东莞理工学院试题专业英语作业题.doc

穗杰纯手打1.1 Many of the products and services in modern society are based upon the work of electrical engineers and computer scientists. The tremendous reduction over the last decade in the cost of digital electronic devices has led to an explosive growth in the use of computers and computation. At the same time, our increased understanding of computer science has made possible the development of new software systems of increased power, sophistication, and flexibility.翻译：现代社会的许多产品和服务都是建立在电气工程师和计算机科学家的工作基础之上。在过去几十年中，数字电子器件成本的大幅下降已经带来了计算机应用迅猛的增长。与此同时，人们对计算机科学认识的提高使得开发新的更强大、更复杂、更灵活的软件系统成为可能。1.4 Memory is the component of a computer(and an embedded system) that is used to store and retain information. There is always need to store information in an embedded application, so there will always be some type of memory in the design. Many types of memory are available, thus there are many choices for embedded customers.翻译：存储器是计算机和嵌入式系统中用来保存信息的部件。在嵌入式应用中需要存储信息，影驰设计中总含有某种类型的存储器。现在有许多种可以利用的存储器件，因此对于嵌入式用户存在多种选择。1.6现代电子系统的数字化程度越来越高，复杂程度也极高，要死没有超大规模芯片技术，只是无法想象的。闲的电子系统太复杂了，以致其设计原理很像大型软件系统设计。计算机科学和电子系统设计所需的背景知识存在许多相同之处，而现代电子系统-这个不断扩展的工程领域-也离不开计算机辅助设计。翻译：Modern electronic systems are increasingly digital in nature, exceedingly complex,and would be inconceivable without todays VLSI chip technology. Indeed,such systems are so complex that the principles of their design bear great similarities to system design require similar backgrounds in many respects, and computer aids to design are essential in this ever-expanding domain of engineering.1.10在计算机系统中，存储器是用于程序运行和数据存储的部件。随机存取存储器芯片构成了计算机主存储器。可用存储器的容量决定了运行程序的大小和一次能否运行多个程序。主存储器只是暂时储存数据。一旦关闭计算机，数据就丢失了。它不同于内部只读存储器和外部存储器，后者的数据保存时间更为长久。只读存储器中包含着计算机的核心程序。总之任何以机器可读方式存储数据的设备都是存储器。翻译：Memory is the part of a computer system that is used to run programs and store data. The main memory is built from Random Access Memory(RAM) chips. The amount of memory available determines the size of programs that can be run, and whether more than one program can run at a time. Main memory is temporary, and the internal Read Only Memory ( ROM ), and external storage. ROM contains the computers essential programs In the general sense, Memory can be any device that can hold data in machine-readable format.2.2The same definition of DRcan be used for an op amp, and the maximum output voltage swing equals Voumax. This output voltage swing is defined as the maximum output voltage the op amp can achieve (Voh) minus the minimum output voltage the op amp can achieve (Vol). Voh and Vol are easily obtainable from an op amp IC data sheet.翻译：这个“动态范围”的定义也可用于运算放大器，其最大输出电压摆幅Voutmax。输出电压摆幅定义为运算放大器能达到的最大输出电压（Voh）减去最小输出电压（Vol）。从运放集成电路数据手册中，可以很容易获得Voh和Vol。2.5 Chip package is the housing that chips come in for plugging into (socket mount) or soldering onto (surface mount) the printed circuit board. Creating a mounting for a chip might seem trivial to the uninitiated, but chippackaging is a huge and complicated industry. The ability to provide more and more I/O interconnections to a die (bare chip ) that is increasingly shrinking in size is an ever-present problem. In addition, the smaller size of the package contributes as much to the miniaturization of cell phones and other handheld devices as the shrinking of the semiconductor circuits.翻译：芯片封装就是芯片的外罩。有了它，才能把芯片插入（插座安装）或焊至（表面安装）印制电路板上。在外行看来，芯片安装设计似乎不大重要;事实上芯片封装技术却是一个庞大、复杂的行业。为尺寸不断缩减的电路小片（裸片）提供越来越多的“输入/输出互连”能力是经常出现的问题。除此之外，封装和半导体电路的“缩微化”均有助于减小蜂窝电话和其他手持设备的尺寸。2.7在电子技术各领域中，欧姆定律都是基本定律。欧姆定律可表达为V=I*R。欧姆定律可应用于单个器件、一组器件或一个完整电路。当已知流过电路中各部分的电流时，其电压降可由电阻和电流的乘积获得。