第一篇:数控机床专业英语
数控机床专业英语
Unit 1
The history of CNC and NC development 电脑数字控制和数字控制的发展历史
Dialogue
对话
Topical introduction :Tom and Mary have now just finished a class given by professor Smith on the workings of the machine tools.yet, they still have some questions, and so, they walk over to prof.smith.主题介绍:汤姆和玛丽刚刚在史密斯教授的指导下完成了机床运行方式的课程。然而,他们仍然有一些问题。于是他们步行到史密斯教授那里。
Tom:(to prof.Smith)Excuse me, sir, I’m Tom, one of your students in this class.Could I ask you some questions? 汤姆(对教授说):对不起,先生。我是汤姆,是你班中的一名学生。我可以问你一些问题吗?
Smith:(to Tom):Why not? Come on, then.史密斯:(对汤姆说)为什么不行呢?来吧。
Tom: Why do we name these machines numerical control machines? 汤姆:为什么我们(课程)的名字为数字控制机床
Smith: A good question, boy.You know, uh-hm… NC, or numerical
control, actually refers to the control of a machine tool or any other processing machines by using a series of mathematical information, or numerical data.It means the work of machine is controlled by a numerical control program.史密斯:这是个好问题,你知道NC或者数字控制,实际上是指机床的控制或者通过使用一系列数字信息和数据资料控制机床加工过程。Mary: Oh, Porf.Smith, the idea is nice enough.But what is the advantage of numerical control over the hand control? Isn’t our hand more sensible or reliable than the programmed data? 玛丽:史密斯教授,这个想法相当好。但是数字控制与人工控制相比优势什么?人工控制不是能比程序化的数据更合理 和可靠吗? Smith: In some ways, yes, A good example is some fine works, like a jade box, but the qualities of hand-made products may not be consistent or stable.What is more important, NC has proved to be much more advantageous in overall operation.史密斯:在一些方面,确实如此,象玉雕等精细的工作就是很好的例子,但是手工制作的产品的质量也许不能够一致或者稳定。更重要的是,NC(系统)已经证明在总体的操作上有更多的优势。Mary: But what do you mean by overall operation?
玛丽:可是通过总体的操作你要表达什么意思呢?
Smith: Uh-huh, by it we mean the general industrial production practice.For example, NC should be adopted whenever there is
similar raw material and work parts are produced in various sizes and complex shapes.Those production shops that may have frequent changeovers will surely benefit from NC programs.史密斯: 总体的操作是指总体的工业生产实际。例如,在同样的原材料和工序时制造出不同尺寸规格和复杂形状(零件)的场合NC系统将会被采用。当工厂遇到计划改变时将会通过NC程序获得稳定的收益。
Tom: Thank you,prof.Smith, but I have another question.How can we use NC to get more satisfactory results in the real production?
汤姆:谢谢,史密斯教授。但是我有另一个问题。怎样能够使用NC 在实际生产中获得更加满意的结果?
