Top-Down Digital VLSI Design: From Architectures to Gate-Level Circuits and FPGAs

578 Pages·2014·21.07 MB·English

by  Hubert Kaeslin

Top-Down Digital
VLSI Design
Top-Down Digital
VLSI Design
From Architectures
to Gate-Level Circuits and FPGAs
Hubert Kaeslin
Microelectronics Design Center
Department of Information Technology and Electrical Engineering
ETH Zürich
Switzerland
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Kaeslin,Hubert,author.
Top-downdigitalVLSIdesign:fromarchitecturestogate-levelcircuitsandFPGAS/HubertKaeslin,
MicroelectronicsDesignCenter,Dept.ofInformationTechnologyandElectricalEngineering,
ETHZurich,Switzerland.
pagescm
ISBN978-0-12-800730-3
1. Digitalintegratedcircuits–Designandconstruction.2. Integratedcircuits–Verylargescale
integration–Designandconstruction.I.Title.
TK7874.65.K3362015
(cid:2)
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2014035133
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Preface
WHY THIS BOOK?
Designing integrated electronics has become a multidisciplinary enterprise that involves solving
problemsfromfieldsasdisparateas
• Hardwarearchitecture
(cid:129) Softwareengineering
(cid:129) Marketingandinvestment
(cid:129) Semiconductorphysics
(cid:129) Systemsengineeringandverification
(cid:129) Circuitdesign
(cid:129) Discretemathematics
(cid:129) Layoutdesign
(cid:129) Electronicdesignautomation
(cid:129) Hardwaretestequipmentandmeasurementtechniques
Covering all these subjects is clearly beyond the scope of this text and also beyond the author’s
proficiency. Yet, I have made an attempt to collect material from the above fields that I have found
to be relevant for making major design decisions and for carrying out the actual engineering work
whendevelopingVeryLargeScaleIntegration(VLSI)circuits.
Thepresentvolumecoversfront-enddesign,thatisallstepsrequiredtoturnasoftwaremodelintoa
gate-levelnetlistor,alternatively,intoa bitstream forconfiguringfield-programmablelogic devices.
Asecondvolumeonback-enddesignmayfollowatalaterdate.
Thetexthasbeenwrittenwithtwoaudiencesinmind.Asatextbook,itwantstointroduceengineering
studentstothebeautyandthechallengesofdigitalVLSIdesignwhilepreventingthemfromrepeating
mistakes that others have made before. Practising electronics engineersshould find it appealing as a
reference book because of the many tables, checklists, diagrams, and case studies intended to help
them not to overlook important action items and alternative options when planning to develop their
owncircuits.
Whatsetsthisbookapartfromothersinthefieldisitstop-downapproach.Beginningwithhardware
architectures,ratherthanwithsolid-statephysics,naturallyfollowsthenormalVLSIdesignflowand
makesthematerialmoreaccessibletoreaderswithabackgroundinsystemsengineering,information
technology,digitalsignalprocessing,ormanagement.
xv
xvi Preface
HIGHLIGHTS
(cid:129) Top-downapproach.
(cid:129) Systematicoverviewonarchitectureoptimizationtechniques.
(cid:129) Achapteronfield-programmablelogicdevices,theirtechnologiesandarchitectures.
(cid:129) KeyconceptsbehindbothVHDLandSystemVerilogwithouttoomanysyntacticaldetails.
(cid:129) Aprovennamingconventionforsignalsandvariables.
(cid:129) Introductiontoassertion-basedverification.
(cid:129) Conceptsforre-usablesimulationtestbenches.
(cid:129) EmphasisonsynchronousdesignandHDLcodeportability.
(cid:129) Comprehensivediscussionofclockingdisciplines.
(cid:129) Largelyself-contained(requiredpreviousknowledgesummarizedintwoappendices).
(cid:129) Emphasisonknowledgelikelytoremainusefulintheyearstocome.