翻译：Ohms law is stated as V=IR, and it is fundamental to all electronics. Ohms law can be applied to a single component , to any group of components, or to a complete circuit. When the current flowing through any portion of a circuit is known, the voltage dropped across that portion of the circuit is oobtained by multiplying the current times the resistance.2.9噪声限定了系统可以处理的数据和信号。噪声降低了放大器、接收器等设备辨别信号的能力因为噪声和输入信号混合起来。运算放大器产生的噪声、电阻噪声和电源噪声决定论能够恢复和测量的信号大小。翻译：Noise sets a limit on the information and signals that can be handled by a system. The ability of an amplifier, receiver, or other device to discern a signal is degraded by noise. Noise mixed with the incoming signal, noise generated by the op amp, resistor noise, and power supply noise ultimately determine the size of the signal that can be recoverd and measured.2.10巴特沃斯（即“最大平坦”）滤波器是最常见的通用滤波器。在巴特沃斯滤波器的通带内，衰减单调变化到3dB点（即人们熟知的特征频率点）。不论是几阶巴特沃斯滤波器，这个特征频率点都是相同的。不过，随着滤波器阶数的增加，通带滚降会更接近特征频率点，而在特征频率点和阻带之间的过渡区域滚降也会更陡。翻译：A Butterworth (maximally flat) filter is the most commonly used general-purpose filter. It has a monotonic passband with the attenuation increasing up to its 3dB point, which is known as the natural frequency. This frequency and the roll-off in the transition region between the natural frequency and the stopband becomes sharper.3.4 IBIS(I/O Buffer Information Specification) is a format for defining the analog characteristics of the input and output of integrated circuits. IBIS models are ASCII files that provide the behavioral information tequired to model the device without divulging the proprietary design of the circuit.翻译：IBIS(输入/输出缓冲规范)是一种用来对集成电路输入/输出模拟特性进行定义的格式。IBIS模型是ASCII文件。在不泄露电路设计专利的前提下，IBIS模型提供了对器件建模所需的行为信息。3.5In multiconductor systems, excessive line-to-line coupling, or crosstalk , can cause two detrimental effects. First, crosstalk will change the performance of the propagation velocity. Additionally, crosstalk will induce noise onto other lines. These aspects of crosstalk make system performance heavily dependent on data patterns, line-to-line spacing, and switching rates.翻译：在多导线系统中，导线间的过量耦合（即“窜扰”）会引发两种有害效应。首先，窜扰改变了总线中传输线的有效特性阻抗和传输速度，从而使总线传输线的性能发生改变。此外，窜扰将噪声感应到其他导线上。串扰现象的这些特点使得系统性能严重地依赖于数据模式、导线间距和切换速率。3.6晶体是一种含有统一排列分子的透明石英材料。翻译：Crystal is a transparent quartz material that contains a uniform arrangement of molecules.3.7随着高速数字系统变得越来越复杂，时序和信号完整性的实现也越来越困难。翻译：As high-speed digital systems become more complex, it is becoming increasingly difficult to manage timings and signal integrity.3.8窜扰是两条导线间的能量耦合。但不同结构的电磁场相互作用时，窜扰就会发生。翻译：Crosstalk is thhe coupling of energy from one line to another. It will occur whenever the electromagnetic fields from different structures interact.3.10许多系统工作在高频上，导体在这些频率上不再仅仅表现为导线，而是展现出高频效应并表现为传输线。如果没有正确处理这些传输线，就可能在无意中破坏力系统时序。翻译：Many systems operate at high frequencies at which conductors no longer behave as simple wires, but instead exhibit high-frequency effects and behave as transmission lines. If these transmission lines are not hhandled properly, they can unintentionally ruin system timing.4.1The available spectrum bandwidth is shared in a number of ways by various wireless radio links. The way in which this is done is referred to as a multiple access scheme. There are basically four principle schemes. These are frequency division multiple access (FDMA), time division multiple access (TDMA),code division multiple access (CDMA), and space division multiple access (SDMA).翻译：不同的无限射频链路以不同的方式共用频谱带宽。这些共用方式称为“多址模式”。“频分多址”(FDMA)、“时分多址”（TDMA）、“码分多址”（CDMA）和“空分多址”（SDMA）是四种主要的多址模式。