Smith: It’s better to use NC tools together with other technical advances, such as programmed optimization of cutting speeds and feeds, work positioning, tool selection, an chip disposal.史密斯:与其它技术一起使用将是更好的发展,例如切削速度和吃刀量的程序优化,运算位置,刀具选取,和排销。
Tom & Mary: Thank you prof.Smith, NC sounds really promising from what we say.汤姆和玛丽:谢谢史密斯教授,从我们的谈话中表明NC发出的信号确实很有前途。
Text
The History of CNC and NC Development
计算机数字控制(CNC)和数字(NC)控制的发展历史
Numerical Control(NC)is any machining process in which the operations are executed automatically in sequences as specified by the program that contains the information for the tool movements.The NC concept was proposed in the late 1940s by John Parsons of Traverse City, Michigan.Parsons
recommended a method of automatic machine control that would guide a milling cutter to produce a “thru-axis curve” in order to generate smooth profiles on work pieces.数字控制是是按照含有机床(刀具)运动信息程序所指定的顺序自动执行操作的加工过程。数字控制的概念是由密歇根州的约翰.帕森在40年代末提出的。为了在工件上加工光滑的轮廓,帕森提出了一种自动的机床控制方式,它能够引导铣床刀具加工出一种“过轴曲线”。
In 1949, The U.S.Air Force awarded Parsons a contract to develop a new type of machine tool that would be able to speed up production methods.Parsons commissioned the Massachuestts Institute of Technology(M.I.T)to develop a practical
implementation of his concept.Scientists and engineers at M.I.T built a control system for a tow-axis milling machine
that used a perforated paper tape as the input media.In a short period of time, all major machine tool manufacturers were producing some machine with NC, but it was not until the late 1970s that computer-based NC became widely used.NC matured as an automation technology when inexpensive and powerful microprocessors replaced hand-wire logic-making
computer-base NC systems.When Numerical Control is performed under computer
supervision, it is called Computer Numerical Control(CNC).Computer are the control units of CNC machines, they are built in or linked to the machine via communications channels.When a programmer input some information in the program by tape and so on, the computer calculates all necessary data to get the job done.On the first numerically controlled(NC)machine, numerical data was controlled by tape, and because of that, the NC systems were known as tape-controlled machines.They were able to control a single operation entered into the machine by punched or magnetic tape.There was no possibility of editing the program on the machine.To change the program, a new tape had to be made.Today’s systems have computers to control data;they are
