Impact of very-large-scale integration(v.l.s.i.) on systems and people

O.G. Folberth

Indexing term: Large-scale integration

Abstract: The impact of semiconductor technology on systems and on people is substantial, and increaseswith further increasing scales of integration. This is mainly the result of further cost reductions and there-fore of a growing penetration of highly integrated silicon chips into a wide variety of applications. In the firstpart of the paper, the impact of v.l.s.i. on systems will be discussed, dealing especially with the followingtopics: benefits from integration, differentiated cost reductions, new applications, regular arrays and randomlogic, performance implications, system size, and interface problems. The second part of the paper deals withpeople-oriented topics: dimensions of knowledge, 'remote engineering', simulation and modelling, changingcareers, numeracy, productivity impact, and technology: no end in itself.

1 Introduction

Integrated circuit technology is still progressing rapidly.Large scale integration is here to stay, and the age of verylarge scale integration is in sight (Fig. 1). For the future,we can therefore expect a further decrease in the cost oftransistor functions and a further penetration of highlyintegrated silicon chips into a wide variety of applications.Traditional as well as new and nontraditional applicationswill profit from this evolution.

In the paper the impact of v.l.s.i. on future systems andon people will be assessed. Part of this impact is clearlyvisible and well recognisable; other parts are of a morespeculative nature. The respective observations are arrangedunder 14 headings. The topics on which there is a good

1M

80

Fig. 1 Approximate component count for complex integratedcircuits against year of introduction(reproduced from Technical Digest of the International Electron-Device Meeting, Washington 1975,p. 11,contribution by G.E.Moore)o Bipolar logicA Bipolar arraysa M.O.S. logic0 M.O.S. arrays

Paper T214C, first received 13th December 1977 and in revisedform 10th April 1978Prof. Folberth is with IBM Deutschland GmbH, Entwicklung undForschung, D-703 Boblingen, Schonaicher Str 220, West Germany

measure of agreement are considered first, followed by themore speculative ones.

2 Impact on systems

2.1 Benefits from integration

The breathtaking progress in microelectronics during thepast two decades was characterised to a large extent by asynergy between semiconductor technology and data pro-cessing. Advances in semiconductors resulted in thedevelopment of computers with ever better cost/perfor-mance ratio thereby making new applications practical andreaching a wider market which, in turn, stimulatedincreased research and development efforts in the field ofsemiconductors, and so on.1 In this respect, the method ofthe integration of more and more components on smallsilicon chips — or, in other words, the increase of the levelof integration from s.si. (small-scale integration) throughm.s.i. (medium-scale integration), and l.s.i. (large-scaleintegration), up to v.l.s.i. (very large scale integration) —proved itself particularly effective. With the increase inthe level of integration, essentially all characteristic par-ameters of electronic systems have been improvedsimultaneously. The system performance has been in-creased, the power dissipation per circuit has been reduced,the computing speed has been increased, the reliability hasbeen improved, and — last but not least — cost and priceshave been reduced.

2.2 Differentiated cost reductions

Cost reductions for transistor functions, dramatic as theywere, did not fully penetrate to the system level, mainlydue to two reasons:

(a) Systems are composed of a variety of subsystems,not all of which profit from l.s.i. to the same extent. Someunits such as input/output units and power supply unitshave not been substantially affected by l.s.i. yet and respec-tive cost reductions have been much more moderatecompared to those much greater reductions for logic,memory and control.2 Therefore, the total cost reductionof hardware was somewhere in-between.

(b) Transistor functions did not become cheap per se,but only if used in large quantities. This trend stimulatedthe use of more functions and the design of sophisticatedequipment. Only some of these functions are used for the

COMPUTERS AND DIGITAL TECHNIQUES, AUGUST 1978, Vol. l.No. 3 69

0140-1335/78/214C-0069 $1-50/0

job proper, the — often greater — remainder are added foruser convenience in supporting jobs such as error correction,testing aids, diagnosis, self-repair, etc. Moreover, the, nowabundantly available, cheap amplification (transistorfunctions) is, in the main, not used as straightforwardamplification but traded in favour of more precision,stabilisation, noise suppression, signal refreshing andrestoring, etc. Many papers given at ESSCIRC conferencesdescribe such approaches.

