MPASM Assembler Help · Assembler Migration Path Since MPASM assembler is a universal assembler for all PICmicro MCU devices, an application developed for the PIC16C54 can be easily

MicrochipTechnologyInc.Microchip'sWebSiteVoice:(480)792-7200Fax:(480)899-9210

Microchip'sE-mailAddress

MPASMAssemblerOverview

AnoverviewofMPASMassembleranditscapabilitiesispresented.

WhatisMPASMAssembler

AssemblerMigrationPathAssemblerCompatibilityIssuesHowMPASMAssemblerHelpsYou

http://www.microchip.com

mailto:[email protected]



WhatisMPASMAssembler

MPASMassembler(theassembler)isacommand-lineorWindows-basedPCapplicationthatprovidesaplatformfordevelopingassemblylanguagecodeforMicrochip'sPICmicromicrocontroller(MCU)families.Generically,MPASMassemblerwillrefertotheentiredevelopmentplatformincludingthemacroassemblerandutilityfunctions.

MPASMassemblersupportsallPICmicroMCU,memory,andsecuredata(KeeLoq))productsfromMicrochipTechnologyInc.





AssemblerMigrationPath

SinceMPASMassemblerisauniversalassemblerforallPICmicroMCUdevices,anapplicationdevelopedforthePIC16C54canbeeasilytranslatedintoaprogramforthePIC16C71.Thiswouldrequirechangingtheinstructionmnemonicsthatarenotthesamebetweenthedevices(assumingthatregisterandperipheralusageweresimilar).Therestofthedirectiveandmacrolanguagewillbethesame.





AssemblerCompatibilityIssues

MPASMassembleriscompatiblewithallMicrochipPICmicroMCUdevelopmentsystemscurrentlyinproduction.ThisincludesMPLABSIM(PICmicroMCUdiscrete-eventsimulator),MPLABICE2000(PICmicroMCUin-circuitemulator),MPLABICD2(in-circuitdebugger-PIC18parts),PROMATEII(deviceprogrammer)andPICSTARTPlus(low-costdevelopmentprogrammer).

MPASMassemblersupportsacleanandconsistentmethodofspecifyingradix.Youareencouragedtodevelopnewcodeusingthemethodsdescribedwithinthisdocument,eventhoughcertainoldersyntaxesmaybesupportedforcompatibilityreasons.





HowMPASMAssemblerHelpsYou

MPASMassemblerprovidesauniversalsolutionfordevelopingassemblycodeforallofMicrochip's12-bit,14-bit,16-bit,andEnhanced16-bitcorePICmicroMCUs.Notablefeaturesinclude:

AllPICmicroMCUInstructionSets

CommandLineInterfaceCommandShellInterfacesRichDirectiveLanguageFlexibleMacroLanguageMPLABIDECompatibility





GettingStartedwithMPASMAssembler

Anoverviewofassembler(MPASMassembler)operationandinstructionsfortheinstallationofMPASMassembleronyoursystemisshown.

OverviewofAssembler

AssemblerInput/OutputFilesAssemblerInstallation



OverviewofAssembler

MPASMassemblercanbeusedintwoways:

Togenerateabsolutecodethatcanbeexecuteddirectlybyamicrocontroller.

Togenerateobjectcodethatcanbelinkedwithotherseparatelyassembledorcompiledmodules.

GeneratingAbsoluteCode

AbsolutecodeisthedefaultoutputfromMPASMassembler.Thisprocessisshownbelow.

Whenasourcefileisassembledinthismanner,allvaluesusedinthesourcefilemustbedefinedwithinthatsourcefile,orinfilesthathavebeenexplicitlyincluded.Ifassemblyproceedswithouterrors,aHEXfilewillbegenerated,containingtheexecutablemachinecodeforthetargetdevice.Thisfilecanthenbeusedinconjunctionwithadeviceprogrammertoprogramthemicrocontroller.