(cid:129) Plentyofdetailedillustrations.
(cid:129) Checklists,hintsandwarningsforvarioussituations.
(cid:129) Aconceptproveninclassroomteachingandactualdesignprojects.
NOTES TO INSTRUCTORS
Overthepastdecade,thecapabilitiesofField-ProgrammableGateArrays(FPGA)havegrowntoapoint
where they compete with custom-fabricated ICs in many electronic designs, especially for products
marketedbysmallandmediumenterprises.
Beginning with the higher levels of abstraction enables instructors to focus on those topics that are
equallyrelevantirrespectiveofwhetheradesigneventuallygetsimplementedas“mask-programmed”
chiporfromcomponentsthatareconfiguredelectrically.Thatmaterialiscollectedinchapters1to6
of the book and best taught as part of a Bachelor program for maximum dissemination. No prior
introduction to semiconductor physics or devices is required. For audiences with little exposure to
digital logic and finite state machines, the material can always be complemented with appendices A
andB.
Chapter7istheonlyonetohaveaclearorientationtowardsmask-programmedcircuitsasclockingand
clockdistributionarelargelypre-definedinfield-programmablelogicdevices.Asopposedtothis,the
materialonsynchronizationinchapter8isequallyimportanttoFPGAusersandtopersonsspecializing
infull-orsemi-customdesign.
Probably the best way of preparingfor an engineeringcareer in the electronics and microelectronics
industry is to complete a design project where circuits are not just being modeled and simulated on
a computer butactually fabricated and tested. At ETH Zürich, students are given this opportunityas
partofathree-semestercoursegivenbytheauthorandhiscolleagues,seefigurebelow.The6thterm
covers front-end design. Building a circuit of modest size with an FPGA is practiced in a series of
exercises.Providedtheycomeupwith ameaningfulproposal,studentsthengetacceptedforamuch
moresubstantialprojectthatrunsinparallelwiththeirregularlecturesandexercisesduringthe7thterm.
Preface xvii
Typicallyworkinginteamsoftwo,studentsareexpectedtodevoteatleasthalfoftheirworkingtime
tothatproject.Followingtapeoutattheendoftheterm,chipfabricationviaanexternalmulti-project
waferserviceroughlytakesthreemonths.Circuitsamplesthengetsystematicallytestedbytheirvery
developersinthe8thandfinalterm.Needlesstosaythatstudentsacceptingthisofferfeelverymotivated
andthatindustryhighlyvaluesthepracticalexperienceofgraduatesformedinthisway.
Mostchaptersin thisbookcomewith studentproblems.Someofthemexposeideasleftasidein the
maintextforthesakeofconciseness.Problemsaregradedasafunctionoftheeffortrequiredtosolve
them.
∗ Afewthoughtsleadtoabriefanswer.
∗∗ Detailsneedtobeworkedout,countbetween20minand90min.
∗∗∗ Asmallengineeringproject,multiplesolutionsmayexist.AccesstoEDAandothercomputer
toolsmayhelp.
Solutionsandpresentationslidesareavailabletoinstructorswhoregisterwiththepublisherfromthe
book’scompanionwebsitehttp://booksite.elsevier.com/9780128007303.
x
v
Syllabus of ETH Zurich in Microelectronics Design Center Integrated Systems Laboratory iii
Digital VLSI Design and Test Prof. Hubert Kaeslin Dr. Norbert Felber
P
r
Degree Bachelor Master ef
a
c
e
Calendar Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May
6th term 7th term 8th term
✰ ✰ ✰
Specials student projects low pwr research industry
Lectures VLSI I: VLSI II: VLSI III: Fabrication and
Architectures of VLSI Circuits Design of VLSI Circuits Testing of VLSI Circuits
Key topics top ✦ Clocking & synchronization ✦ VLSI testing
✦ Back-end design ✦ CMOS fabrication
✦ Architecture design
✦ Technology outlook
✦ HW Description Languages ✦ Parasitic effects
✦ Functional verification ✦ VLSI economics down
Exercises From VHDL to FPGA IC design through to final layout Testing of fabricated ICs
Testing
Student project
(optional) Speci- Modeling Circuit design
fication
Fabrication on MPWs
Milestones
accepted software overall synthesis verified verified test vectors test report
proposal model architecture model netlist layout,
project report
hk 16.1.2014
Acknowledgments
Thistextcollectstheinsightandtheexperiencethatmanypersonshaveaccumulatedovermorethan
twenty years. WhileI was fortunateenoughto author the book,I am indebted to all those who have
beenwillingtosharetheirexpertisewithme.