With v.l.s.i., the trend towards even more sophisticatedhardware with overall moderate price reductions willcontinue.

2.3 New applications

Cheaper components stimulate new applications (Fig. 2).Most of these new applications did not come about due toa grandiose plan: they were essentially the result of emerg-ing technological capabilities. In other words the progresswas primarily technology-driven, while the 'planning' ofnew applications usually made little impact. Each newapplication has its own price/performance threshold, fromwhich a profitable market emerges. When the technologicalprogress hits this threshold, usually a booming situationarises. It is rare for such a point in time to be predictedcorrectly.

The market potential for hand-held calculators wasobvious; but, ten years ago, even the most sophisticated'planning' would not have yielded the production andsale of a single unit of this type and would not have pro-duced the slightest tinge of a new market. There was, atthat time, just no adequate technology available for thiskind of application. A few years later, with P-m.o.s. l.s.i.and GaAsP l.e.d.s fully developed, calculator chips anddisplays became available in large quantities at low cost.Therefore, this application suddenly became an explosivelyexpanding market. I am sure that the actual sales figuresin this now slowly saturating market differ very much fromany planning figures generated by anyone at any time inthe game.

Similar comments can be made for other applications:neither the breakthrough of the operational amplifier in thelate 1960s nor the presently occurring skyrocketing micro-processor boom was predicted years in advance. Thesituation suddenly ignited when the technology was ripe forsuch applications, much to the surprise of many pro-fessional business planners.

discrete1000-

100 -

* micro -t< processor

/electr.*^ wristwatch

2.4 Regular arrays and random logic

Progress in l.s.i. was, and is, much faster in modular arrays(particularly memories) than in random logic. Systems ofall sizes profit from l.s.i. memories. The costs of memorybits dropped across the whole product line. Progress inlogic, on the other hand, was (and still is) held up byproblems such as design complexity, testing, partitioning,pin limitation, etc. The problems mentioned plague largesystems more than $mall systems, where they have beenovercome, at least partly, by the introduction of techniquessuch as bit slicing, multiplexing, bidirectional switching, etc.Furthermore, the extensive use of array structures,wherever possible (r.o.m.s, p.r.o.m.s, p.l.a.s and the like),contributed considerably to the successful introduction ofl.s.i., especially where ultrahigh performance is not a keyissue. V.L.S.I. will make large 'small systems' viable!

2.5 Performance implications

As already mentioned l.s.i., and even more so vJ.s.i., provedto be very instrumental in lowering the cost of hardware.Progress could be measured in orders of magnitude duringthe last two decades. However, l.s.i. and vJ.s.i. also havean impact on the performance of hardware.

This shows itself, essentially, in reduced capacitances ofminiaturised hardware (and the thereby reduced RC times)combined with reduced wiring lengths (reduced signalpropagation delays) which contribute to the increasedperformance of the compact, highly integrated, hardware(in comparison to the less dense hardware of s.s.i. andm.s.i.). These performance improvements, however, aremuch smaller than the previously described density andcost improvements. They are measured by factors of 2 or3 and not in orders of magnitude. In addition, progress isslowed down by the following basic problem: thecommonly applied design principles derived from traditionalswitching theory are largely irrelevant for digital designs invJ.s.i. This traditional switching theory concerns itselfmainly with sequences of digital operations distributed intime, largely disregarding the spatial arrangement of thecircuits. The performance of v.l.s.i. chips, however, dependsstrongly on the spatial placement of the functions on thechip, since the interconnections occupy a large part of thespace on the chip and consume a significant amount of theswitching time. Therefore, future switching theories

microcircuits

breadth of knowledge

0011955 1960 1965 1970 1975 1980

Fig. 2 Lower cost per function stimulates new products

Fig. 3 Dimensions of knowledge

These curves suggest how knowledge intensifies and broadens aselectronics progresses to microcircuits. Two things speed up theinnovation process (17 yrs. for transistors against 40 yrs. for tubes).First, knowledge intensifies and broadens among specialists inmaterials, devices, circuits, and systems. Second, these specialistsbegin to share common knowledge as symbolised by the overlappingof the specialist areas on the curves.