called Computer Numerically Controlled(CNC)machine.For both NC and CNC systems, work principles are the same.Only the way in which the execution is controlled is different.Normally, new systems are faster, more powerful, and more versatile.
第二篇:数控机床2014(推荐)
试卷代号:243 1中央广播电视大学2013-2014学第一学期“开放专科”期末考试
数控机床试题
一、单项选择题(15道题,每小题3分,共45分)
1.(C)属于数控机床的机床本体。A.自动换刀装置B.伺服电机C.进给机构D.脉冲编码器
2.滚珠丝杠螺母副消除间隙的主要目的是(B)。A.减小摩擦力矩B.提高反向传动精度和轴向刚度C.增大驱动力矩D.提高使用寿命
3.按照运动轨迹控制分类,数控钻床属于(A)。A.点位控制B.轮廓控制C.直线控制D.远程控制
4.对箱体类,异形类,型腔模具工件,如果加工余量小(精加工),而且以单面孔系加工为主,工序集中的,一般选用(C)进行加工。A.卧式加工中心B.数控车床C.立式加工中心D.车削中心
5.(C)是数控系统和机床本体之间的电传动联系环节。A.控制介质B.反馈装置C.伺服系统D.辅助装置
6.数控机床的液压系统的控制属于机床的逻辑控制,由(D)完成。A.脉冲编码器B.数控装置C.伺服驱动控制器D.可编程控制器
7.位置检测劳置是位置控制闭环系统的重要组成部分,是保证数控机床(A)的关键。A.精度B.稳定性C.效率D.速度
8.图1所示卧式加工中心的自动换刀装置采用的是(A)换刀方式。A.机械手B.刀库式C.成套更换方式D.转塔式
9.加工中心最突出的特征是是设置有(B),并能自动换刀。A.自动排屑装置B.刀库C.自动交换工作台D.主轴准停装置
10.ATC是(A),数控机床采用其后数控加工的辅助时间主要用于工件的安装和调整。A.自动换刀系统B.自动托盘交换系统C.自动排屑系统D.自动冷却系统
11.下列(D)检验属于定位精度检验。A.主轴轴向及径向跳动B.主轴在Z轴方向移动的直线度C.X、Y、Z坐标轴的相互垂直度D.直线运动轴机械原点的返回精度
12.液压和气动装置在数控车床中不能用于(A)。A.交流伺服电机的控制B.尾架套筒的顶出和退回C.主轴高低速的换挡D.卡盘的夹紧与放松
13.数控电火花加工机床的加工局限性有(D)。A.电火花加工属不接触加工B.易于实现加工过程自动化C.加工过程中没有宏观切削力D.只能用于加工金属等导电材料
14.加工中心按照功能特征分类,可分为(C)、钻削和复合加工中心。A.刀库十主轴换刀B.卧式C.镗铣D.三轴
15.数控机床的故障按故障特征分类,可分为(B)和有报警故障两大类。A.随机性故障B.无报警故障C.可恢复性故障D.机械故障
二、判断题(5道题,每小题2分,共10分)
16.(√)数控机床是为了解决单件、小批量、精度高、形状复杂的零件加工的自动化要求而产生的。17.(×)数控机床加工的加工精度比普通机床高,是因为数控机床的传动链较普通机床的传动链长。
18.(×)数控机床工作的环境温度是没有限制条件的。19.(√)数控系统是数控机床实现自动加工的核心。20.(×)液压装置工作速度快和工作频率高,对环境要求适应性好,装置结构简单,工作
介质不污染环境。
三、简答题(3道题,共25分)
21.数控机床常见的导轨类型有哪几种?(5分)答:数控机床的导轨类型有滑动导轨、滚动导轨和静压导轨等
22.简述数控机床机械结构的主要特点。(10分)答:(1)高的静、动刚度;(2)良好的抗振性能;(3)良好的热稳定性;4)高的灵敏度;(5)高效化装置、高人性化操作。
23.与普通机床相比较,数控机床的主传动系统的特点有哪些?(10分)
答:1)转速高、功率大;(2)变速范围宽;(3)主轴变换迅速可靠;(4)主轴组件的耐磨性高
四、综合题(共20分)
图2为CJK1640型数控车床外形图,图3为CK7525型数控车床外形图,识图并回答下
列问题。
24.图2中的CJK1640型数控车床和图3中的CK7525型数控车床,按数控系统的功能分类,各属于什么类型的数控车床?(4分)A)经济(2分);(B)全功能。(2分)(A)图2中的CJK1640型数控车床属于一型数控车床
(B)图3中的CK7525型数控车床属于型数控车床
25.图2中的CJK16 40型数控车床,这种类型的数控车床的特点是什么?(3分)
答:经济型数控车床一般是在普通车床的基础上进行改进设计,并采用步进电动机驱动的开环伺服系统。其控制部分采用单板机、单片机或档次比较低的数控系统来实现。此类车床结构简单,价格低廉。但功能简单
26.图3中的CK7525型数控车床,这种类型的数控车床的特点是什么?(3分)
答:全功能型数控车床控制系统是标准型的,带有高分辨率的CRT显示器以及各种显示、图形仿零点、刀具补偿等功能,而且具有通信或网络接口。全功能型数控车床采用闭环或半闭环控制的伺服系统,可以进行多个坐标轴的控制,并有高刚度、高精度和高效率等特点。
27.从床身结构上看,这两个数控机床的结构布局有什么不同?各自的特点是什么?(10分)
答:(1)图1中的CJK1640型数控车床,采用水平床身。(2分)图2中的CK7525型数控车床,采用倾斜床身。(2分)(2)水平床身特点:是加工工艺性好,其刀架水平放置,有利于提高刀架的运动精度,但这
种结构床身下部空间小,排屑困难。(3分)
倾斜床身特点:①机床外形美观,占地面积小; ②易于排屑和冷却液的排流;③便于操作者操作和观察;④易于安装上下料机械手,实现全面自动化; ⑤可采用封闭截面整体结构,以提高床身的刚度。(3分)
第三篇:专业英语
我国经济和科学技术正在高速发展,随着我国机械行业实力的不断提升,中国正在加速产品与设备的更新与改造,我国与其他国家在各技术领域也正在实现进一步的合作,许多企业引进了很多进口设备,大量资料是英文原版的。因此,学生将来在工作岗位上能否读懂这些资料就是摆在面前的一个严峻的问题,特别是在生产实际中碰到现场实际问题的时候,很可能需要查阅原版英文资料或与相关专家用英语交流专业技术来谋取解决途径,所以机械工程专业英语的掌握就变得越来越重要。