GeneratingObjectCode

MPASMassembleralsohastheabilitytogenerateanobjectmodulethatcanbelinkedwithothermodulesusingMicrochip'sMPLINKlinkertoformthefinalexecutablecode.Thismethodis

veryusefulforcreatingreusablemodulesthatdonothavetoberetestedeachtimetheyareused.

RelatedmodulescanalsobegroupedandstoredtogetherinalibraryusingMicrochip'sMPLIBlibrarian.Requiredlibrariescanbespecifiedatlinktime,andonlytheroutinesthatareneededwillbeincludedinthefinalexecutable.

RefertoRelocatableObjectsformoreinformationonthe



differencesbetweenabsoluteandobjectassembly.



AssemblerInput/OutputFiles

Thesearethedefaultfileextensionsusedbytheassemblerandtheassociatedutilityfunctions.

TABLE:INPUTFILESSourceCode(.asm) Defaultsourcefileextensioninputtoassembler.IncludeFile(.inc) Include(header)file

TABLE:OUTPUTFILESListingFile(.lst) Defaultoutputextensionforlistingfilesgeneratedbyassembler.ErrorFile(.err) Outputextensionfromassemblerforerrorfiles.HexFileFormats(.hex,.hxl,.hxh) Outputextensionfromassemblerforhexfiles.

SymbolandDebugFile(.cod)

Outputextensionforthesymbolanddebugfile.ThisfilemaybeoutputfromassemblerorMPLINKlinker.

ObjectFile(.o) Outputextensionfromassemblerforobjectfiles.

SourceCode(.asm)

Assemblysourcecodeisoneprogramminglanguageyoumayusetodevelopyourapplication.ThesourcecodefilemaybecreatedusinganyASCIItextfileeditor.Itshouldconformtothefollowingbasicguidelines.

Eachlineofthesourcefilemaycontainuptofourtypesofinformation:

Labels

MnemonicsOperandsComments

Theorderandpositionoftheseareimportant.Labelsmuststartincolumnone.Mnemonicsmaystartincolumntwoorbeyond.

Operandsfollowthemnemonic.Commentsmayfollowtheoperands,mnemonicsorlabels,andcanstartinanycolumn.Themaximumcolumnwidthis255characters.

Whitespaceoracolonmustseparatethelabelandthemnemonic,andthemnemonicandtheoperand(s).Multipleoperandsmustbeseparatedbyacomma.

SampleMPASMAssemblerSourceCode(Showsmultipleoperands)

;;SampleMPASMSourceCode.Forillustrationonly.;listp=16c54DestequH'0B'orgH'01FF'gotoStartorgH'0000'StartmovlwH'0A'movwfDestbcfDest,3gotoStartend

Labels

Alabelmuststartincolumn1.Itmaybefollowedbyacolon(:),space,tabortheendofline.

Labelsmustbeginwithanalphacharacteroranunderbar(_)andmaycontainalphanumericcharacters,theunderbarandthequestionmark.

Note:Donotuselabelswithaleadingunderscoreandnumber,e.g.,_2NDLOOP.Also,donotusetheassemblerreservedwordHaltasalabel.

Labelsmaybeupto32characterslong.Bydefaulttheyarecasesensitive,butcasesensitivitymaybeoverriddenbyacommandlineoption.Ifacolonisusedwhendefiningalabel,itistreatedasalabeloperatorandnotpartofthelabelitself.

Mnemonics

Assemblerinstructionmnemonics,assemblerdirectivesandmacrocallsmustbeginincolumntwoorgreater.Ifthereisalabelonthesameline,instructionsmustbeseparatedfromthatlabelbyacolon,orbyoneormorespacesortabs.

Operands

Operandsmustbeseparatedfrommnemonicsbyoneormorespaces,ortabs.Multipleoperandsmustbeseparatedbycommas.

