Chris Kormanyos Real -Time C++ Efficient Object-Oriented and Template Microcontroller Programming 123 Real-Time C++ Christopher Michael Kormanyos Real-Time C++ Efficient Object-Oriented and Template Micro- controller Programming 123 ChristopherMichaelKormanyos Reutlingen Baden-Württemberg Germany ISBN978-3-642-34687-3 ISBN978-3-642-34688-0(eBook) DOI10.1007/978-3-642-34688-0 SpringerHeidelbergNewYorkDordrechtLondon LibraryofCongressControlNumber:2013931231 ACMComputingClassification(1998):C.3,D.2,C.5,B.1 (cid:2)c Springer-VerlagBerlinHeidelberg2013 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerptsinconnection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. 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Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) To thosewho pursuetheartoftechnical creativity Preface Thisbookisapracticalguidetoprogrammingreal-timeembeddedmicrocontroller systems in C++. The C++ language has powerful object-oriented and template features that can improve software design and portability while simultaneously reducingcode complexity and the risk of error. At the same time, C++ compiles highlyefficientnativecode.ThisuniqueandeffectivecombinationmakesC++well suited for programming microcontroller systems that require compact size, high performance,andsafety-criticalreliability. Thetargetaudienceofthisbookincludeshobbyists,students,andprofessionals interested in real-time C++. The reader should be familiar with C or another pro- gramminglanguageandshouldideallyhavehadsomeexposuretomicrocontroller electronics and the performance and size issues prevalent in embedded systems programming. AboutThisBook This is an interdisciplinary book that includes a broad range of topics. Real- worldexampleshavebeencombinedwithbriefdescriptionsinanefforttoprovide an intuitive and straightforward methodology for microcontroller programming inC++.Efficiencyisalwaysinfocus,andnumerousexamplesarebackedupwith real-timeperformancemeasurementsandsize analysesthatquantifythetruecosts ofthecodedowntotheverylastbyteandmicrosecond. Throughoutthechapters,C++isusedinabare-bones,no-frillsfashionwithout relying on any libraries other than those specified in the language standard itself. Thisapproachfacilitatesportability. Thisbookhasthreepartsandseveralappendices.Thethreepartsgenerallybuild oneach otherwith the combinedgoalof providinga coherentand effectivesetof C++methodsthatcanbeusedwithawiderangeofembeddedmicrocontrollers. vii viii Preface • Part I provides a foundation for real-time C++ by covering language technologies. Topics include getting started in real-time C++, object-oriented methods,templateprogramming,andoptimization.Thefirstthreechaptershave aparticularlyhands-onnatureandareintendedtoboostcompetenceinreal-time C++.Chapter6hasauniqueandimportantroleinthatitiswhollydedicatedto optimizationtechniquesappropriateformicrocontrollerprogramminginC++. • Part II presents detailed descriptions of a variety of C++ components that are widely used in microcontroller programming.These componentscan be either usedaspresentedoradaptedforotherprojects.Thispartofthebookusessome of C++’s mostpowerfullanguageelements, suchas class types,templates, and the STL, to develop components for microcontroller register access, low-level drivers,custommemorymanagement,embeddedcontainers,multitasking,etc. • Part III describes mathematical methods and generic utilities that can be employedtosolverecurringproblemsinreal-timeC++. • The appendices include a C++ language tutorial, information on the real-time C++ developmentenvironment, and instructions for building GNU GCC cross compilersandamicrocontrollercircuit. C++ is a rich language with many features and details, the description of which can fill entire bookshelves. This book, however, primarily concentrates on how to use C++ in a real-time microcontroller environment. Along those lines, C++ language tutorials have been held terse, and information on microcontroller hardware and compilers is included only insofar as it is needed for the examples. A suggested list of additional reading material is given in Chap.17 for those seeking supplementary information on C++, the C++ standard library and STL, software design, C++ coding guidelines, the embedded systems toolchain, and microcontrollerhardware. Whenunitsareneededtoexpressphysicalquantities,theMKS(meter,kilogram, second)systemofunitsisused. CompanionCode,Targets, andTools Thecompanioncodeincludesthreeintroductoryprojectsandonereferenceproject. TheintroductoryprojectstreatvariousaspectsofthematerialpresentedinChaps.1 and2. Thereferenceprojectis largerin scope andexercisesmanyofthe methods fromallthechapters. Thecompanioncodeisavailableat https://github.com/ckormanyos/real-time-cpp TheC++techniquesinthisbookspecificallytargetmicrocontrollersinthesmall- to-mediumsizerange.Here,small-to-mediumspansthefollowingapproximatesize andperformanceranges: Preface ix • 4kB:::1-MBprogramcode • 256byte::: 128-kBRAM • 8bit:::32–bitCPU • 8MHz:::200-MHzCPUfrequency Mostofthemethodsdescribedinthisbookare,however,scalable.Assuch,they canbeusedequallywellonlargerorsmallerdevices,evenonPCsandworkstations. Inparticular,theycanbeemployediftheapplicationhasstrictperformanceandsize constraints. A popular 8–bit microcontroller clocked with a frequency of 16MHz has been used as the primary target for benchmarking and testing the code samples in this book. Certain benchmarks have also been performed with a well-known 32–bitmicrocontrollerclocked at 24MHz. An 8–bit microcontrollerand a 32–bit microcontroller have been selected in order to exercise the C++ methods over a widerangeofmicrocontrollerperformance. All the C++ examples and benchmarks in the book and the companion code havebeencompiledwithGNUGCCversions4.6.2and4.7.0.Certainexamplesand benchmarkshavealsobeencompiledwithotherPC-basedcompilers. ThemostrecentspecificationofC++11inISO/IEC14882:2011isusedthrough- outthetext.Atthetimethisbookiswritten,thespecificationofC++11isbrand-new. The adventof C++11 has made C++ significantly more effective and easy to use. Thiswill profoundlyinfluenceC++ programming.The well-informedreaderwill, therefore, want to keep in touch with C++11 best practice as it evolves in the developmentcommunity. Notes onCodingStyle A consistentcodingstyle is used throughoutthe examplesin this bookand in the companioncode. Code samples are written with a fixed-width font. C++ language key- wordsandbuilt-intypesusethesamefont,buttheyareinboldface.Forinstance, constexpr int version = 7; Ingeneral,thenamesofallsymbolssuchasvariables,classtypes,members,and subroutinesare written in lowercase. A single underscore(_) is used to separate words and abbreviationsin names. For instance, a system-tick variable expressed withthisstyleisshowninthecodesamplebelow: unsigned long system_tick;