有關(guān)單片機(jī)外文翻譯---微機(jī)發(fā)展簡(jiǎn)史

1、<p>　　畢 業(yè) 設(shè) 計(jì)（論 文）外 文 參 考 資 料 及 譯 文</p><p>　　譯文題目： Progress in Computers </p><p>　　微機(jī)發(fā)展簡(jiǎn)史 </p><p>　　學(xué)生姓名： 學(xué)　　號(hào)： </p&g

2、t;<p>　　?！　I(yè)： </p><p>　　所在學(xué)院： </p><p>　　指導(dǎo)教師： </p><p>　　職　　稱：

3、 </p><p>　　2012年 2 月 26 日</p><p><b>　　說明：</b></p><p>　　要求學(xué)生結(jié)合畢業(yè)設(shè)計(jì)（論文）課題參閱一篇以上的外文資料，并翻譯至少一萬印刷符（或譯出3千漢字）以上的譯文。譯文原則上要求打?。ㄈ缡謱懀宦捎?00字方格稿紙書寫），連同學(xué)

4、校提供的統(tǒng)一封面及英文原文裝訂，于畢業(yè)設(shè)計(jì)（論文）工作開始后2周內(nèi)完成，作為成績(jī)考核的一部分。</p><p>　　Progress in Computers</p><p>　　Prestige Lecture delivered to IEE, Cambridge, on 5 February 2004</p><p>　　Maurice Wilkes</

5、p><p>　　Computer Laboratory</p><p>　　University of Cambridge</p><p>　　The first stored program computers began to work around 1950. The one we built in Cambridge, the EDSAC was first u

6、sed in the summer of 1949.</p><p>　　These early experimental computers were built by people like myself with varying backgrounds. We all had extensive experience in electronic engineering and were confident

7、that that experience would stand us in good stead. This proved true, although we had some new things to learn. The most important of these was that transients must be treated correctly; what would cause a harmless flash

8、on the screen of a television set could lead to a serious error in a computer.</p><p>　　As far as computing circuits were concerned, we found ourselves with an embarass de richess. For example, we could use

9、vacuum tube diodes for gates as we did in the EDSAC or pentodes with control signals on both grids, a system widely used elsewhere. This sort of choice persisted and the term families of logic came into use. Those who ha

10、ve worked in the computer field will remember TTL, ECL and CMOS. Of these, CMOS has now become dominant.</p><p>　　In those early years, the IEE was still dominated by power engineering and we had to fight a

11、number of major battles in order to get radio engineering along with the rapidly developing subject of electronics.dubbed in the IEE light current electrical engineering.properly recognised as an activity in its own righ

12、t. I remember that we had some difficulty in organising a conference because the power engineers’ ways of doing things were not our ways. A minor source of irritation was that all IEE pub</p><p>　　Consolidat

13、ion in the 1960s </p><p>　　By the late 50s or early 1960s, the heroic pioneering stage was over and the computer field was starting up in real earnest. The number of computers in the world had increased and

14、they were much more reliable than the very early ones . To those years we can ascribe the first steps in high level languages and the first operating systems. Experimental time-sharing was beginning, and ultimately compu

15、ter graphics was to come along.</p><p>　　Above all, transistors began to replace vacuum tubes. This change presented a formidable challenge to the engineers of the day. They had to forget what they knew abou

16、t circuits and start again. It can only be said that they measured up superbly well to the challenge and that the change could not have gone more smoothly. </p><p>　　Soon it was found possible to put more th

17、an one transistor on the same bit of silicon, and this was the beginning of integrated circuits. As time went on, a sufficient level of integration was reached for one chip to accommodate enough transistors for a small n

18、umber of gates or flip flops. This led to a range of chips known as the 7400 series. The gates and flip flops were independent of one another and each had its own pins. They could be connected by off-chip wiring to make

19、a computer or anyth</p><p>　　These chips made a new kind of computer possible. It was called a minicomputer. It was something less that a mainframe, but still very powerful, and much more affordable. Instead

20、 of having one expensive mainframe for the whole organisation, a business or a university was able to have a minicomputer for each major department.</p><p>　　Before long minicomputers began to spread and bec

21、ome more powerful. The world was hungry for computing power and it had been very frustrating for industry not to be able to supply it on the scale required and at a reasonable cost. Minicomputers transformed the situatio

22、n.</p><p>　　The fall in the cost of computing did not start with the minicomputer; it had always been that way. This was what I meant when I referred in my abstract to inflation in the computer industry ‘goi