Comments

MPASMassemblertreatsanythingafterasemicolonasacomment.Allcharactersfollowingthesemicolonareignoredthroughtheendoftheline.Stringconstantscontainingasemicolonareallowedandarenotconfusedwithcomments.

IncludeFile(.inc)

Assemblerinclude,orheader,file.Usuallycontainsdevice-specificregisterandbitassignments.

Asanexample,toaddthestandardheaderfileforthePIC18F452devicetoyourassemblycode,use:

#include<p18f452.inc>

ListingFile(.lst)

Alistingfileprovidesamappingofsourcecodetomachineinstructions.MPASMassemblerandMPLINKlinkercangeneratelistingfiles.

SampleMPASMAssemblerListingFile

Theproductnameandversion,theassemblydateandtime,andthepagenumberappearatthetopofeverypage.

Thefirstcolumnofnumberscontainsthebaseaddressinmemorywherethecodewillbeplaced.Thesecondcolumndisplaysthe32-bitvalueofanysymbolscreatedwiththeSET,EQU,VARIABLE,CONSTANT,orCBLOCKdirectives.Thethirdcolumnisreservedforthemachineinstruction.ThisisthecodethatwillbeexecutedbythePICmicroMCU.Thefourthcolumnliststheassociatedsourcefilelinenumberforthisline.Theremainderofthelineisreservedforthesourcecodelinethatgeneratedthemachinecode.

Errors,warnings,andmessagesareembeddedbetweenthesourcelinesandpertaintothefollowingsourceline.

Thesymboltablelistsallsymbolsdefinedintheprogram.Thememoryusagemapgivesagraphicalrepresentationofmemoryusage.'X'marksausedlocationand'-'marksmemorythatisnotusedbythisobject.Thememorymapisnotprintedifanobjectfileisgenerated.

MPASM01.99.21IntermediateMANUAL.ASM5-30-199715:31:05PAGE1LOCOBJECTCODELINESOURCETEXTVALUE00001;00002;SampleMPASMSourceCode.Forillustrationonly.00003;

00004listp=16c540000000B00005DestequH'0B'0000601FF00007orgH'01FF'01FF0A0000008gotoStart00009000000010orgH'0000'0001100000C0A00012StartmovlwH'0A'0001002B00013movwfDest00020A0000014gotoStart0001500016endMPASM01.99.21IntermediateMANUAL.ASM5-30-199715:31:05PAGE2SYMBOLTABLELABELVALUEDest0000000BStart00000000__16C5400000001MEMORYUSAGEMAP('X'=Used,'-'=Unused)0000:XXX-------------------------------------------------------------01C0:---------------------------------------------------------------XAllothermemoryblocksunused.ProgramMemoryWordsUsed:4ProgramMemoryWordsFree:508Errors:0Warnings:0reported,0suppressedMessages:0reported,0suppressed

ErrorFile(.err)

MPASMassembler,bydefault,generatesanerrorfile.Thisfilecanbeusefulwhendebuggingyourcode.TheMPLABIDESourceLevelDebuggerwillautomaticallyopenthisfileinthecaseofanerror.Theformatofthemessagesintheerrorfileis:

<type>[<number>]<file><line><description>

Forexample:

Error[113]C:\PROG.ASM7:Symbolnotpreviouslydefined(start)

TheerrorfilewillcontainMPASMassemblererrors,warningsandmessages.

HexFileFormats(.hex,.hxl,.hxh)

MPASMAssembleriscapableofproducingdifferenthexfileformats.

FormatName FormatType FileExtension UseIntelHexFormat INHX8M .HEX forstandardprogrammersIntelSplitHexFormat INHX8S .HXL,.HXH forodd/evenROMprogrammersIntelHex32Format INHX32 .HEX for16-bitcoreprogrammers

IntelHexFormat

Thisformatproducesone8-bithexfilewithalowbyte,highbytecombination.Sinceeachaddresscanonlycontain8bitsinthisformat,alladdressesaredoubled.ThisfileformatisusefulfortransferringPICmicroMCUseriescodetoPROMATEII,PICSTARTPlusandthirdpartyPICmicroMCUprogrammers.