一、学习机械专业英语面临的主要问题
1.缺乏足够的重视,认为没必要
许多学生对专业英语重视不够,认为自己以后在工作岗位上一般用不上,学起来又不容易,不想花功夫去学习和加强专业英语方面的能力,即便有专业英语课程也是抱着及格万岁的思想,敷衍了事。其实,随着社会的发展,各种工作岗位对人才的要求越来越高,即使作为一名操作工,也有很大可能要面对纯英文的说明书、加工图纸等专业文献,更无须说将来担任管理和领导岗位对专业英语的需求了。
2专业基础知识不扎实
专业基础不扎实、专业知识的缺乏是专业英语学习和翻译的一大障碍。只有既懂外语又懂专业的人才能适应全面的对外开放,4.无法适应专业英语本身的特点
专业英语一般内容较为枯燥,阐述的是原理概念,结构严谨,不注重文字修饰,重在客观事实;专业词汇多,逻辑性强,理论推导多,有独特的文体形式和表达方式。在学习开始阶段,我感觉很难适应。
二、大学生学好机械专业英语的方法
1.把握专业知识
必须将机械专业知识与英语知识相结合。缺乏专业知识,翻译专业文献就没有了根基,成了无本之末。也许自己在学习过程中就会对翻译出来的东西拿捏不稳,或者自己都不明白,更不能保证对错了。所以,学生必须加强开设本课程前的相关专业知识的学习,为本课程的学习扫清这方面的阻碍,减轻负担。也有学生反映,专业英语学完以后,英语和专业两方面都有所巩固和加强,所以学生要做的仍旧是树立信心,保持良好积极的心态。
2.积累专业词汇和专业术语
在专业英语的学习过程中,学生既要巩固基础词汇,也要学习专业词汇,更要注重基础词汇的习惯用法、含义和在专业英语中的特殊用法、含义,同时,学生还需要在识记专业词汇的同时,掌握一定量的词根、词缀[7]。提高专业英语资料的阅读能力必须扩大词汇量,掌握一定量的专业词汇。如果词汇量掌握得不够,阅读时就会感到生词多,障碍大,不但影响阅读的速度,而且影响理解的程度,从而不能进行有效的阅读,还容易使人产生挫败感。而学生要想扩大词汇量,就必须在阅读的同时进行识记,并扩大阅读范围。
3培养浓厚兴趣
培养对英语的兴趣至关重要。“兴趣是最好的老师”,兴趣是学习英语的巨大动力,有了兴趣,学习就会事半功倍。我们都有这样的经验:喜欢的事,就容易坚持下去;不喜欢的事,是很难坚持下去的。而兴趣不是与生俱来的,需要培养。必须要用正确的态度对待英语学习,用科学的方法指导学习。多让自己去尝试,通过努力让自己体会成功的愉悦。
三、结语
用英语进行专业交流是学习机械工程专业英语的最终目的。由于翻译过程是个创造性的、从生疏到熟练的过程,只有具备刻苦的精神、严肃认真的学习态度和一定的英语水平、专业水平和汉语表达水平,才能充分理解原专业文献的含义,把握原文的想要表述的实质内容,运用种种表达手段和翻译技巧,用准确流畅的符合汉语言习惯的语言生动地再现原文。所以,为把自己培养成为复合型、有发展后劲的高技能人才,大学生必须把握机械工程专业知识,培养专业英语的学习兴趣,积累专业英语学习方法和基础知识,加强英文原始专业文献的阅读,扩大知识面,迅速而切实地提高自己的专业英语的应用能力,为将来更好地适应高素质工作岗位和进一步发展的需要打下良好的基础。
第四篇:专业英语
土木工程翻译实例----现场质量控制样件概述 On-site Quality Control Samples
The Specialist contractor shall erect the first area of each type of the Works and offer these to the Project Manager as on-site quality control samples.The standard of workmanship for the Works shall be to an agreed standard established by the construction of the On-site Quality Control Samples.The Project Manager shall review and comment on the On-site Quality Control Samples.Should the specialist contractor wish to continue with installation of any of the Works before the Project Manager has reviewed and commented on the On-site Quality Control Samples, he shall do so at his own risk.The Project Manager may require parts of the sample to be dismantled to allow inspection of concealed details.Upon acceptance, the on-site control samples shall remain as part of the installed permanent Works.The Project Manager shall reject workmanship that falls below the accepted standard and shall require the specialist contractor to remove it and re-install it to the acceptable standard.现场质量控制样件
专业分包商应首先安装每种类型工程的第一个区域并将它作为现场质量控制样件提供给项目经理。把已通过审批的现场质量控制样件的施工标准作为工程的工艺标准。项目经理应对现场质量控制样件进行审查和评论。如果分包商想在以上步骤完成之前继续进行任何工程的安装,一切风险将由其自行承担。项目经理可以要求部分地拆除样件以检查隐蔽工程的详细节点。工程验收之后,现场质量控制样件仍然应作为永久工程的一部分。项目经理可以拒绝没有达到验收标准的工艺并要求专业承包商将其去除同时按照验收标准重新安装。