My thanks thus go to many past and present colleagues of mine including Christoph Balmer,
DavidBellasi,Prof.AndreasBurg,Dr.FelixBürgin,Dr.NorbertFelber,Prof.em.WolfgangFichtner,
MichaelGautschi,Dr.PierreGreisen,Dr.FrankGürkaynak,ChristophKeller,Prof.MathieuLuisier,
Dr.PatrickMächler,BeatMuheim,MichaelMühlberghuber,MichaelSchaffner,Prof.ChristophStuder,
Prof.JürgenWassner,Dr.MarkusWenk,Prof.PaulZbinden,andDr.RetoZimmermann.Aslong-time
VHDL users, our staff and me are grateful to Dr. Christoph Sühnel who made us become fluent in
SystemVerilog with as few detours and misunderstandings as possible. Most of these experts have
contributed examples, have reviewed parts of my manuscript, or have otherwise helped improve its
quality.Still,theonlypersontoblameforallerrorsandothershortcomingsthathaveremainedinthe
textisme.
Next,IwouldliketoextendmysincerethankstoallstudentswhohavefollowedourcoursesonDigital
VLSIDesignandTest.Notonlytheircommentsandquestions,butalsoresultsanddatafrommanyof
theirprojectshavefoundtheirwayintothistext.SebastianAxmanndeservesspecialcreditforhelping
withthesolutionsonavoluntarybasis.
Giving students the opportunity to design microchips, to have them fabricated, and to test physical
samplesisaratheronerousundertakingthatwouldclearlyhavebeenimpossiblewithoutthecontinuous
fundingbyETHZürich.Letmeexpressourgratitudeforthatonbehalfofallourgraduates.
In cooperationwith ChristophWickiand his IT supportteam, thestaff of thelocal Microelectronics
DesignCenterdoesasuperbjobinsettingupandmaintainingtheEDAinfrastructureandtheservices
indispensableforVLSIdesigninspiteofthefrequentlandslidescausedbyrapidtechnologicalevolution
and by unforeseeable business changes. I am particularly grateful to them for occasionally filling all
sortsofgapsinmytechnicalknowledgewithoutmakingmefeeltoobadlyaboutit.
IamfurtherindebtedtoToddGreen,NateMcFadden,PoulouseJoseph,andmanymoremembersof
thestaff atMorganKaufmannPublishersfortheir supportwith turningmyLaTeXmanuscriptintoa
printedbook.Finally,Iwouldliketothankallpersonsandorganizationswhohavetakentheirtimeto
answermyreprintrequestsandwhohavegrantedmetherighttoreproduceillustrationsoftheirs.
xix
CHAPTER
1
INTRODUCTION TO
MICROELECTRONICS
1.1 ECONOMIC IMPACT
Letusbeginbyrelatingtheworldwidesalesofsemiconductorproductstotheworld’sgrossdomestic
product(GDP)1.In2012,thisproportionwas300GUSDoutof72.0TUSD(0.42%).
Assessing thesignificanceof semiconductorson thebasis ofsales volumegrosslyunderestimatesits
impactonworldeconomy,however.Thisisbecausemicroelectronicsisactingasatechnologydriver
thatenablesorexpeditesarangeofotherindustrial,commercial,andserviceactivities.Justconsider
• Computerandsoftwareindustry,
(cid:129) Telecommunicationsandmediaindustry,
(cid:129) Commerce,logistics,andtransportation,
(cid:129) Naturalscienceandmedicine,
(cid:129) Powergenerationanddistribution,and—lastbutnotleast—
(cid:129) Financeandadministration.