Eachdatarecordbeginswitha9-characterprefixandendswitha2-characterchecksum.Eachrecordhasthefollowingformat:

:BBAAAATTHHHH....HHHCC

where:

BB-isatwodigithexadecimalbytecountrepresentingthenumberofdatabytesthatwillappearontheline.

AAAA-isafourdigithexadecimaladdressrepresentingthestartingaddressofthedatarecord.

TT-isatwodigitrecordtyperecordtypethatwillalwaysbe'00'exceptfortheend-of-filerecord,whichwillbe'01'.

HH-isatwodigithexadecimaldatabyte,presentedinlow-byte/high-bytecombinations.

CC-isatwodigithexadecimalchecksumthatisthetwo'scomplementofthesumofallprecedingbytesintherecord.

Example

<file_name>.HEX:1000000000000000000000000000000000000000F0:0400100000000000EC:100032000000280040006800A800E800C80028016D:100042006801A9018901EA01280208026A02BF02C5:10005200E002E80228036803BF03E803C8030804B8:1000620008040804030443050306E807E807FF0839:06007200FF08FF08190A57:00000001FF

IntelSplitHexFormat

Thesplit8-bitfileformatproducestwooutputfiles:.HXLand.HXH.Theformatisthesameasthenormal8-bitformat,exceptthatthelowbytesofthedatawordarestoredinthe.HXLfile,andthehighbytesofthedatawordarestoredinthe.HXHfile,andtheaddressesaredividedbytwo.Thisisusedtoprogram16-bitwordsintopairsof8-bitEPROMs,onefileforLowByte,onefileforHighByte.

Example

<file_name>.HXL

:0A0000000000000000000000000000F6:1000190000284068A8E8C82868A989EA28086ABFAA:10002900E0E82868BFE8C8080808034303E8E8FFD0:03003900FFFF19AD:00000001FF<file_name>.HXH:0A0000000000000000000000000000F6:1000190000000000000000010101010102020202CA:100029000202030303030304040404050607070883:0300390008080AAA:00000001FF

IntelHex32Format

Theextended32-bitaddresshexformatissimilartothehex8format,exceptthattheextendedlinearaddressrecordisoutputalsotoestablishtheupper16bitsofthedataaddress.Thisismainlyusedfor16-bitcoredevicessincetheiraddressableprogrammemoryexceeds32kwords.

Eachdatarecordbeginswitha9-characterprefixandendswitha2-characterchecksum.Eachrecordhasthefollowingformat:

:BBAAAATTHHHH....HHHCC

where:

BB-isatwodigithexadecimalbytecountrepresentingthenumberofdatabytesthatwillappearontheline.

AAAA-isafourdigithexadecimaladdressrepresentingthestartingaddressofthedatarecord.

TT-isatwodigitrecordtype:

00-Datarecord



01-EndofFilerecord

02-Segmentaddressrecord

04-Linearaddressrecord

HH-isatwodigithexadecimaldatabyte,presentedinlowbyte,highbytecombinations.

CC-isatwodigithexadecimalchecksumthatisthetwo'scomplementofthesumofallprecedingbytesintherecord.

SymbolandDebugFile(.cod)

ACODfileisusedbyMPLABIDEtodebugcode.TheCODfilename,includingthepath,hasa63characterlimit.MPASMassemblerandMPLINKlinkercangenerateaCODfile.

ObjectFile(.o)

Objectfilesaretherelocatablecodeproducedfromsourcefiles.

MPASMassemblerassemblessourcefilesintoobjectfiles.

MPLINKlinkercombinesobjectfilesandlibraryfiles,accordingtoalinkerscript,intoasingleoutputfile.MPLIBlibrariancombinesseveralobjectfilesintoasinglelibrary

file.





