CS152,Spring2016

CS152ComputerArchitectureandEngineering

Lecture1-Introduc:on

Dr.GeorgeMichelogiannakisEECS,UniversityofCaliforniaatBerkeley

CRD,LawrenceBerkeleyNaFonalLaboratory!

http://inst.eecs.berkeley.edu/~cs152!

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Pronuncia:on

Miheloyannakis

(opFonal)

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WhatisComputerArchitecture?

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ApplicaFon

Physics

Gaptoolargetobridgeinonestep

InitsbroadestdefiniFon,computerarchitectureisthedesignoftheabstrac0onlayersthatallowustoimplementinformaFonprocessingapplicaFonsefficientlyusingavailablemanufacturingtechnologies.

(butthereareexcep0ons,e.g.magne0ccompass)

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WhatisComputerArchitecture?

•  AsetofrulesandmethodsthatdescribethefuncFonality,organizaFonandimplementaFonofcomputersystems.

•  ComputerArchitectureisthescienceandartofselecFngandinterconnecFnghardwarecomponentstocreatecomputersthatmeetfuncFonal,performanceandcostgoals.

•  Computerarchitectureactsastheintermediatebetweenprogrammersanddevices(e.g.,VLSI).

•  Whatareyouheretolearn?

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Abstrac:onLayersinModernSystems

Algorithm

Gates/Register-TransferLevel(RTL)

ApplicaFon

InstrucFonSetArchitecture(ISA)

OperaFngSystem/VirtualMachines

Microarchitecture

Devices

ProgrammingLanguage

Circuits

Physics

EE141CS150

CS162

CS170CS164

EE143

CS152

UCBEECSCourses

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Costofso\waredevelopmentmakescompaFbilityamajorforceinmarket

ArchitectureCon:nuallyChanging

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ApplicaFons

Technology

ApplicaFonssuggesthowtoimprovetechnology,providerevenuetofunddevelopment

ImprovedtechnologiesmakenewapplicaFonspossible

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Example:x86BackwardsCompa:bility

•  Intel’s8086wasreleasedin1978with~50instrucFons•  Today,x86has~650withallextensions

–  Mostarerarelyemidedbycompilers

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Compu:ngDevicesThen…

EDSAC,UniversityofCambridge,UK,1949

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Compu:ngDevicesNow

Robots

Supercomputers Automobiles

Laptops

Set-top boxes

Smart phones

Servers Media Players

Sensor Nets

Routers

Cameras Games

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Moore’sLaw

•  TheobservaFonthat,overthehistoryofcompuFnghardware,thenumberoftransistorsinadenseintegratedcircuit(chip)hasdoubledapproximatelyeverytwoyears.

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DesignComplexity

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DesignCapacity

•  In1978,Intelcoulddesignachip(8086)with29,000transistors

•  In2012,2,104million(IvyBridge)

•  Rocket(RISC-V)whichyou’llbeusinghas75+milliontransistors

•  DoeshumanitygetsmarterwithFme?

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ComputerArchitectsThen

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ComputerArchitectsNow

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TechnologyTrends

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PowerDissipa:on

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PowerWallinModernProcessors

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While at the same time chips keep getting larger.

Therefore, not all of the chip can be powered on at the same time

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TheEndoftheUniprocessorEra

Singlebiggestchangeinthehistoryofcompu0ngsystems

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WeWentFromThis

•  Cray-1

•  Singleprocessor

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ToThis

•  Titan,anXK7supercomputeratOakRidgeNaFonalLaboratory(CrayXT3)(299,008AMDOpteroncores)

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Result:SimpleCores

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J. Huh, D.C. Burger, and S.W. Keckler. Exploring the Design Space of Future CMPs.

In International Conference on Parallel Architectures and Compilation Techniques (PACT), September, 2001

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Result:SimpleCores

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Result:Specializa:on

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BeforeThat:DennardScaling

•  Power=AxCxFxV2

–  A:AcFvityfactor–  C:Capacitance–  F:Frequency–  V:Voltage

•  Capacitanceisrelatedtoarea–  So,asthesizeofthetransistorsshrunk,andthevoltagewasreduced,circuitscouldoperateathigherfrequenciesatthesamepower

•  Butleakagecurrentandthresholdvoltageoftransistorssetalowerboundforvoltage

•  Transistorsgetsmaller,theirpoweristhesame->Powerdensityincreases

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ALITTLEHISTORYLearnfromthemistakesofothers

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An:kytheraMechanism

•  FoundinaGreekshipbelievedtohavesankaround80B.C.