70 COMPUTERS AND DIGITAL TECHNIQUES, AUGUST 1978, Vol. 1, No. 3

applicable to v.l.s j . will have to include principles akin totopology or crystallography.8 Such theories are still in theirinfancy and their impact on practical system design isminimal, as yet.

Furthermore, as a general rule, the higher the circuitperformance, the higher is the power dissipation per circuit.Therefore, the integration density of high-performancesystems is severely limited by heat dissipation and coolingproblems. Thus, in their present configuration, largesystems are largely composed of m.s.i. circuits.

Higher integration densities of high-speed circuits willonly become feasible if circuit technologies with a lowerspeed-power product (at the high-speed range) becomeavailable. There is progress in this field, but at a relativelyslow pace. Consequently, l.s.i. penetrates the logic of largesystems slowly, its major impact still ahead of us(Table 1).*

Table 1: Large digital systems

Assumptions:— circuit technology with speed-power-product: 1 pJ— maximum power dissipation per chip: 1 W— logic delays per machine cycle-: 10

Consequence:maximum number of logic decisions per son a chip: 10' '(independent of the integration-level I)

Status:fastest computers built so far:«» 10'3 logic decisions per s

Problem:partitioning of logic into approx. 100 chips

Result:large (fast) systems are still mainly based onm.s.i. -logic

Wanted:a circuit-technology withs.p.p. «0-01 pJ \ , ,. . , ; / o r less!at a delay of 1 nsj

2.6 System size

At present, the number of gates of a data processing systemis a good indicator for its size: 'maxiprocessors' have manymore gates than miniprocessors and these in turn, morethan microprocessors. With the advent of v.l.s.i. it is verylikely that these differences will become less and less signifi-cant (apart from the still important performance differ-ences; maxis will continue to be faster than micros) and themain differences will lie in the input/output and softwareareas. Large systems will provide more sophisticated inputand output devices and will provide convenient, easy touse, software, while mini- and micro-systems cannot affordto offer all this comfort. It is to be expected that thewhole palette of systems from the ultrafast large instal-lations to the very small ones will still find their customersin the future. Considering the total job, large installationsare often more economical than small ones: large instal-lations with sophisticated software require relatively littlehuman effort for their operation, while with smallinstallations more functions must be performed by(expensive) human labour.9

2.7 In terface problems

Through v.l.s.i. such old dreams as the 'computer-on-a-chip'and the 'radio-on-a-chip' will become reality. But also other

DILL, F.R.: private communication

highly integrated units, performing functions which so farwere the domain of composite systems or subsystems,emerge in rapid progression. Wherever such items can beused as stand-alone units or as attachments to well intro-duced equipment (such areas are e.g., watches, calculators,hobby computers, video games, measurement and com-munication systems) a speedy introduction can beenvisaged.

Many other applications, however, will be conqueredmore slowly, the main stumbling block being the interfaceproblem. In many cases such as appliances, automobiles,and the medical and health industry good, reliable andcheap sensing and activating devices are not always avail-able. The cost of a 10$ microprocessor is negligible, if thecost of the total installation is in the 4-digit range. But themicroprocessor will not be sold (in spite of its cheapness),if the total installation is too expensive. Progress in thesefields might be slower than some optimists may assume.This is mainly due to the very rugged and strange environ-ments of the envisioned application areas and the extremelysevere boundary conditions imposed (e.g., 'housewife-proof). It will be difficult to persuade a regular housewifeto operate a microprocessor, controlling the boiling of aliquid in a pot on a hotplate, if for an efficient operationshe has to key-in such data as the volume of the liquid, thesize and shape of the pot, the reading on the barometer, thesurface condition of the plate and of the bottom of the potand other data. This example might be an extreme, but Ihope it illustrates my point.

There is no doubt, however, that progress will come inthese fields too, but it is dependent on much more (andmore complex) factors than only on the progress in vJ.s.i.!