我的土木工程翻译----材料来源及其证书(摘于合同文件)
Compliance with Standards
Unless otherwise described, all materials shall conform to the appropriate current European or British Standard Specifications.The Specialist contractor shall provide the Project
Manager, on request, with guarantees, or certificates of conformity, from the prime material manufacturers and suppliers proving that the materials to be used do in fact conform to such specifications.These guarantees or certificates shall also confirm that the materials are suitable and appropriate for their intended use within the Works and will satisfy this Contract Document.遵从规范
除非有特别的说明,所有的材料均应符合相应的现行欧洲或英国规范。专业承包商应该按照要求把从原材料厂家和供应商那里获得的保证书或认证书递交项目经理用以证明即将使用的材料着实符合这类规范。这些保证书或认证书也应该确认这些材料在工程中的用途适当且合理,同时符合合同文件。
Sources of Materials
In accordance with the schedule of submissions, the Specialist contractor shall provide for the Project Manager’s review a list of the proposed materials and their sources.He shall also provide documents from the sources as evidence of their ability to carry out the tasks
expected of them, and written confirmation that the materials they are supplying are suitable and appropriate for their intended use and will satisfy this Contract Document.The Specialist contractor shall obtain the total quantity of each material from the same manufacturer.The Specialist contractor shall obtain materials from established and reputable
manufacturers, particularly those who are prepared to assist him with the design process, through to the fabrication and final installation on site.材料的来源 根据递交计划表,专业承包商应把含有提议使用材料的名称及其来源信息的列表递交项目经理审阅。专业承包商还应提供从材料供应商那里获得的相关文件以证明他们有能力完成其任务,以及书面确认用以证明这些材料在工程中的用途适当且合理,同时符合合同文件。
专业承包商应获得每种材料从同一个生产商购买的总数量。
专业承包商使用的材料应向知名的生产商购买。特别是他们完全能够从设计、装配到现场安装整个过程中给与承包商支持。
土木工程翻译----白令海峡大桥的简介摘录
第一次知道白令海峡大桥是在上大学的时候桥梁课老师梁力给我们播放了《Discovery》中一集专门介绍它的视频,我被它的壮观,雄伟所震撼,今天突然想到了这座“坚强”撼世之桥,特意把它的资料找了出来,并把其中一小段翻译出来和大家一起分享。
Bering Strait bridge
白令海峡大桥的简介摘录
Technical challenges技术挑战
The route would lie just south of the Arctic Circle, subject to long, dark winters and extreme weather(average winter lows 20°C with possible lows approaching 50°C).Maintenance of any exposed roadway would be difficult and closures frequent.Even maintenance of enclosed roadways and pipelines could also be affected by winter weather.Ice breakup after each winter is violent and would destroy normal bridge piers.Specially shaped massive piers along the ocean floor would be needed to keep the bridge stable.The Confederation Bridge between Prince Edward Island and New Brunswick addresses similar concerns on a much smaller scale.桥的路线正好位于北极圈的南端,它受到了漫长黑暗的冬季和极限天气的影响(冬天的平均温度低至20°C而且最低的温度甚至可能达到50°C)。任何暴露在外的路面部分的维护工作都是很困难进行的,所以不得不频繁地将其关闭。即使是关闭的路面和管线的维护也将受到冬季气候的影响。在冬天过后冰的消融也会是危险强烈的并且会对普通的桥墩造成毁灭性的破坏。这就需要沿着海床布置具有特殊形状的大桥墩以保证桥的稳定性。位于爱德华王子岛和新布朗斯威克之间的联邦大桥就面临着类似的问题,只不过它受影响的范围要小得多。
