Introduction to embedded systems: a cyber-physical systems approach

585 Pages·2017·26.24 MB·English

by  Edward Ashford Lee

computer science/electrical engineering
E I Edward Ashford Lee and
Introduction to Embedded Systems N
M
A Cyber-Physical Systems Approach T
Sanjit Arunkumar Seshia
second edition B R
Edward Ashford Lee and Sanjit Arunkumar Seshia E O
D
D
The most visible use of computers and software is processing information for human consumption. The vast majority D
U
of computers in use, however, are much less visible. They run the engine, brakes, seatbelts, airbag, and audio system E
C
in your car. They digitally encode your voice and construct a radio signal to send it from your cell phone to a base sta- D
tion. They command robots on a factory floor, power generation in a power plant, processes in a chemical plant, and S TI INTRODUCTION TO
traffic lights in a city. These less visible computers are called embedded systems, and the software they run is called O
Y
embedded software. The principal challenges in designing and analyzing embedded systems stem from their interac- N
S
tion with physical processes. This book takes a cyber-physical approach to embedded systems, introducing the engi- T T EMBEDDED SYSTEMS
neering concepts underlying embedded systems as a technology and as a subject of study. The focus is on modeling, E O
design, and analysis of cyber-physical systems, which integrate computation, networking, and physical processes. M
The second edition offers two new chapters, several new exercises, and other improvements. The book can be
S
A CYBER-PHYSICAL SYSTEMS
used as a textbook at the advanced undergraduate or introductory graduate level and as a professional reference
for practicing engineers and computer scientists. Readers should have some familiarity with machine structures,
computer programming, basic discrete mathematics and algorithms, and signals and systems. APPROACH
Edward Ashford Lee is the Robert S. Pepper Distinguished Professor in the Department of Electrical Engineering and s SA
Cmoemntp ouft eErl eScctireicnacle Esn agti nteheer Uinngi vaenrds iCtyo omfp Cuatelirfo Srcniiean, cBeesr kaetl ethye. SUannivjiet rAsrituyn okfu Cmaalrif oSrensiah,i aB iesr kae Pleryo.fessor in the Depart- econd YSTE CYB
“Books titled Introduction to Embedded Systems traditionally focus on computer hardware and software. By taking e MER
Ast aCnydb earn-dP hdyessiicganl tShyes tceommsp Autpinpgro saycshte, mLese t haantd m Saekseh ioau gr iwveo srltdu dfuennctsti othne. Ninot eogthraetre bdo poekr spproevcitdivees tshuecyh n ae ecdo mtop ruenhdeenr-- dition S AP-PHY Second Edition Modeling
sive introduction to embedded systems for real-time applications.” PS
—Bruce H. Krogh, Professor of Electrical and Computer Engineering, Carnegie Mellon University ROIC
AA Design
“Introduction to Embedded Systems by Lee and Seshia is an introductory yet rigorous textbook for the future Internet CL

of Things engineer. It provides a unified systems view of computing and the physical world that will be the foundation H
of the 21st-century Internet of Things revolution.”
—George J. Pappas, Joseph Moore Professor, University of Pennsylvania Analysis
“Designers of embedded systems are only too often overwhelmed by the many skills and disciplines that have to be
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mastered: from writing device drivers, to worst case execution time analysis, to formal verification and modeling of
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continuous time systems. This book by Lee and Seshia is an excellent guide to bringing order into these complex- nw
ities of design by discerning the fundamental from the detail, the essential property from the accidental aspect. It jita
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presents all the indispensable knowledge areas for an embedded systems designer and leaves out what can be Ad
delegated to other specialized disciplines.” ru A
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—Axel Jantsch, Professor of Systems on Chips, Institute of Computer Technology, TU Wien, Vienna; author of Mod- kh
eling Embedded Systems and SoC’s ufo
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“The outstanding property of this textbook is the combination of mathematical rigor and comprehensiveness. It is ad
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presented with numerous examples and with such quality that understanding the material is easy. Introduction to Se
Embedded Systems is a must-read for those wanting to master the complexity of what is today the key enabling ee
s a
technology in most every complex system surrounding us: embedded and cyber-physical systems.” hn
—Werner Damm, Director, Interdisciplinary Research Center on Cooperative Critical Systems, Carl von Ossietzky iad