4.2The area served by mobile phone systems is divided into small areas known as cells. Each cell contains a base station that communicates with mobiles in the cell by transmitting and receiving signals on radio links. The transmission from the base station to a mobile is typically referred to as downstream, forwardlind, or downlink. The corresponding terms for the transmission from a mobile to the base are upstream, reverse-link, and uplink. Each base station is associated with a mobile switching center (MSC) that connects calls to and from the base to mobiles in other cells and the public switched telephone network.翻译：移动电话系统的服务区划分为一个个“蜂窝”小区。每个“蜂窝”小区都有一座基站；通过在无线链路上发送、接收信号，基站和“蜂窝”内移动用户通信。基站向移动用户发送信号称作“前向链路”或“下行链路” 。移动用户向基站发送信号称作“反响链路”或“上行链路”。每个基站都要和“移动交换中心”(MSC)联络，而MSC的作用是把来往于基站的呼叫和其他蜂窝的移动用户、公共交换电话网连接起来。4.3A base station communicates with mobiles using two types of radio channels, control channels to carry control information and traffic channels to carry messages.翻译：基站使用两类无线信道和移动用户进行通信：传送控制信息的“控制信道”和传送消息的“通信信道”。 4.6“信道”这个术语通常是指频分多址系统中的一个频率，时分多址系统中的一个时隙，码分多址系统中的一个代码或混合系统中频率、时隙、代码的某种组合。翻译：The generic term channel is normally used to denote a frequency in FDMA system, a time slot in TDMA system, and a code in CDMA system or a combination of these in a mixed system.4.7在频分多址和时分多址系统中，一旦信道（频率或时隙）分配给用户，该信道在非活动期间也不能被利用。翻译：In FDMA and TDMA systems once a channel (frequency and/or time slot ) is allocated to a user, that channel cannot be used during nonactivity periods.4.8“蜂窝”概念是由贝尔实验室发明的。1983年10月，在芝加哥出现第一个商用模拟语音系统。翻译：The cellular concept was invented by Bell Laboratories and the first commercial analog voice system was introduced in Chicago in October 1983.5.1 Some digital logic ICs and their analog counterparts (analog/digital converters, for example) are standard parts, or standard ICs. You can select standard ICs from catalogs and data books and buy them from distributors. Systems manufacturers and designers can use the same standard part in a variety of different microelectronic systems (systems that use microelectronics or ICs).翻译：有些数字逻辑集成电路和模拟集成电路（如模数转换器）是标准器件或者标准集成电路。可以从产品目录和数据手册当中选择标准集成电路，从经销商处购买。系统制造商和设计人员可以在各种不同的微电子系统（“微电子系统”是指应用微电子技术和集成电路的系统）中使用相同的标准器件。5.3An ASIC (Application Specific Integrated Circuit) is a chip that is custom designed for a specific application rather than a general-purpose chip such as a microprocessor. The use of ASICs improves performance over general-purpose CPUs, because ASICs are “hardwired” to do a specific job and do not incur the overhead of fetching and interpreting stored instructions. An ASIC chip performs an electronic operation as fast as it is possible to do so ,providing, of cours ,that the circuit design is efficiently constructed.翻译：“专用集成电路”不是微处理器这样的通用芯片，而是一种特殊用途设计的定制造芯片。和通用CPU相比，使用专用集成电路可以提高性能。因为换用集成电路是使用“硬连线”完成具体工作的，并不需要为取指令和解释指令付出开销。专用集成电路芯片能够尽可能快的速度完成一项电子操作；当然，其电路设计应该具有高效的结构。5.6“电子设计自动化”就是利用计算机对芯片上的电子线路进行功能设计和仿真。翻译：EDA (Electronic Design Automation) uses the computer to design and simulate the performance of celctronic circuits on a chip.5.9“复杂可编程逻辑器件”是一种在逻辑模块之间具有可编程互连的可编程逻辑器件。多数复杂可编程器件是基于电可擦写可编程只读存储器和闪存的。翻译：CPLD(Complex PLD) is a programmable logic device that includes a reprogrammable interconnect between the logic blocks. CPLDs are mostly EEPROM and flash based.6.1 The primary reason for processing real-world signals is too extract information from them. This information normally exists in the form of signal amplitude (absolute or relative), frequency or spectral content, phase ,or timing relationships with respect to other signals. Once the desired information is extracted from the signal, it may be used in a number of ways.翻译：“提取信息”是对现实世界信号进行处理的主要原因。通常，信息的存在形式是信号幅度（绝对幅度或相对幅度）、频率（或频谱成分）、相位（或者和其他信号之间的时序关系）。一旦把有用信息从信号中提取出来，就能以多种方式使用这些信息。6.3Another requirement for signal processing is to compress the frequency content of the signal (without losing significant information )them format and transmit the information at lower data rated, thereby achieving a reduction syst