A Computer-On-Module, or COM, is a Module with all components necessary for a bootable host computer, packaged as a super component. A COM requires a Carrier Board to bring out I/O and to power up. COMs are used to build single board computer solutions and offer OEMs fast time-to-market with reduced development cost. Like integrated circuits, they provide OEMs with significant freedom in meeting form-fit-function requirements. For all these reasons the COM methodology has gained much popularity with OEMs in the embedded industry. COM Express® is an open industry standard for Computer-On-Modules. It is designed to be future proof and to provide a smooth transition path from legacy parallel interfaces to LVDS (Low Voltage DIFFERENTIAL Signaling) interfaces. These include the PCI bus and parallel ATA on the one hand and PCI Express and Serial ATA on the other hand.
上传时间： 2013-11-04
上传用户：Wwill
Single-Ended and DIFFERENTIAL S-Parameters DIFFERENTIAL circuits have been important incommunication systems for many years. In the past,DIFFERENTIAL communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe DIFFERENTIAL networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with DIFFERENTIAL circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses DIFFERENTIAL and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间： 2014-03-25
上传用户：yyyyyyyyyy
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： 2013-10-27
上传用户：jyycc
Calculation of the DIFFERENTIAL Impedance of Tracks on FR4 substrates There is a discrepancy between calculated and measured values of impedance for DIFFERENTIAL transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating DIFFERENTIAL impedance.
上传时间： 2013-10-18
上传用户：masochism
用JAVA语言编写，包括PSO（Particle swarm optimization, 中文译名为粒子群优化或微粒群算法), DE (DIFFERENTIAL evolution, 中文译名为差分进化或差异演化)等算法，有一些不带约束和带约束的算例（如Michelawicz的几个问题）。使用说明见usage.txt、RUNExample.bat和程序中的注释。
上传时间： 2014-01-06
上传用户：agent
The purpose of this application note is to describe the main elements of an RS-422 and RS-485 system. This application note attempts to cover enough technical details so that the system designer will have considered all the important aspects in his data system design. Since both RS-422 and RS- 485 are data transmission systems that use balanced DIFFERENTIAL signals, it is appropriate to discuss both systems in the same application note. Throughout this application note the generic terms of RS-422 and RS-485 will be used to represent the EIA/TIA-422 and EIA/TIA-485 Standards.
标签： application describe elements purpose
上传时间： 2013-12-28
上传用户：sxdtlqqjl
CLAWPACK is a software package designed to compute numerical solutions to hyperbolic partial DIFFERENTIAL equations using a wave propagation approach
标签： hyperbolic numerical solutions CLAWPACK
上传时间： 2014-01-02
上传用户：woshini123456
matlab 求解微分方程 ，This module Does FEM analysis of a field problem when the Governing DIFFERENTIAL equation
上传时间： 2016-06-02
上传用户：二驱蚊器
数值分析算法源码(java) 这个学期一边学习java一边学习数值分析,因此用java写了一个数值分析算法的软件包numericalAnalysis. [说明] 适合使用者:会java的,想要学习数值分析算法的人. 本代码对照书:数值分析第二版,史万明等编,北京理工大学出版社. 本代码尽量按书中描述的来写,可以提供参考. [使用方法] 在java的ide中新建一个项目,把numericalAnalysis包直接拷贝到此项目的源文件夹中,然后要解决什么问题,就相应的编译运行什么包. 另外有这些类的API提供参考,可以自己根据自己要求写驱动类.运行API文件夹中的index.html文件就行. [包的结构] numericalAnalysis包中又含有9个包,除function包的是接口外,其余包都含有一个独立的数值分析问题的类以及其驱动类.9个包如下: DIFFERENTIAL:微分问题 equation:方程 function:只含一个接口,用来让用户写自己的函数 functionApproximation:离散情况下函数逼近问题 integration:积分问题 interpolation:插值问题 linearEquationGroup:线性方程组问题(包括过定方程组) norm:求解向量和矩阵的范数 ode:常微分方程数值解的求解
标签： java numericalAnalysis 数值分析 算法
上传时间： 2014-01-03
上传用户：wff
Toolbox for Numerical Computing with MATLAB （by Cleve Moler). Numerical Computing with MATLAB （by Cleve Moler) is a textbook for an introductory course in numerical methods, Matlab, and technical computing. The emphasis is on in- formed use of mathematical software. We want you learn enough about the mathe- matical functions in Matlab that you will be able to use them correctly, appreciate their limitations, and modify them when necessary to suit your own needs. The topics include * introduction to Matlab, * linear equations, * interpolation, * zero and roots, * least squares, * quadrature, * ordinary di?erential equations, * random numbers, * Fourier analysis, * eigenvalues and singular values, * partial DIFFERENTIAL equations.
标签： Numerical Computing MATLAB with
上传时间： 2014-01-01
上传用户：guanliya