AssemblerInstallation

WhenMPLABIDEisinstalled,thewindowedversionofMPASMassemblerisalsoinstalled.YoumayobtaintheMPLABIDEsoftwareeitherfromthelatestMPLABIDECD-ROMorfromourwebsite.

Actually,therearetwoversionsofMPASMassembler:

aWindowsversion,MPASMWIN.EXE(Recommended)

aDOSversion,MPASM.EXE,forDOS5.0orgreater

AvailablefreewithMPLABIDE

MPASMWIN.EXEhasaWindowsshellinterface.MPASMWIN.EXEmaybeusedwithWindows95/98/ME,WindowsNT/2000orWindowsXP.YoucanusethisversionwithMPLABIDE(recommended)orstand-alone.

AvailablefreewithMPLABC1Xcompilers

MPASM.EXEhasacommandlineinterface.MPASM.EXEmaybeusedwithDOSoraDOSwindowinWindows3.x,Windows95/98/ME,WindowsNT/2000orWindowsXP.YoucanuseitwithMPLABIDE,thoughMPASMWIN.EXEisrecommended.





AssemblerUsagewithMPLABIDE

HowtouseMPASMassemblerwithMPLABIDEv6.xxandlaterisdiscussedhere.Thewindowsversion(mpasmwin.exe)oftheassemblershouldbeusedwithMPLABIDE.

MPLABIDEInterface

MPLABIDEProjectsProjectandAssemblerSetup



MPLABIDEInterface

MPASMassemblermaybeusedwiththeMPLABIDEintegrateddevelopmentenvironmenttoprovideGUIdevelopmentofyourapplication.InordertouseMPASMassemblerwithMPLABIDE,youmustfirstinstallMPLABIDE.Thelatestversionofthisfreesoftwareisavailableatourwebsite(http://www.microchip.com)orfromanysalesoffice(backcover).WhenyouinstallMPLABIDE,youwillbeinstallingMPASMassembleraswell.

OnceMPLABIDEisinstalledonyourPC,checkthesettingsbelowtoensurethattheassemberisinstalledproperlyasalanguagetool.

1. FromtheMPLABIDEmenubar,selectProject>SetLanguageToolLocationstoopenadialogtoset/checklanguagetoolexecutablelocation.

FIGURE:MPASMASSEMBLEREXECUTABLELOCATION



1. Inthedialog,underRegisteredTools,select"MicrochipMPASMToolsuite".Clickthe"+"toexpand.

SelectExecutables.Clickthe"+"toexpand.

SelectMPASMAssembler(mpasmwin.exe).UnderLocation,apathtothempasmwin.exefileshouldbedisplayed.Ifnopathisdisplayed,enteroneorbrowsetothelocationofthisfile.Bydefault,itislocatedat:

C:\ProgramFiles\MPLABIDE\MCHIP_Tools\mpasmwin.exe

ClickOK.



MPLABIDEProjects

AprojectinMPLABIDEisagroupoffilesneededtobuildanapplication,alongwiththeirassociationstovariousbuildtools.BelowagenericMPLABIDEProjectusingtheMPASMassemblertoolisshown.

FIGURE:PROJECTRELATIONSHIPS

InthisMPLABIDEProject,anassemblysourcefile(prog.asm)isshownwithitsassociatedassembler(MPASMassembler).MPLABIDEwillusethisinformationtogeneratetheobjectfileprog.oforinputintoMPLINKlinker.

TheCsourcefilemain.cisalsoshownwithitsassociatedMPLABC1Xcompiler.MPLABIDEwillusethisinformationtogenerateanobjectfile(main.o)forinputintothelinker(MPLINKlinker).SeeeithertheMPLABC17CompilerUser'sGuide(DS51290)forPIC17CXXXdevicesortheMPLABC18CompilerUser'sGuide(DS51288)forPIC18XXXXXdevicesformoreinformationonusingthesecompilers.