University of Oldenburg
978-0-262-53381-2
The MIT Press
Massachusetts Institute of Technology 90000
Cambridge, Massachusetts 02142
http://mitpress.mit.edu 9 780262 533812
Copyright(cid:13)c 2017
EdwardAshfordLee&SanjitArunkumarSeshia
ThisworkislicensedunderaCreativeCommons
Attribution-NonCommercial-NoDerivatives4.0InternationalLicense.
SecondEdition,Version2.2
ISBN:978-0-262-53381-2
Pleasecitethisbookas:
E.A.LeeandS.A.Seshia,
IntroductiontoEmbeddedSystems-ACyber-PhysicalSystemsApproach,
SecondEdition,MITPress,2017.
Thisbookisdedicatedtoourfamilies.
Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
1 Introduction 1
1.1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 MotivatingExample . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 TheDesignProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
I ModelingDynamicBehaviors 17
2 ContinuousDynamics 18
2.1 NewtonianMechanics. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 ActorModels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3 PropertiesofSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.4 FeedbackControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
CONTENTS
3 DiscreteDynamics 42
3.1 DiscreteSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.2 TheNotionofState . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.3 Finite-StateMachines . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.4 ExtendedStateMachines . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.5 Nondeterminism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.6 BehaviorsandTraces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4 HybridSystems 78
4.1 ModalModels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.2 ClassesofHybridSystems . . . . . . . . . . . . . . . . . . . . . . . . . 82
4.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
5 CompositionofStateMachines 109
5.1 ConcurrentComposition . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.2 HierarchicalStateMachines . . . . . . . . . . . . . . . . . . . . . . . . 126
5.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
6 ConcurrentModelsofComputation 135
6.1 StructureofModels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
6.2 Synchronous-ReactiveModels . . . . . . . . . . . . . . . . . . . . . . . 141
6.3 DataflowModelsofComputation. . . . . . . . . . . . . . . . . . . . . . 147
6.4 TimedModelsofComputation . . . . . . . . . . . . . . . . . . . . . . . 162
6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Lee&Seshia,IntroductiontoEmbeddedSystems v
CONTENTS
II DesignofEmbeddedSystems 178
7 SensorsandActuators 179
7.1 ModelsofSensorsandActuators . . . . . . . . . . . . . . . . . . . . . . 181
7.2 CommonSensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
7.3 Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
7.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
8 EmbeddedProcessors 210
8.1 TypesofProcessors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
8.2 Parallelism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
8.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
9 MemoryArchitectures 239
9.1 MemoryTechnologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
9.2 MemoryHierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
9.3 MemoryModels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
9.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
10 InputandOutput 260
10.1 I/OHardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
10.2 SequentialSoftwareinaConcurrentWorld . . . . . . . . . . . . . . . . 272
10.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
11 Multitasking 291
11.1 ImperativePrograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
11.2 Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
vi Lee&Seshia,IntroductiontoEmbeddedSystems
CONTENTS
11.3 ProcessesandMessagePassing . . . . . . . . . . . . . . . . . . . . . . . 311
11.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
12 Scheduling 322
12.1 BasicsofScheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
12.2 RateMonotonicScheduling . . . . . . . . . . . . . . . . . . . . . . . . 329
12.3 EarliestDeadlineFirst . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
12.4 SchedulingandMutualExclusion . . . . . . . . . . . . . . . . . . . . . 339
12.5 MultiprocessorScheduling . . . . . . . . . . . . . . . . . . . . . . . . . 344