•  Itaccuratelypredictedlunarandsolareclipses,aswellassolar,lunarandplanetaryposiFons–  Size:8inchesacross

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DifferenceEngine

1855.Cancomputeany6thdegreepolynomialbycalculaFngthedifferencebetween2Dmatrixelements

Speed:33to4432-digitnumbers

perminute!

Now the machine is at the Smithsonian

n

d2(n)

d1(n)

f(n)

0

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1

2

2

2

3

2

4

2

4 6 8

43 47 53 61

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HarvardMarkI

• Builtin1944inIBMEndico`laboratories– HowardAiken–ProfessorofPhysicsatHarvard– Essen:allymechanicalbuthadsomeelectro-magne:callycontrolledrelaysandgears

– Weighed5tonsandhad750,000components– Asynchronizingclockthatbeatevery0.015seconds(66Hz)–  InspiredbyCharlesBabbage’sanaly:cengine

Performance: 0.3 seconds for addition 6 seconds for multiplication 1 minute for a sine calculation Decimal arithmetic No Conditional Branch!

Broke down once a week!

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ElectronicNumericalIntegratorandComputer(ENIAC)•  InspiredbyAtanasoffandBerry,EckertandMauchlydesignedand

builtENIAC(1943-45)attheUniversityofPennsylvania•  Thefirst,completelyelectronic,operaFonal,general-purpose

analyFcalcalculator!–  30tons,72squaremeters,200KW

•  Performance–  Readin120cardsperminute–  AddiFontook200µs,Division6ms–  1000FmesfasterthanMarkI

•  Notveryreliable!

Application: Ballistic calculations angle = f (location, tail wind, cross wind, air density, temperature, weight of shell, propellant charge, ... )

WW-2 Effort

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Computersinmid50’s

•  Hardwarewasexpensive•  StoreinstrucFonsweresmall(1000words)

⇒Noresidentsystemso\ware!

•  MemoryaccessFmewas10to50Fmesslowerthantheprocessorcycle⇒InstrucFonexecuFonFmewastotallydominatedbythememory

reference0me.

•  TheabilitytodesigncomplexcontrolcircuitstoexecuteaninstrucFonwasthecentraldesignconcernasopposedtothespeedofdecodingoranALUoperaFon

•  Programmer’sviewofthemachinewasinseparablefromtheactualhardwareimplementaFon

•  MTBF20minuteswasstateoftheart

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Compa:bilityProblematIBM

By early 60’s, IBM had 4 incompatible lines of computers!

701 → 7094 650 → 7074 702 → 7080 1401 → 7010

Each system had its own

•  Instruction set •  I/O system and Secondary Storage: magnetic tapes, drums and disks •  assemblers, compilers, libraries,... •  market niche

business, scientific, real time, ...

⇒ IBM 360

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IBM360:DesignPremisesAmdahl,BlaauwandBrooks,1964

• Thedesignmustlenditselftogrowthandsuccessormachines• GeneralmethodforconnecFngI/Odevices• Totalperformance-answerspermonthratherthanbitspermicrosecond⇒ programmingaids

• MachinemustbecapableofsupervisingitselfwithoutmanualintervenFon

• Built-inhardwarefaultcheckingandlocaFngaidstoreducedownFme

• SimpletoassemblesystemswithredundantI/Odevices,memoriesetc.forfaulttolerance

• SomeproblemsrequiredfloaFng-pointlargerthan36bits

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IBM360:AGeneral-PurposeRegister(GPR)Machine• ProcessorState

–  16General-Purpose32-bitRegisters» maybeusedasindexandbaseregister

» Register0hassomespecialproper0es–  4FloaFngPoint64-bitRegisters–  AProgramStatusWord(PSW)

» PC,Condi0oncodes,Controlflags•  A32-bitmachinewith24-bitaddresses

–  ButnoinstrucFoncontainsa24-bitaddress!•  DataFormats

–  8-bitbytes,16-bithalf-words,32-bitwords,64-bitdouble-words

The IBM 360 is why bytes are 8-bits long today!