3 Impact on people

In the second half of this paper I will deal with the impactof v.l.sj. on people. In this respect, I will distinguishbetween the impact on those of us who are involved in thedevelopment and manufacturing of v.l.s.i. (i.e., thescientists, engineers, and technicians) and the 'rest of thehumanity' who are essentially in the user role. While Ibelieve that the impact on the first group is clearly compre-hensible and fairly well understood, our knowledge aboutthe impact on the second group contains considerableuncertainty. Therefore, my statements about the firstare fairly well founded, while my statements about thesecond group will be highly speculative.

3.1 Dimensions of knowledge

The advent of l.s.i. and vJ.s.i. changed the professionalambience and career pattern of those involved in theresearch, development, manufacturing, and application ofmicroelectronic devices in a very dramatic way. Suchchanges were already observable in the early 1960s in theinfancy age of i.cs. This is best illustrated in a picturewhich I found in an older publication3 by the late JackMorton, at that time vice-president of the Bell TelephoneLaboratories (Fig. 3). It shows three trends:

(i) The time to develop the knowledge has shrunk; wehave to acquire more new knowledge in shorter time spans.

(ii)The intensity of the knowledge increased; moreknowledge is required to do the job.

(iii) The breadth of the knowledge which each personneeds in order to do his job increased, too. The classicaljobs of material specialist, device physicist, circuit engineer,

COMPUTERS AND DIGITAL TECHNIQUES, AUGUST 1978, Vol. 1, No. 3 71

and system designer merged into each other. This trend isfurther emphasised by the application of superintegration(or the merging principle4) for l.s.i. and v.l.s.i. With super-integration even the last boundary still detectable inJack Morton's diagram, namely that between devices andcircuits, became blurred or vanished altogether!

Consequently, in the vJ.s.i. age, the engineering jobbecomes more demanding and more difficult, and con-tinuously requires the acquisition of new knowledge andskill. Our educational system has not yet fully respondedto this changing demand. Especially, the engineeringeducation is still too much departmentalised and thebreadth of knowledge of our graduates is often toonarrow.5

3.2 'Remote engineering'

With the introduction of highly integrated components, thework of the circuit engineer changed substantially: bread-boarding (one of the major laboratory tasks of a circuitengineer in the old days of discrete componentry) hasbeen almost completely replaced by simulation and model-ling. Now the engineer's main tool is the computerkeyboard and no longer the soldering iron. Every error inhis assumptions, groundrules, entry data, models etc. hasa much more devastating, costly and time-consuming effectthan in the old days of breadboard experimenting. At thattime you could change a circuit easily by replacing, say,a 1 kI2 resistor with a 2 k£2 resistor or by inserting anothertube or transistor into a socket. You could make thischange on one prototype within a few minutes at the costof a few dollars. Now, if you have to change some circuitparameters in a vJ.s.i. chip, you may find that you have todo it on many prototypes (at least on one wafer lot), itcould take as long as many months before it reaches thetest (this means, before you know for sure, whether thedeficiency was corrected by the change, and no newdeficiency was introduced) and it could cost you (or yourcompany!) a 4 or 5 digit amount of dollars.

Therefore, the preparatory work must now be donemuch more carefully and numerous iterations are necessarybefore the pilot line work should be started. Once thedesign is frozen and the masks are made, any changesrequired from then on will have a great impact on schedulesand costs. The famous 'trial and error' method should berestricted to the simulation and modelling phase, as muchas possible.

In this new working arrangement, the circuit engineercan very seldom see or touch his product. For most of thetime he will work remotely from his 'baby' on a keyboardand a screen, and will 'see' his product only in thick paperstacks of computer printouts or in jittering symbols on ascreen. This 'remote engineering' creates a major psycho-logical problem: the experience of success (or failure!) is nolonger directly coupled with the achievement but comesonly in a very filtered and coded form at a much later stage.Therefore, its stimulating effect is weak and out of phase.

It remains to be seen how future generations of elec-tronic engineers will cope with this problem, for whichthey are essentially unprepared, when they start theiremployment.