The United States and Canada use the British and now world standard gauge(4 feet, 8.5 inches wide)rails, while Russia uses Russian broad gauge(5 feet wide)tracks, a
break-of-gauge, and this would have to be addressed.A dual-gauge track network has been proposed, as those are used in some areas of Australia, whose rail network is split into different gauges.A cheaper solution is variable gauge axles or bogie exchange, as used at several places in the world already.美国和加拿大的铁路采用英国的也是现在的世界标准轨距(4英尺,8.5英寸宽),而俄罗斯的铁路采用俄罗斯宽轨距(5英尺宽),需要说明的是这样就形成了具有不同轨距的铁路。一个具有双轨距的铁路网方案被提了出来,这种方案正在澳大利亚某些地区使用,他们的铁路网就为存在不同的轨距。一个造价更低的解决方案就是使用变轨距车轮或转向车,这种方案已经在世界多个地方使用了。
土木工程翻译---施工安全
1、水平安全绳之设置,应依下列规定办理:
a、采用¢8.3钢丝绳,两端各用三个U型卡扣紧固在建筑物或构筑物牢固位置。
b、相邻两支柱间的安全绳限系挂一条安全带。
c、每条安全绳可系挂安全带之条数标示于绳锚锭端。
2、垂直安全绳之设置,应依下列规定办理: a、安全绳之下端应有防止安全带锁扣自尾端脱落之设施。
b、一条安全绳限供一名工人使用。
c、劳工作业或爬升位置之水平间距在一米以下者,得二人共享一条安全绳。
d、所有垂直安全绳应垂伸至地面/已完成楼板。
e、完成检验的安全带或安全绳皆应贴上下表所示的当月合格颜色标签,以利大家轻易分辨已完成检验的合格安全带。
f、在吊篮内施工,安全带必须系挂在安全绳自锁器上,不得系挂在除安全绳以外的任何地方。
g、施工人员应配备工具箱,将所用小附件装箱存放,小工具必须拴绳使用,防止高空坠落伤及人、物。临边物
料的摆放不得随意放置,要距离楼板边缘至少1米以上的安全位置,防止风吹或人碰落楼下,伤及人、物。h、摆放如玻璃、箱体等大件物体时,必须有安全保护措施,如大尺寸规格的玻璃(2.4平方米以上的)要求对
称摆放在玻璃架子两侧,并用绳子捆绑牢固,成箱的玻璃尽量集中存放,玻璃箱倾斜垫牢,并用木板将各木箱相连接,以免倒塌。
i、现场设置急救箱,在高温季节给工人发放防暑降温物品。
我的译文:
1.The setup of horizontal safety rope should comply with the followingprovisions:
a.¢8.3 wire rope should be applied.Three U-shaped claspsshould be used one both
ends to tighten onto the stable places on the buildingor structure.b.Only one safety belt could be tied on the safety rope between two adjacentstrut rods.c.The number of safety belt allowed to be tied should be marked on the head ofthe
rope’s anchor.2.The setup of vertical safety rope should comply with the following provisions:
a.At lower end of the safety rope, there should be facilities to prevent the fastener of safety
belt from falling off from the caudal end.b.One safetyrope should only be used by on worker.c.When horizontal distance between the operation or climbing position of workers iswithin one meter, one safety rope should be shared by two workers.d.All the vertical safety rope should draw down to ground/completed floor.e.The followingstick in colors should be stuck onto safety belts or safety ropes after test todisplay test passing of current month.In this way, qualified safety belt aftertest