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IBM360:Ini:alImplementa:ons

Model30 ... Model70Storage 8K-64KB 256K-512KBDatapath 8-bit 64-bitCircuitDelay 30nsec/level 5nsec/levelLocalStore MainStore TransistorRegistersControlStore Readonly1µsec ConvenFonalcircuits

IBM360instruc0onsetarchitecture(ISA)completelyhidtheunderlyingtechnologicaldifferencesbetweenvariousmodels.Milestone:ThefirsttrueISAdesignedasportablehardware-soRwareinterface!

Withminormodifica0onsits0llsurvivestoday!

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IBM360:47yearslater…ThezSeriesz11Microprocessor

•  5.2GHzinIBM45nmPD-SOICMOStechnology•  1.4billiontransistorsin512mm2•  64-bitvirtualaddressing

–  originalS/360was24-bit,andS/370was31-bitextension

• Quad-coredesign•  Three-issueout-of-ordersuperscalarpipeline• Out-of-ordermemoryaccesses•  Redundantdatapaths

–  everyinstrucFonperformedintwoparalleldatapathsandresultscompared

•  64KBL1I-cache,128KBL1D-cacheon-chip•  1.5MBprivateL2unifiedcachepercore,on-chip• On-Chip24MBeDRAML3cache•  Scalesto96-coremulFprocessorwith768MBofsharedL4eDRAM[ IBM, HotChips, 2010]

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StorageDevicesAlsoProgressed

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Magne:cStorageDevices

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7.25 MB

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LOGISTICS

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RelatedCourses

CS61C CS152

CS150

Basiccomputerorganiza:on,firstlookatpipelines+caches

ComputerArchitecture,Firstlookatparallelarchitectures

DigitalLogicDesign,FPGAs

Strong

Prerequisite

CS250

VLSI Systems Design

CS252

GraduateComputerArchitecture,Advanced

Topics

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CS61CvsCS152vsCS252

•  CS152focusesoninteracFonofso\wareandhardware–  morearchitectureandlessdigitalengineering–  moreusefulforOSdevelopers,compilerwriters,performanceprogrammers

•  Muchofthematerialyou’lllearnthistermwaspreviouslyinCS252–  SomeofthecurrentCS61CwasinCS252over20yearsago!–  Maybeevery10years,shi\CS252->CS152->CS61C?

•  CS152beginswhereCS61Cle\off(withoverlap)

•  CS252delvesintomoredetailandhasaresearchproject

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CS152Execu:veSummary

TheprocessoryoubuiltinCS61C

Plus,thetechnologybehindchip-scalemulFprocessors(CMPs)andgraphicsprocessingunits(GPUs)

Whatyou’llunderstandandexperimentwithinCS152

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CS152StructureandSyllabusFivemodules

1.  Simplemachinedesign(ISAs,microprogramming,unpipelinedmachines,IronLaw,simplepipelines)

2. Memoryhierarchy(DRAM,caches,opFmizaFons)plusvirtualmemorysystems,excepFons,interrupts

3.  Complexpipelining(score-boarding,out-of-orderissue)4.  Explicitlyparallelprocessors(vectormachines,VLIW

machines,mulFthreadedmachines)5. MulFprocessorarchitectures(memorymodels,cache

coherence,synchronizaFon)

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CS152AdministriviaInstructor:GeorgeMichelogiannakis,mihelog@eecs!

OfficeHours:A\erlectures,Wednesdays11-12:30pm341ASodaT.A.: ColinSchmidt,colins@eecs

OfficeHours:Tuesday2-4pm651SodaLectures: M/W,9-10:30AM,306Soda

SecFon: Th2PM-4PM,9105LaFmerText: ComputerArchitecture:AQuan0ta0veApproach,

HennesseyandPaWerson,5thEdi0on(2012)ReadingsassignedfromthisediFon,somereadingsavailableinolder

ediFons–seewebpage.