3.3 Simulation and modelling

Modelling is vital for succeeding in v.l.s.i. But modelling isnot, and should not be, a goal in itself. It is 'only' a tool

(to be sure: a very significant one) in order to developappropriate hardware. Any simulation, therefore, is justa simulation and not the real thing! Very often, however,the preoccupation of engineers working on modelling andsimulation leads them to put too much emphasis on themodel as such, neglecting sometimes the underlyingphysics. Consequently, models are often misapplied andinaccurate or invalid conclusions are drawn. One shouldalways bear in mind that each model — sophisticated as itmight be — is based on simplifications.

The rapid progress of miniaturisation made it necessaryto continually check the validity of old models and tointroduce refinements. Continually, new effects havebecome significant which have either been unknownpreviously or have been known, but were neglected asinsignificant at previous, less dense, integration levels.The introduction of the 'short channel effect' intom.o.s.f.e.t. models or the introduction of 'high injectionlevels' into bipolar models are examples of this kind.

This trend will definitely continue, and new refinementswill become necessary. In the final analysis, if unresolvabledifferences persist, the hardware is always right and themodel is wrong. Therefore, our marvellous computationaltools have to be applied with due responsibility and soundself-criticism. The quality of the results depends stronglyon the quality of the algorithm, input data and handling.A computer 'as such' is a stupid thing. The 'g.i.g.o. effect'(garbage in-garbage out) is an experience to which anengineering novice cannot be exposed too soon; a lesson hemust learn in order to avoid these pitfalls, in future.

3.4 Changing careers

The great success of modern microelectronics is based onsilicon technology, especially its latest offspring: v.s.l.i.This success relegated all searches for alternative tech-nologies to a lower priority class. This holds for theexploration of other materials such as Ge, GaAs, ternarycompounds, etc. as well as for the investigation of othersignal processing principles such as Parametrons, Gunn-effect logic, etc.

Silicon is presently the key material and probably thebest understood substance on earth. Its properties arealready explored in very much detail and new results anddata become available almost daily.

While many applied physicists are still working in thisfield, their work lost some of its significance and glamourcompared to a time 30 years ago, say around the discoverydate of the transistor. Now effects of second and thirdorder have to be explored, all basic physical problemshaving already been resolved. In other words, the presentwork of the physicist in microelectronics is predominantlyproject oriented (very applied) and not so much phenomenaoriented (basic) as in the old days. Therefore, the overallrole of the physicists and their contribution toward thefurther improvement of microelectronics is declining,regardless of the fact that there are still many physicalproblems, and good physicists are required e.g., forelectron-beam lithography, to name just one area of highimportance.

The role of the classical electronics engineer, moreover,is also declining. Especially with the advent of the micro-processor, numerous tasks which were previously tackledby the design of special chips (custom design) are nowsolved by programming.6 Consequently, the role of the

72 COMPUTERS AND DIGITAL TECHNIQUES, AUGUST 1978, Vol. 1, No. 3

software engineer is increasing, while the role of the hard-ware engineer (although still very important) will notincrease at the same pace.

Laboratory work will consist of an ever-increasingamount of data processing of the one or other sort.

4 Impact on society

My three concluding topics concern the impact of v.l.s.i.on society-at-large. V.L.S.I. will bring electronic gadgetsto almost every person and to almost every home. The long-range impact of this penetration is far from being com-pletely understood in every detail. So far only a blurredpattern has emerged and only vague conclusions can bedrawn.

4.1 Numeracy

The art of figuring and calculating is impacted by theabundance of cheap pocket calculators. Due to the rapidspread of these handy gadgets, basic arithmetic skills, oneof the major training objects in elementary schools, becomeless and less significant for everyday use. Therefore, theseskills will not be practised any more by large fractions ofour society, including scientifically and technically trainedpeople.

Is this good or is it bad? Maybe it is good and bad at thesame time. It is definitely bad from a traditional point ofview, since a very old and basic skill of our civilisationdisappears. But, on the other hand, the disappearance ofthe need to multiply or divide by heart or with pencil andpaper may free capacity in the human brain for other,more productive activities. But it just may! It could verywell be that with the disappearance of this skill to handlefigures, human behaviour may change in yet-unpredictableways. One subtle change of this kind seems observablealready, namely the growing weakness in 'numeracy'.