Inaddition,precompiledobjectfiles(precomp.o)maybeincludedinaproject,withnoassociatedtoolrequired.Typesofprecompiledobjectfilesthataregenerallyrequiredinaprojectare:

Startupcode

InitializationcodeInterruptserviceroutinesRegisterdefinitions

Precompiledobjectfilesareoftendeviceand/ormemorymodeldependent.FormoreinformationonavailableMicrochipprecompiledobjectfiles,seeeithertheMPLABC17CompilerLibraries(DS51296)forPIC17CXXXdevicesortheMPLABC18CompilerLibraries(DS51297)forPIC18XXXXXdevices.

Somelibraryfiles(math.lib)areavailablewiththecompiler.Othersmaybebuiltoutsidetheprojectusingthelibrariantool(MPLIBlibrarian).SeetheMPLIBObjectLibrariansectionlaterinthismanualformoreinformationonusingthelibrarian.FormoreinformationonavailableMicrochiplibraries,seetheMPLABC1Xlibrarydocumentspreviouslymentioned.



Theobjectfiles,alongwithlibraryfilesandalinkerscriptfile(device.lkr)areusedtogeneratetheprojectoutputfilesviathelinker(MPLINKlinker).SeetheMPLINKObjectLinkersectionlaterinthismanualformoreinformationonlinkerscriptfilesandusingthelinker.

ThemainoutputfilegeneratedbyMPLINKlinkeristheHexfile(prog.hex),usedbysimulators(MPLABSIM),emulators(MPLABICE2000)andprogrammers(PROMATEIIandPICSTARTPlus).Theotheroutputfilesare:

COFFfile(.out).IntermediatefileusedbyMPLINKlinkertogenerateCodefile,Hexfile,andListingfile.

Codefile(.cod).DebugfileusedbyMPLABIDE.Listingfile(.lst).Originalsourcecode,side-by-sidewithfinal

binarycode.Mapfile(.map).Showsthememorylayoutafterlinking.

Indicatesusedandunusedmemoryregions.





ProjectandAssemblerSetup

TosetupanMPLABIDEprojectforthefirsttime,itisadvisabletousethebuilt-inProjectWizard(Project>ProjectWizard.)Inthiswizard,youwillbeabletoselectalanguagetoolsuitethatusesMPASMassembler,e.g.,theMicrochipMPASMToolsuite.Formoreonthewizard,andMPLABIDEprojects,seeMPLABIDEdocumentation.

Onceyouhaveaprojectsetup,youmaythensetuppropertiesofMPASMassemblerinMPLABIDE.

1. FromtheMPLABIDEmenubar,selectProject>BuildOptions>Projecttoopenadialogtoset/checkprojectbuildoptions.

Note:MPASMassemblerdoesnotrecognizeincludepathinformationspecifiedinMPLABIDE.

ClickontheMPASMAssemblertabandenter/changeassemblersettings.





AssemblerUsagewithoutMPLABIDE

HowtouseMPASMassemblerwithoutMPLABIDEisdiscussedhere.

Thecommand-lineversion(mpasm.exe)mayberunfromthecommandlineoracommandshell.Thewindowsversion(mpasmwin.exe)maybefromthecommandlineoraWindowsshell.

CommandLineInterface

CommandShellInterfaceWindowsShellInterfaceTroubleshooting




MPASMassemblercanbeinvokedthroughthecommandlineinterface(commandprompt)asfollows:

mpasmwin[/<Option>[/<Option>...]][<filename>]

or

mpasm[/<Option>[/<Option>...]][<filename>]

where

/<Option>-referstooneofthecommandlineoptions

<filename>-isthefilebeingassembled

Forexample,iftest.asmexistsinthecurrentdirectory,itcanbeassembledwithfollowingcommand:

mpasmwin/e/ltest

Theassemblerdefaults(notedbelow)canbeoverriddenwithoptions:

Option Result/<option> Enablestheoption

/<option>+ Enablestheoption

/<option>- Disablestheoption

/<option><filename>

Ifappropriate,enablestheoptionanddirectstheoutputtothespecifiedfile

Ifthesourcefilenameisomitted,theappropriateshellinterfaceisinvoked,i.e.,

mpasmwin-aWindowsinterfaceisdisplayed,whichincludesaHelpbutton

mpasm-theassemblerhelppanelisdisplayed(sameasmpasm/?)

