BL51User'sGuide:BL51User'sGuide页码，1/112BL51User'sGuideTheBL51Linker/Locatormergessegmentsfromobjectmodules,locatesthem,andcreatesprograms.ThismanualdescribeshowtouseBL51andincludesthefollowingchapters.IntroductionprovidesabriefintroductiontotheBL51Linker.LinkingProgramsdescribeshowtoinvoketheBL51Linkerandprovidesareferencesectionforthelinkerdirectives.LocatingSegmentsdiscusseshowtospecifyyourprogram'smemorymaptothelinkerusingtheavailabledirectives.DataOverlayingdescribeshowthelinkerdeterminesaprogram'scalltreeandusesthatinformationtooverlayvariablesinmemory.CodeBankingdescribeshowtousethelinkertocreatecodebankingprograms.Severalexampleareprovidedtodemonstratedifferenthardwareconfigurationsandtohelpyourapidlygetstarted.Real-TimeProgramsdescribeshowtolinkRTX51andRTX51Tinyapplications.ErrorMessagesliststheerrorsandwarningsyoumayencounterwhileusingtheBL51Linker.RevisionHistoryJuly2005:InitialrevisioninCHMformat.Copyright©Keil,AnARMCompany.Allrightsreserved.BL51IntroductionTheBL51Linker/LocatorcreatesanabsoluteobjectmodulebylinkingtogetherobjectmodulescreatedusingtheKeilA51Assembler,C51Compiler,IntelASM-51Assembler,andIntelPL/M-51Compiler.Objectmodulescreatedbythesetoolsarerelocatableandcannotbedirectlyexecuted(eveniftheyconsistofonlyonesourcemodule).Theymustbelinkedandconvertedintoanabsoluteobjectmodulesusingthelinker.ThefollowingfigureshowshowC51objectmodulesflowthroughtheKeiltoolchain.file://C:\DocumentsandSettings\Administrator\LocalSettings\Temp...2010-10-20BL51User'sGuide:BL51User'sGuide页码，2/112TheBL51Linkerworkswithobjectmodulescreatedbythefollowingdevelopmenttools:KeilA51AssemblerIntelASM-51AssemblerKeilC51CompilerIntelPL/M-51CompilerCopyright©Keil,AnARMCompany.Allrightsreserved.PurposeoftheLinkerfile://C:\DocumentsandSettings\Administrator\LocalSettings\Temp...2010-10-20BL51User'sGuide:BL51User'sGuide页码，3/112ThepurposeoftheBL51Linkeristo:Linkobjectmodulesgeneratedbytheassembler