would be easy to recognize.f.During operation in basket, safety belt must be tied onto the self-lock of the safetyrope;tying onto any places besides safety rope is prohibited.g.Builder should be equipped with tool box.Small accessories should be kept in the boxand fastened to rope when in use to prevent from being dropped from height andhitting people or objects.Material and supplies at the edge of construction area should not be placed at will;more than one meter’s distance from the edgeof the floor is considered safe location for placing;in this way, droppingcaused by wind or man and hitting people or objects could be avoided.h.when big objects such as glass or boxes are placed, safety protection measures must becarried out.For example, glass of big dimensions(above 2.4 square meters)should be placed onto the two sides of the glass shelf with symmetry, and boundand fastened with rope.Glass in boxes should be placed together at one placeas much as possible.Boxes of Glass should be well padded to prevent fromslant.Wood-blocks should be used to joint all boxes to prevent from collapse.i.First-aidbox should be placed at construction site.Workers should be given heat controlarticles in high temperature season.
第五篇:专业英语
http://zaixianfanyi.com/google.php#hj
194页:了解什么归入类别嵌入计算,它足以说明什么不是嵌入式设备的要求。嵌入的设备的寿命非常不同于通用机器的3 年的逐渐过时循环。有些设备是几乎一次性的:平均日本celluar电话在少于一年被替换。在oppsite极端,基础建设的设备例如电话交换机在30年的日程表贬值。这些寿命差异产生具体的影响,可升级性和向后兼容性。少量嵌入设备有升级要求。例如,积极汽车热衷者更改自己的车里的芯片,但是这些通常是只读光盘,不是处理器。大多数消费者项将被替换,不会升级。
Backward compatibility is seldom an embedded requirement,as software does not migrate from one device to another.An interesting exception is game consoles:to maintain compatibility,later console chips must be capable of being exactly as fast as the early versions despite changes in underlying process technology.In consoles,backward compatible is often implemented by putting a complete copy of the previous-generation console in one small corner of the next-generation die.Bacause many embedded designs need not be backward compatible with previous implementations,designers are free to switch designs with each product generation.Consequently,there is less emphasis on the distinction between architecture and implementation.If a new version of a chip is slightly incompatible but much better than its predecessors,designers may still be willing to use it.因为软件并不从一个设备迁移到另一个,向后兼容性很少是嵌入式的要求,一个有趣的例外是游戏控制台:要维护兼容性,尽管最新控制台芯片在基础工艺技术上有所改变,但是它一定是可胜任的是象早版本一样快速地确切。往往通过将上一代控制台的完整副本放在一个小角落里的下一代模向后兼容。因为许多嵌入式的设计需要,不能与以前实现向后的兼容,设计师可以自由切换的每一代产品的设计。因此,有少强调体系结构与实施之间的区别。如果稍有不兼容,但比其前任的芯片的新版本,设计师仍可能愿意使用它。