计

阐述了UART异步串行通信原理，介绍了实现UART异步串行通信的硬件接口电路及各部分硬件模块，介绍了用硬件描述语言Verilog来开发UART通信接口电路的FPGA实现。本设计使用Xilinx的FPGA器件，将UART的核心功能嵌入到FPGA内部，不但实现了电路的异步通讯的主要功能，而且使电路更加紧凑、稳定、可靠。     

基于FPGA的UART设计

UART是一种广泛应用于短距离、低速、低成本通信的串行传输接口。由于常用UART芯片比较复杂且移植性差,提出一种采用可编程器件FPGA实现UART的方法,实现了对UART的模块化设计。首先简要介绍UART的基本特点,然后依据其系统组成设计顶层模块,再采用有限状态机设计接收器模块和发送器模块,所有功能的实现全部采用VHDL进行描述,并用Modelsim软件对所有模块仿真实现。最后将UART的核心功能集成到FPGA上,使整体设计紧凑,小巧,实现的UART功能稳定、可靠。     

基于FPGA的光端机UART接口设计与实现

通用异步收发器（UART）是一种短距离串行传输接口,在光通信和控制系统中得到了广泛的应用。现场可编程门阵列（FPGA）是一种半定制的集成电路,结合计算机软件技术（EDA.技术）可以快速、方便地构建数字系统。提出了一种基于FPGA的光端机UART的设计方法,实现了对UART的模块化设计。首先简要介绍了UART的基本特点,然后采用有限状态机（FSM）设计接收器模块和发送器模块,所有功能的实现全部采用VHDL进行描述。最后给出仿真结果,验证了整个设计的正确性和可靠性。     

基于FPGA的RS232异步串行口IP核设计

为增加系统稳定性.减小电路板面积.提出一种基于FPGA的异步串行口IP核设计.该设计使用VHDL硬件描述语言对接收和发送模块在Xilinx ISE环境下设计与仿真.最后在FPGA上嵌入UART IP核实现电路的异步串行通信功能.该IP核具有模块化、兼容性和可配置性.可根据需要实现功能的升级、扩充和裁减.     

基于FPGA的通用异步收发器设计

采用Verilog HDL语言作为硬件功能的描述,运用模块化设计方法分别设计了通用异步收发器（UART）的发送模块、接收模块和波特率发生器,并结合现场可编程门阵列（FPGA）的特点,实现了一个可移植的UART模块。该设计不仅实现了串行异步通信的主要功能,而且电路简单,工作稳定、可靠,可以将其灵活地嵌入到各个通信系统中。     

基于FPGA/CPLD的通用异步通信接口UART的设计

UART（通用异步接收发送设备）是一种短距离串行传输接口。在数字通信和控制系统中得到广泛应用。FPGA／CPLD是大规模集成电路技术发展的产物．是一种半定制的集成电路。结夸计算机软件技术（EDA技术）可以快速、方便地构建数字系统。本文介绍一种采用可编程逻辑器件FPGA／CPLD实现UART的方法，将UART的核心功能集成到FPGA／CPLD上，本设计包含UART的发送模块、接收模块和波特率发生器，所有功能的实现全部采用VHDL件描述语言来进行描述。设计、综合、仿真在QUARTUSII软件开发环境下实现。     

基于FPGA实现CRC校验功能的通用异步串口通信

UART作为RS-232协议的控制接口得到了广泛的应用,为实现准确的数据串口通信,在分析CRC生成算法的基础上,提出了一种简单、实用的UART设计与实现方案。该方案在串口通信中采用CRC-5校验,基于FPGA采用Verilog语言实现CRC-5校验模块,仿真结果与理论分析一致,达到了预期设计的目标。提高了通信的速度、可靠性和效率。     

FPGA实现UART和MCU一体化设计

现代数字电子系统设计正在朝着新的方向发展．即利用FPGA技术进行系统设计。介绍了一种利用FPGA来实现通用串行异步收发器（UART）和控制通信的MCU的数字系统,底层设计模块采用VHDL硬件描述语言实现,并进行了仿真验证。该设计方法和理念为以后的计算机系统以及其他的数字电子系统提供了一个新的思路,应用此技术可以使系统设计更加紧凑、可靠。     

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.