Microelectronics thus has an enormous economic leverage as any progress there spurs many, if not
most,innovationsin“downstream”industriesandservices.
A popular example ...
Afterarapidgrowthduringthelastfourdecades,theelectricandelectroniccontentofpassengercars
nowadaysmakesupmorethan20%ofthetotalvalueinsimplercarsandcloseto40%inwell-equipped
vehicles.
What’s more, microelectronics is responsible for the vast majority of improvements that we have
witnessed. Justconsiderelectronicignitionandinjectionthathavesubsequentlymergedandevolved
to become electronic engine management. Add to that anti-lock brakes and anti-skid stability pro-
grams, trigger circuits for airbags, anti-theft equipment, automatic air conditioning, navigation aids,
multiplexedbusses, electronicallycontrolleddrivetrainandsuspension,audio/videoinformationand
entertainment,LEDilluminationandheadlights,nightvisionandcollisionavoidancesystems,hybrid
propulsion,andregenerativebraking.
1TheGDPindicatesthevalueofallgoodsandservicessoldduringsomespecifiedyear.
1
Top-DownDigitalVLSIDesign
©2015ElsevierInc.Allrightsreserved.
2 CHAPTER 1 INTRODUCTION TOMICROELECTRONICS
EDA software &
virtual components
2012: 300 GUSD/a
Semiconductor components
Electronic components
Electronic goods World-wide gross domestic product 2012: 72 TUSD/a
(computers, smartphones,
home entertainment equipment, etc.)
Applications:
(cid:129) Goods with embedded electronics
(machines, cars, cameras, watches, etc.)
(cid:129) Information technology services
(corporate IT, Internet, music download, etc.)
FIGURE1.1
Economicleverageofmicroelectronicson“downstream”industriesandservices.
Forthcominginnovationsincludean48Von-boardsupplynetwork,electronicallydrivenvalvetrains,
brakebywire,drivebywire,advanceddriverassistance systems, and,possibly,entirely autonomous
vehicles. And any future transition to propulsion by other forms of energy is bound to intensify the
importanceofsemiconductorsintheautomotiveindustryevenfurther.
... and its less evident face
Perhaps less obvious but as important are the many contributions of electronics to the processes of
development, manufacturing and servicing. Innovationsbehind the scene of the automotive industry
include computer-aided design (CAD) and finite element analysis, virtual crash tests, computational
fluid dynamics, computer numeric controlled (CNC) machine tools, welding and assembly robots,
computer-integratedmanufacturing(CIM),qualitycontroland processmonitoring,orderprocessing,
supplychainmanagement,anddiagnosticprocedures.
(cid:2)
Thisalmosttotalpenetrationhasbeenmadepossiblebyalong-runningdropofcostperfunctionata
rateof25to29%peryear.Whilecomputing,telecommunication,andentertainmentproductsexisted
beforetheadventofmicroelectronics,today’sanywhere,anytimeinformationandtelecommunication
societywouldnothavebeenpossiblewithout,justcomparetheelectronicdevicesinfig.1.2.
Observation1.1. Microelectronicsistheenablerofinformationtechnology.
On the positive side, microelectronics and information technology improve speed, efficiency, safety,
comfort, and pollution control of industrial products and commercial processes thereby bringing
competitiveadvantagestothosecompaniesthattakeadvantageofthem.
On the negative side, the rapid progress, most of which is ultimately fueled by advances in
semiconductor manufacturing technology, also implies a rapid obsoletion of hardware and software
products,services,know-how,andorganizations.Ahighlycycliceconomyisanotherunfortunatetrait
ofthesemiconductorindustry[1].