12.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
III AnalysisandVerification 357
13 InvariantsandTemporalLogic 358
13.1 Invariants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
13.2 LinearTemporalLogic . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
13.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372
14 EquivalenceandRefinement 376
14.1 ModelsasSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . 377
14.2 TypeEquivalenceandRefinement . . . . . . . . . . . . . . . . . . . . . 378
14.3 LanguageEquivalenceandContainment . . . . . . . . . . . . . . . . . . 381
14.4 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
14.5 Bisimulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
14.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Lee&Seshia,IntroductiontoEmbeddedSystems vii
CONTENTS
15 ReachabilityAnalysisandModelChecking 404
15.1 OpenandClosedSystems . . . . . . . . . . . . . . . . . . . . . . . . . 405
15.2 ReachabilityAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
15.3 AbstractioninModelChecking . . . . . . . . . . . . . . . . . . . . . . . 413
15.4 ModelCheckingLivenessProperties . . . . . . . . . . . . . . . . . . . . 417
15.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
16 QuantitativeAnalysis 427
16.1 ProblemsofInterest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
16.2 ProgramsasGraphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
16.3 FactorsDeterminingExecutionTime . . . . . . . . . . . . . . . . . . . . 435
16.4 BasicsofExecutionTimeAnalysis . . . . . . . . . . . . . . . . . . . . . 442
16.5 OtherQuantitativeAnalysisProblems . . . . . . . . . . . . . . . . . . . 451
16.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455
17 SecurityandPrivacy 459
17.1 CryptographicPrimitives . . . . . . . . . . . . . . . . . . . . . . . . . . 461
17.2 ProtocolandNetworkSecurity . . . . . . . . . . . . . . . . . . . . . . . 469
17.3 SoftwareSecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474
17.4 InformationFlow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
17.5 AdvancedTopics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485
17.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491
viii Lee&Seshia,IntroductiontoEmbeddedSystems
CONTENTS
IV Appendices 492
A SetsandFunctions 493
A.1 Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493
A.2 RelationsandFunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . 494
A.3 Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501
B ComplexityandComputability 502
B.1 EffectivenessandComplexityofAlgorithms . . . . . . . . . . . . . . . . 503
B.2 Problems,Algorithms,andPrograms . . . . . . . . . . . . . . . . . . . . 506
B.3 TuringMachinesandUndecidability . . . . . . . . . . . . . . . . . . . . 508
B.4 Intractability: PandNP . . . . . . . . . . . . . . . . . . . . . . . . . . . 514
B.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519
Bibliography 521
NotationIndex 541
NotationIndex 541
Index 543
Lee&Seshia,IntroductiontoEmbeddedSystems ix
Preface
What This Book Is About
The most visible use of computers and software is processing information for human
consumption. We use them to write books (like this one), search for information on
the web, communicate via email, and keep track of financial data. The vast majority of
computersinuse,however,aremuchlessvisible. Theyruntheengine,brakes,seatbelts,
airbag, and audio system in your car. They digitally encode your voice and construct a
radiosignaltosenditfromyourcellphonetoabasestation. Theycontrolyourmicrowave
oven,refrigerator,anddishwasher. Theyrunprintersrangingfromdesktopinkjetprinters
tolargeindustrialhigh-volumeprinters. Theycommandrobotsonafactoryfloor,power
generationinapowerplant,processesinachemicalplant,andtrafficlightsinacity. They
searchformicrobesinbiologicalsamples,constructimagesoftheinsideofahumanbody,
and measure vital signs. They process radio signals from space looking for supernovae
and for extraterrestrial intelligence. They bring toys to life, enabling them to react to
humantouchandtosounds. Theycontrolaircraftandtrains. Theselessvisiblecomputers
arecalledembeddedsystems,andthesoftwaretheyruniscalledembeddedsoftware.
Despitethiswidespreadprevalenceofembeddedsystems,computersciencehas,through-
outitsrelativelyshorthistory,focusedprimarilyoninformationprocessing. Onlyrecently
haveembeddedsystemsreceivedmuchattentionfromresearchers. Andonlyrecentlyhas