Webpage:http://inst.eecs.berkeley.edu/~cs152!Lecturesavailableonline

Piazzza: http://piazza.com/berkeley/spring2016/cs152

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CS152CourseComponents

•  15%Problemsets(onepermodule)–  Intendedtohelpyoulearnthematerial.Feelfreetodiscusswithotherstudentsandinstructors,butmustturninyourownsoluFons.Gradingbasedmostlyoneffort,butquizzesassumethatyouhaveworkedthroughallproblems.SoluFonsreleaseda\erPSshandedin

•  45%Quizzes(onepermodule)–  In-class,closed-book,nocalculators,nosmartphones,nolaptops,...–  Basedonlectures,readings,problemsets,andlabs

•  40%Labs(onepermodule)–  Labsuseadvancedprocessorandsystemsimulators–  Directedplusopen-endedsecFonstoeachlab

•  SecFonswillrevieweachoftheabove•  Checkthewebsitefordeadlines!•  SignupforPiazza!

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CS152Labs•  Eachlabhasdirectedplusopen-endedassignments•  DirectedporFon(2/7)isintendedtoensurestudentslearnmainconceptsbehindlab–  Eachstudentmustperformownlabandhandintheirownlabreport

•  Open-endedassignment(5/7)istoallowyoutoshowyourcreaFvity–  Roughlya“mini-project”

»  E.g.,tryanarchitecturalideaandmeasurepotenFal,ortrytoimproveadesign.NegaFveresultsOK(ifexplainable!)

–  Studentscanworkindividuallyoringroupsoftwo–  Groupopen-endedlabreportsmustbehandedinseparately(butstatewhoyouworkedwith)

–  Studentscanworkindifferentgroupsfordifferentassignments

•  LabreportsmustbereadableEnglishsummaries•  Twofreetwo-dayextensionsperstudent•  YoumayhavetolearnscripFnglanguages

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RISC-VISA

•  RISC-Visanewsimple,clean,extensibleISAwedevelopedatBerkeleyforeducaFonandresearch–  RISC-I/II,firstBerkeleyRISCimplementaFons–  BerkeleyresearchmachinesSOAR/SPURconsideredRISC-III/IV

•  BothofthedominantISAs(x86andARM)aretoocomplextouseforteaching

•  RISC-VISAmanualavailableonwebpage–  See“resources”onclasswebsite

•  FullGCC-basedtoolchainavailable

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Chiselsimulators

•  ChiselisanewhardwaredescripFonlanguagewedevelopedatBerkeleybasedonScala–  ConstrucFngHardwareinaScalaEmbeddedLanguage

•  LabswilluseRISC-VprocessorsimulatorsderivedfromChiselprocessordesigns–  GivesyoumuchmoredetailedinformaFonthanothersimulators–  CanmaptoFPGAorrealchiplayout

•  YouneedtolearnsomeminimalChiselinCS152,butwe’llmakeChiselRTLsourceavailablesoyoucanseeallthedetailsofourprocessors

•  CandolabprojectsbasedonmodifyingtheChiselRTLcodeifdesired

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ChiselDesignFlow

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ChiselDesignDescripFon

C++code

FPGAVerilog

ASICVerilog

C++Simulator

C++Compiler

ChiselCompiler

FPGAEmulaFon

FPGATools

GDSLayout

ASICTools

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FAMILIARITYQUIZ

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PipelinedProcessor

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VirtualAddresses

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Caches

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BirdsCache(hoard)too!

•  Sameidea.Bringvaluableobjectsclose•  AcornWoodpeckersstoretheirfoodinholesdrilledintrees

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InConclusion

•  ComputerArchitecture>>ISAsandRTL•  CS152isaboutinteracFonofhardwareandso\ware,anddesignofappropriateabstracFonlayers

•  ComputerarchitectureisshapedbytechnologyandapplicaFons–  Historyprovideslessonsforthefuture

•  ComputerScienceatthecrossroadsfromsequenFaltoparallelcompuFng–  SalvaFonrequiresinnovaFoninmanyfields,includingcomputerarchitecture

•  ReadChapter1&AppendixAfornextFme!

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Acknowledgements

•  Theseslidescontainmaterialdevelopedandcopyrightby:–  Arvind(MIT)–  KrsteAsanovic(MIT/UCB)–  JoelEmer(Intel/MIT)–  JamesHoe(CMU)–  JohnKubiatowicz(UCB)–  DavidPaderson(UCB)–  Variouswebsitesandpapers

•  MITmaterialderivedfromcourse6.823•  UCBmaterialderivedfromcourseCS252