23、ng the other way’. As time goes on people get more for their money, not less. </p><p>　　Research in Computer Hardware. </p><p>　　The time that I am describing was a wonderful one for research in

24、 computer hardware. The user of the 7400 series could work at the gate and flip-flop level and yet the overall level of integration was sufficient to give a degree of reliability far above that of discreet transistors. T

25、he researcher, in a university or elsewhere, could build any digital device that a fertile imagination could conjure up. In the Computer Laboratory we built the Cambridge CAP, a full-scale minicomputer with fancy ca</

26、p><p>　　The 7400 series was still going strong in the mid 1970s and was used for the Cambridge Ring, a pioneering wide-band local area network. Publication of the design study for the Ring came just before the

27、announcement of the Ethernet. Until these two systems appeared, users had mostly been content with teletype-based local area networks. </p><p>　　Rings need high reliability because, as the pulses go repeated

28、ly round the ring, they must be continually amplified and regenerated. It was the high reliability provided by the 7400 series of chips that gave us the courage needed to embark on the project for the Cambridge Ring. <

29、;/p><p>　　The RISC Movement and Its Aftermath </p><p>　　Early computers had simple instruction sets. As time went on designers of commercially available machines added additional features which the

30、y thought would improve performance. Few comparative measurements were done and on the whole the choice of features depended upon the designer’s intuition.</p><p>　　In 1980, the RISC movement that was to cha

31、nge all this broke on the world. The movement opened with a paper by Patterson and Ditzel entitled The Case for the Reduced Instructions Set Computer.</p><p>　　Apart from leading to a striking acronym, this

32、title conveys little of the insights into instruction set design which went with the RISC movement, in particular the way it facilitated pipelining, a system whereby several instructions may be in different stages of exe

33、cution within the processor at the same time. Pipelining was not new, but it was new for small computers </p><p>　　The RISC movement benefited greatly from methods which had recently become available for est

34、imating the performance to be expected from a computer design without actually implementing it. I refer to the use of a powerful existing computer to simulate the new design. By the use of simulation, RISC advocates were

35、 able to predict with some confidence that a good RISC design would be able to out-perform the best conventional computers using the same circuit technology. This prediction was ultimately</p><p>　　Simulatio

36、n made rapid progress and soon came into universal use by computer designers. In consequence, computer design has become more of a science and less of an art. Today, designers expect to have a roomful of, computers avail

37、able to do their simulations, not just one. They refer to such a roomful by the attractive name of computer farm. </p><p>　　The x86 Instruction Set </p><p>　　Little is now heard of pre-RISC inst

38、ruction sets with one major exception, namely that of the Intel 8086 and its progeny, collectively referred to as x86. This has become the dominant instruction set and the RISC instruction sets that originally had a cons

39、iderable measure of success are having to put up a hard fight for survival.</p><p>　　This dominance of x86 disappoints people like myself who come from the research wings.both academic and industrial.of the

40、computer field. No doubt, business considerations have a lot to do with the survival of x86, but there are other reasons as well. However much we research oriented people would like to think otherwise. high level languag

41、es have not yet eliminated the use of machine code altogether. We need to keep reminding ourselves that there is much to be said for strict binary compatibili</p><p>　　There is an interesting sting in the ta

42、il of this apparently easy triumph of the x86 instruction set. It proved impossible to match the steadily increasing speed of RISC processors by direct implementation of the x86 instruction set as had been done in the pa

43、st. Instead, designers took a leaf out of the RISC book; although it is not obvious, on the surface, a modern x86 processor chip contains hidden within it a RISC-style processor with its own internal RISC coding. The inc

44、oming x86 code is, af</p><p>　　In this summing up of the RISC movement, I rely heavily on the latest edition of Hennessy and Patterson’s books on computer design as my supporting authority; see in particular

45、 Computer Architecture, third edition, 2003, pp 146, 151-4, 157-8. </p><p>　　The IA-64 instruction set. </p><p>　　Some time ago, Intel and Hewlett-Packard introduced the IA-64 instruction set. T

46、his was primarily intended to meet a generally recognised need for a 64 bit address space. In this, it followed the lead of the designers of the MIPS R4000 and Alpha. However one would have thought that Intel would have

47、stressed compatibility with the x86; the puzzle is that they did the exact opposite. </p><p>　　Moreover, built into the design of IA-64 is a feature known as predication which makes it incompatible in a majo

48、r way with all other instruction sets. In particular, it needs 6 extra bits with each instruction. This upsets the traditional balance between instruction word length and information content, and it changes significantly