Option Default Description? N/A Displaystheassemblerhelppanel(mpasm.exe).

a INHX8M Generateabsolute.codand.hexoutputdirectlyfromassembler;/a<hex-format>,where<hex-format>isoneof[INHX8M|INHX8S|INHX32].

c On Enables/Disablescasesensitivity.

d N/A Defineatextstringsubstitution;/d<label>[=<value>].

e On

Enable/Disable/SetPathforerrorfile./eEnable/e+Enable/e-Disable/e<path>error.fileEnables/setspath

h N/A Displaystheassemblerhelppanel.

l On

Enable/Disable/SetPathforlistfile/lEnable/l+Enable/l-Disable/l<path>list.fileEnables/setspath

m On Enable/Disablemacroexpansion.

o Off

Enable/Disable/SetPathforobjectfile./oEnable/o+Enable/o-Disable/o<path>object.fileEnables/setspath

p None Settheprocessortype;/p<processor_type>,where<processor_type>isaPICmicroMCUdevice,e.g.,PIC16C54.

q Off Enable/Disablequietmode(suppressscreenoutput).

r Hex Definesdefaultradix;/r<radix>,where<radix>isoneof[HEX|DEC|OCT].

t 8 Listfiletabsize;/t<size>.

w 0

Setmessagelevel;/w<value>,where<value>isoneof[0|1|2].0allmessages1errorsandwarnings2errorsonly

x Off

Enable/Disable/SetPathforcrossreferencefile./xEnable/x+Enable/x-Disable/x<path>xref.fileEnables/setspath

y Disabled

Enable/Disableextendedinstructionset./yEnable/y+Enable/y-DisableCanonlybeenabledforprocessorswhichsupporttheextendedinstructionsetand



thegenericprocessorPIC18CXX./y-overridesLISTPE=<type>directive.(Specifyprocessortypeandenableextendedinstructionset.)



CommandShellInterface

TheMPASMassemblercommandshellinterfacedisplaysascreeninTextGraphicsmode.Itisinvokedbyexecutingmpasm.exeinWindowsExplorer.

Onthisscreen,youcanfillinthenameofthesourcefileyouwanttoassembleandotherinformation.

FIGURE:TEXTGRAPHICSMODEDISPLAY

SourceFile

Typethenameofyoursourcefile.ThenamecanincludeaDOSpathandwildcards.Ifyouusewildcards(oneof*or?),alistofallmatchingfilesisdisplayedforyoutoselectfrom.Toautomaticallyenter*.ASMinthisfield,press<TAB>.

ProcessorType

Ifyoudonotspecifytheprocessorinyoursourcefile,usethisfieldtoselecttheprocessor.Enterthefieldbyusingthearrowkeys,thentogglethroughtheprocessorsbypressing<RET>.

ErrorFile

Anerrorfile(<sourcename>.err)iscreatedbydefault.Toturntheerrorfileoff,usethe<Ã>tomovetotheYESandpress<RET>tochangeittoNO.Theerrorfilenamecanbechangedbypressingthe<TAB>keytomovetotheshadedareaandtypinganewname.Wildcardsarenotallowedintheerrorfilename.

CrossReferenceFile

Acrossreferencefile(<sourcename>.xrf)isnotgeneratedbydefault.Tocreateacrossreferencefile,usethekeyboardarrowkeystomovetotheNOandpress<RET>tochangeittoYES.Thecrossreferencefilenamecanbechangedbypressingthe<TAB>keytomovetotheshadedareaandtypinganewname.Wildcardsarenotallowedinthecrossreferencefilename.