Numeracy is the art of assessing and handling orders ofmagnitude and of understanding their significance andfunctional relationship. In our age of the cheap calculator,numeracy becomes a vital skill: the pushing of just onewrong button on a calculator can render a result wrong bymany orders of magnitude up to the utmost extreme ofconverting it to its contrary (negative instead of positive,complement instead of true, reciprocal instead of direct,etc.). Only with a well developed sense for numeracy cansuch mistakes be detected and avoided. Therefore, it willbecome of greater importance to teach numeracy and toreduce the effort for routine-calculus training in our futureeducational system.

Numeracy is essential in order to keep track of themanipulations in a calculator or computer. Display figuresand computer printouts are meaningless per se (or evenworse: they can be misleading), if the entry data and/or thehandling contains errors. This may sound very trivial to anexpert, but violations against this basic rule are still veryfrequent and may increase with the spread of digital equip-ment into the less well trained populace, if no counter-actions by dedicated education become part of theelementary schooling system.

4.2 Productivity impact

V.L.S.I. will contribute to the further rationalisation oflabour to an extent which surpasses probably the effectof all past rationalisation efforts (the 'third industrialrevolution'). Greater output will be achievable with less

manpower, aggravating thereby the already grave un-employment situation in our society.7 Presently this is avery rnuch discussed subject among politicians, economists,union leaders, corporate managers, etc. It would beinappropriate, if here a new proposal would be added to themany proposals already made for the solution of this severeproblem. Some of these proposals might be feasible andviable, but only if they assure that the remaining work isdistributed over more people. This is only possible, if theaverage annual income increase of all wage and salaryearners is lower than the average annual productivityincrease. So far, the usual practice revealed a trend contraryto these recommendations.

4.3 Technology: not an end in itself

Our society has become increasingly sceptical with regardto the acceptance of new technological achievements. Theoverheated discussions about nuclear power plants arestriking examples. So far, reservations against new elec-tronic devices have not been that agitated. Most of theadverse arguments are rather indirect such as the increasingsuspicion against a more and more rationalised and com-puterised world, in the manner of Orwell's '1984'.

There is no doubt that with v.l.sj., and thereforecheaper gates, bytes, amplifiers etc., we will have a furtherpenetration of electronics into everyday life. Whether, inthe course of this evolution, the overall 'quality of life' willincrease or not is in its essence not a technical question.This is more a philosophical (sociological, political,pyschological.. .) problem. But, of course, there will be asubstantial feed-back to the technical world. Probably themost significant facet will be an increased overall conscious-ness about the fact that the technological side of theproblem is just one (of course very significant) issue amongothers. The alertness of the engineer with regard to thisoften forgotten or suppressed truism will have to bedeveloped. Both our educational system and our labourworld must be adjusted accordingly.

5 References

1 NOYCE, R.N.: 'From relays to MPUs', Computer, 1976, 9, (12),pp. 26-29

2 DENNIS, S.F., and SMITH, M.G.: 'LSI-implications for futuredesign and architecture', AFIPS Conference Proceedings, 1972,40, pp. 343-351

3 MORTON, J.A.: "The microelectronics dilemma', Int. Sci. &TechnoL, 1966,55, pp. 35-44

4 WARNER, R.M. Jun.: 'I2L: a happy merger', IEEE Spectrum,1976,13, (5), pp. 42-47

5 see for example: WALKER, G.M.: 'EEs feel impact of micro-processors', Electronics, 1977, 50, (15), pp. 95-102 and 'EEsappraise career trends for 1980s', ibid., 1977, 50, (16), pp. 87 -94

6 PETRITZ, R.L.: 'Emerging role and impact of the micro-processor', Digest of the IEEE International Solid State CircuitsConference 1976, pp. 50-51 and 'The pervasive microprocessor:trends and prospects', IEEE Spectrum, 1977, 13, (17), pp. 18-24

7 See for example: 'Ein Volkswagen fur fiinf Mark', Wirtschafts-woche, 10 June 1977, pp. 14-23

8 SUTHERLAND, I.E., and MEAD, C.A.: 'Microelectronics andcomputer science1, Sci. Am., 1977, 237,(3), pp. 210-228

9 GROSCH, H.: quoted in Output, 1977, 6, (10), p. 16

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