49、 the brief of the compiler writer. </p><p>　　In spite of having an entirely new instruction set, Intel made the puzzling claim that chips based on IA-64 would be compatible with earlier x86 chips. It was har

50、d to see exactly what was meant.</p><p>　　Chips for the latest IA-64 processor, namely, the Itanium, appear to have special hardware for compatibility. Even so, x86 code runs very slowly.</p><p>

51、;　　Because of the above complications, implementation of IA-64 requires a larger chip than is required for more conventional instruction sets. This in turn implies a higher cost. Such at any rate, is the received wisdom,

52、 and, as a general principle, it was repeated as such by Gordon Moore when he visited Cambridge recently to open the Betty and Gordon Moore Library. I have, however, heard it said that the matter appears differently from

53、 within Intel. This I do not understand. But I am very ready to</p><p>　　AMD have defined a 64 bit instruction set that is more compatible with x86 and they appear to be making headway with it. The chip is n

54、ot a particularly large one. Some people think that this is what Intel should have done. [Since the lecture was delivered, Intel have announced that they will market a range of chips essentially compatible with those off

55、ered by AMD.] </p><p>　　The Relentless Drive towards Smaller Transistors </p><p>　　The scale of integration continued to increase. This was achieved by shrinking the original transistors so that

56、 more could be put on a chip. Moreover, the laws of physics were on the side of the manufacturers. The transistors also got faster, simply by getting smaller. It was therefore possible to have, at the same time, both hig

57、h density and high speed. </p><p>　　There was a further advantage. Chips are made on discs of silicon, known as wafers. Each wafer has on it a large number of individual chips, which are processed together a

58、nd later separated. Since shrinkage makes it possible to get more chips on a wafer, the cost per chip goes down. </p><p>　　Falling unit cost was important to the industry because, if the latest chips are che

59、aper to make as well as faster, there is no reason to go on offering the old ones, at least not indefinitely. There can thus be one product for the entire market. </p><p>　　However, detailed cost calculation

60、s showed that, in order to maintain this advantage as shrinkage proceeded beyond a certain point, it would be necessary to move to larger wafers. The increase in the size of wafers was no small matter. Originally, wafers

61、 were one or two inches in diameter, and by 2000 they were as much as twelve inches. At first, it puzzled me that, when shrinkage presented so many other problems, the industry should make things harder for itself by goi

62、ng to larger wafers. I now</p><p>　　The degree of integration is measured by the feature size, which, for a given technology, is best defined as the half the distance between wires in the densest chips made

63、in that technology. At the present time, production of 90 nm chips is still building up</p><p>　　Suspension of Law </p><p>　　In March 1997, Gordon Moore was a guest speaker at the celebrations o

64、f the centenary of the discovery of the electron held at the Cavendish Laboratory. It was during the course of his lecture that I first heard the fact that you can have silicon chips that are both fast and low in cost de

65、scribed as a violation of Murphy’s law.or Sod’s law as it is usually called in the UK. Moore said that experience in other fields would lead you to expect to have to choose between speed and cost, or to compromi</p>

66、;<p>　　In a reference book available on the web, Murphy is identified as an engineer working on human acceleration tests for the US Air Force in 1949. However, we were perfectly familiar with the law in my student

67、 days, when we called it by a much more prosaic name than either of those mentioned above, namely, the Law of General Cussedness. We even had a mock examination question in which the law featured. It was the type of ques

68、tion in which the first part asks for a definition of some law or principl</p><p>　　The single-chip computer </p><p>　　At each shrinkage the number of chips was reduced and there were fewer wire

69、s going from one chip to another. This led to an additional increment in overall speed, since the transmission of signals from one chip to another takes a long time. </p><p>　　Eventually, shrinkage proceeded

70、 to the point at which the whole processor except for the caches could be put on one chip. This enabled a workstation to be built that out-performed the fastest minicomputer of the day, and the result was to kill the min

71、icomputer stone dead. As we all know, this had severe consequences for the computer industry and for the people working in it. </p><p>　　From the above time the high density CMOS silicon chip was Cock of the

72、 Roost. Shrinkage went on until millions of transistors could be put on a single chip and the speed went up in proportion. </p><p>　　Processor designers began to experiment with new architectural features de

73、signed to give extra speed. One very successful experiment concerned methods for predicting the way program branches would go. It was a surprise to me how successful this was. It led to a significant speeding up of progr

