This Application Note covers the basics of how to use Verilog as applied to ComplexProgrammable Logic Devices. Various combinational logic Circuit examples, such asmultiplexers, decoders, encoders, comparators and adders are provided. Synchronous logicCircuit examples, such as counters and state machines are also provided.
上传时间： 2013-11-11
上传用户：y13567890
Finite state machines are widely used in digital Circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized Circuit. Sometimes, however, the optimization is not acceptable. For example, if the Circuit powers up in an invalid state, or the Circuit is in an extreme working environment and a glitch sends it into an undesired state, the Circuit may never get back to its normal operating condition.
标签： Creating Machines Mentor State
上传时间： 2013-11-02
上传用户：xauthu
为了在CDMA系统中更好地应用QDPSK数字调制方式，在分析四相相对移相（QDPSK)信号调制解调原理的基础上，设计了一种QDPSK调制解调电路，它包括串并转换、差分编码、四相载波产生和选相、相干解调、差分译码和并串转换电路。在MAX+PLUSⅡ软件平台上，进行了编译和波形仿真。综合后下载到复杂可编程逻辑器件EPM7128SLC84-15中，测试结果表明，调制电路能正确选相，解调电路输出数据与QDPSK调制输入数据完全一致，达到了预期的设计要求。 Abstract: In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation Circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion Circuit, differential encoding Circuit, four-phase carrier wave produced and phase chosen Circuit, coherent demodulation Circuit, difference decoding Circuit and parallel/serial conversion Circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation Circuit can exactly choose the phase，and the output data of the demodulator Circuit is the same as the input data of the QDPSK modulate. The Circuit achieves the prospective requirement of the design.
上传时间： 2013-10-28
上传用户：jyycc
【摘要】本文结合作者多年的印制板设计经验，着重印制板的电气性能，从印制板稳定性、可靠性方面，来讨论多层印制板设计的基本要求。【关键词】印制电路板；表面贴装器件；高密度互连；通孔【Key words】Printed Circuit Board；Surface Mounting Device；High Density Interface；Via一．概述印制板（PCB－Printed Circuit Board）也叫印制电路板、印刷电路板。多层印制板，就是指两层以上的印制板，它是由几层绝缘基板上的连接导线和装配焊接电子元件用的焊盘组成，既具有导通各层线路，又具有相互间绝缘的作用。随着SMT（表面安装技术）的不断发展，以及新一代SMD（表面安装器件）的不断推出，如QFP、QFN、CSP、BGA（特别是MBGA），使电子产品更加智能化、小型化，因而推动了PCB工业技术的重大改革和进步。自1991年IBM公司首先成功开发出高密度多层板（SLC）以来，各国各大集团也相继开发出各种各样的高密度互连（HDI）微孔板。这些加工技术的迅猛发展，促使了PCB的设计已逐渐向多层、高密度布线的方向发展。多层印制板以其设计灵活、稳定可靠的电气性能和优越的经济性能，现已广泛应用于电子产品的生产制造中。下面，作者以多年设计印制板的经验，着重印制板的电气性能，结合工艺要求，从印制板稳定性、可靠性方面，来谈谈多层制板设计的基本要领。
上传时间： 2013-10-08
上传用户：zhishenglu
本文利用Verilog HDL 语言自顶向下的设计方法设计多功能数字钟，突出了其作为硬件描述语言的良好的可读性、可移植性和易理解等优点，并通过Altera QuartusⅡ 4.1 和ModelSim SE 6.0 完成综合、仿真。此程序通过下载到FPGA 芯片后，可应用于实际的数字钟显示中。 关键词：Verilog HDL；硬件描述语言；FPGA Abstract: In this paper, the process of designing multifunctional digital clock by the Verilog HDL top-down design method is presented, which has shown the readability, portability and easily understanding of Verilog HDL as a hard description language. Circuit synthesis and simulation are performed by Altera QuartusⅡ 4.1 and ModelSim SE 6.0. The program can be used in the truly digital clock display by downloading to the FPGA chip. Keywords: Verilog HDL；hardware description language；FPGA
上传时间： 2013-11-10
上传用户：hz07104032
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC Circuit as an example, an equivalent Circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of Circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, Circuitlayout and magnetic component design are modified to minimize Circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the Circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of theCircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several Circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上传时间： 2013-11-16
上传用户：萍水相逢
|Introduction Basic Concept Tips to layout Power Circuit Type of Power Circuit Basic Concept Maximum Current calculation Resistance of Copper ideal power supply & noise Capacitor & Inductor Power consumption Function of power Circuit
上传时间： 2013-12-10
上传用户：JIEWENYU
This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上传时间： 2014-01-24
上传用户：s363994250
阻抗匹配 阻抗匹配（Impedance matching）是微波电子学里的一部分，主要用于传输线上，来达至所有高频的微波信号皆能传至负载点的目的，不会有信号反射回来源点，从而提升能源效益。 大体上，阻抗匹配有两种，一种是透过改变阻抗力（lumped-Circuit matching），另一种则是调整传输线的波长（transmission line matching）。 要匹配一组线路，首先把负载点的阻抗值，除以传输线的特性阻抗值来归一化，然后把数值划在史密夫图表上。 把电容或电感与负载串联起来，即可增加或减少负载的阻抗值，在图表上的点会沿著代表实数电阻的圆圈走动。如果把电容或电感接地，首先图表上的点会以图中心旋转180度，然后才沿电阻圈走动，再沿中心旋转180度。重覆以上方法直至电阻值变成1，即可直接把阻抗力变为零完成匹配。 由负载点至来源点加长传输线，在图表上的圆点会沿著图中心以逆时针方向走动，直至走到电阻值为1的圆圈上，即可加电容或电感把阻抗力调整为零，完成匹配.........
标签： 阻抗匹配
上传时间： 2013-10-20
上传用户：ZOULIN58
西门子建筑电器-电气安装技术部发行的各类产品样本：小型断路器、剩余电流保护断路器和模数化产品(中/ 英文)Miniature Circuit-Breakers, Residual Current Operated Circuit-Breakers and Modular Devices (Chinese/English)低压熔断器系统(中/ 英文)Fuse System (Chinese/English)雷击，过电压－不再是问题(中文)Thunderstorms - no problem (Chinese)西门子建筑电器目录(中文)Electrical Installation Technology Catalog (Chinese)终端配电保护产品(中文)5 IN 1 (Chinese)SIKUS 和 STAB UNIVERSAL 目录(中文)SIKUS and STAB UNIVERSAL Catalogue (Chinese)SIKUS HC 目录(中文)SIKUS HC Catalogue (Chinese)SentronTM 母线槽 (中文)SentronTM Busway System (Chinese)SentronTM 母线槽系统快速选型 (准备中) (中文)SentronTM Busway System quick selection (in preparing) (Chinese)建筑低压配电一体化解决方案－住宅小区应用(中文)Building LV PD Solution (Chinese)西门子 DELTA vista“远景”系列开关和插座价目表(中文)Delta vista Switch and Socket Pricelist (Chinese)instabus EIB 面向未来的楼宇智能控制系统(中文)instabus EIB (Chinese)instabus EIB 面向未来的楼宇智能控制系统技术手册 (准备中) (中文)instabus EIB technical handbook (in preparing) (Chinese)西门子电气安装技术业绩卓越(中/ 英文)ET Reference Manual (Chinese/English)
上传时间： 2013-11-23
上传用户：瓦力瓦力hong