74、am execution and other forms of prediction followed</p><p>　　Equally surprising is what it has been found possible to put on a single chip computer by way of advanced features. For example, features that had

75、 been developed for the IBM Model 91.the giant computer at the top of the System 360 range.are now to be found on microcomputers </p><p>　　Murphy’s Law remained in a state of suspension. No longer did it mak

76、e sense to build experimental computers out of chips with a small scale of integration, such as that provided by the 7400 series. People who wanted to do hardware research at the circuit level had no option but to design

77、 chips and seek for ways to get them made. For a time, this was possible, if not easy </p><p>　　Unfortunately, there has since been a dramatic increase in the cost of making chips, mainly because of the incr

78、eased cost of making masks for lithography, a photographic process used in the manufacture of chips. It has, in consequence, again become very difficult to finance the making of research chips, and this is a currently ca

79、use for some concern. </p><p>　　The Semiconductor Road Map </p><p>　　The extensive research and development work underlying the above advances has been made possible by a remarkable cooperative

80、effort on the part of the international semiconductor industry.</p><p>　　At one time US monopoly laws would probably have made it illegal for US companies to participate in such an effort. However about 1980

81、 significant and far reaching changes took place in the laws. The concept of pre-competitive research was introduced. Companies can now collaborate at the pre-competitive stage and later go on to develop products of thei

82、r own in the regular competitive manner. </p><p>　　The agent by which the pre-competitive research in the semi-conductor industry is managed is known as the Semiconductor Industry Association (SIA). This has

83、 been active as a US organisation since 1992 and it became international in 1998. Membership is open to any organisation that can contribute to the research effort. </p><p>　　Every two years SIA produces a n

84、ew version of a document known as the International Technological Roadmap for Semiconductors (ITRS), with an update in the intermediate years. The first volume bearing the title ‘Roadmap’ was issued in 1994 but two repor

85、ts, written in 1992 and distributed in 1993, are regarded as the true beginning of the series. </p><p>　　Successive roadmaps aim at providing the best available industrial consensus on the way that the indus

86、try should move forward. They set out in great detail.over a 15 year horizon. the targets that must be achieved if the number of components on a chip is to be doubled every eighteen months.that is, if Moore’s law is to b

87、e maintained.-and if the cost per chip is to fall.</p><p>　　In the case of some items, the way ahead is clear. In others, manufacturing problems are foreseen and solutions to them are known, although not yet

88、 fully worked out; these areas are coloured yellow in the tables. Areas for which problems are foreseen, but for which no manufacturable solutions are known, are coloured red. Red areas are referred to as Red Brick Walls

89、.</p><p>　　The targets set out in the Roadmaps have proved realistic as well as challenging, and the progress of the industry as a whole has followed the Roadmaps closely. This is a remarkable achievement an

90、d it may be said that the merits of cooperation and competition have been combined in an admirable manner.</p><p>　　It is to be noted that the major strategic decisions affecting the progress of the industry

91、 have been taken at the pre-competitive level in relative openness, rather than behind closed doors. These include the progression to larger wafers. </p><p>　　By 1995, I had begun to wonder exactly what woul

92、d happen when the inevitable point was reached at which it became impossible to make transistors any smaller. My enquiries led me to visit ARPA headquarters in Washington DC, where I was given a copy of the recently prod

93、uced Roadmap for 1994. This made it plain that serious problems would arise when a feature size of 100 nm was reached, an event projected to happen in 2007, with 70 nm following in 2010. The year for which the coming of

94、100 nm (or r</p><p>　　I presented the above information from the 1994 Roadmap, along with such other information that I could obtain, in a lecture to the IEE in London, entitled The CMOS end-point and relate

95、d topics in Computing and delivered on 8 February 1996.</p><p>　　The idea that I then had was that the end would be a direct consequence of the number of electrons available to represent a one being reduced

96、from thousands to a few hundred. At this point statistical fluctuations would become troublesome, and thereafter the circuits would either fail to work, or if they did work would not be any faster. In fact the physical l

97、imitations that are now beginning to make themselves felt do not arise through shortage of electrons, but because the insulating layers on</p><p>　　There are many problems facing the chip manufacturer other

98、than those that arise from fundamental physics, especially problems with lithography. In an update to the 2001 Roadmap published in 2002, it was stated that the continuation of progress at present rate will be at risk as

99、 we approach 2005 when the roadmap projects that progress will stall without research break-throughs in most technical areas “. This was the most specific statement about the Red Brick Wall, that had so far come from the