ListingFile



Alistingfile(<sourcename>.lst)iscreatedbydefault.Toturnthelistingfileoff,usethe<Ã>tomovetotheYESandpress<RET>tochangeittoNO.Thelistingfilenamecanbechangedbypressingthe<TAB>keytomovetotheshadedareaandtypinganewname.Wildcardsarenotallowedinthelistingfilename.

HEXDumpType

Setthisvaluetogeneratethedesiredhexfileformat.Changingthisvalueisaccomplishedbymovingtothefieldwiththe<Ã>keyandpressingthe<RET>keytoscrollthroughtheavailableoptions.Tochangethehexfilename,pressthe<TAB>keytomovetheshadedarea,andtypeinthenewname.

AssembletoObjectFile

Enablingthisoptionwillgeneratetherelocatableobjectcodethatcanbeinputtothelinkerandsuppressgenerationofthehexfile.Thefilenamemaybemodifiedinthesamemannerastheerrorfile.



WindowsShellInterface

MPASMassemblerforWindowsprovidesagraphicalinterfaceforsettingassembleroptions.Itisinvokedbyexecutingmpasmwin.exeinWindowsExplorer.

FIGURE:MPASMASSEMBLERWINDOWSSHELLINTERFACE



SelectasourcefilebytypinginthenameorusingtheBrowsebutton.Setthevariousoptionsasdescribedbelow.ThenclickAssembletoassemblethesourcefile.

Note:WhenMPASMassemblerforWindowsisinvokedthroughMPLABIDE,theoptionsscreenisnotavailable.RefertotheMakeSetupoptionintheMPLABIDEUser'sGuideforselectingassemblyoptionsinMPLABIDE.

Option UsageRadix Overrideanysourcefileradixsettings.WarningLevel Overrideanysourcefilemessagelevelsettings.HexOutput Overrideanysourcefilehexfileformatsettings.GeneratedFiles Enable/disablevariousoutputfiles.CaseSensitivity Enable/disablecasesensitivity.MacroExpansion Overrideanysourcefilemacroexpansionsettings.Processor Overrideanysourcefileprocessorsettings.TabSize Setthelistfiletabsize.

ExtraOptions Anyadditionalcommandlineoptions.SeeCommandLineInterfaceformoredetails.

SaveSettingsonExit

Savethesesettingsinmplab.ini.Theywillbeusedthenexttimeyourunmpasmwin.exe.

ExtendedMode Enableextendedmode.



Troubleshooting

Ifyouareusingmpasm.exeandgetamessagesayingthatyouhaverunoutofenvironmentspace,useMicrosoftWindowsInternetExplorertoselectthempasm.exefileintheMPLABIDEinstallationdirectory,andclickontherightmousebuttontobringupthePropertiesdialog.

FIGURE:PROPERTIESDIALOG-MPASM.EXE



IncreasethesizeoftheInitialEnvironment.Usuallyasettingof2048willsuffice,butifyouhavealotofapplicationsthatsetvariablesandaddtoyourpathstatementinyourAUTOEXEC.BATfile,youmayneedtomakeitlarger.



Directives

Directivesareassemblercommandsthatappearinthesourcecodebutarenottranslateddirectlyintoopcodes.Theyareusedtocontroltheassembler:itsinput,output,anddataallocation.

Manyoftheassemblerdirectiveshavealternatenamesandformats.ThesemayexisttoprovidebackwardcompatibilitywithpreviousassemblersfromMicrochipandtobecompatiblewithindividualprogrammingpractices.Ifportablecodeisdesired,itisrecommendedthatprogramsbewrittenusingthespecificationscontainedhere.

Note:AlthoughMPASMassemblerisoftenusedwithMPLINKobjectlinker,MPASMassemblerdirectivesarenotsupportedbyMPLINKlinker.SeeMPLINKobjectlinkerdocumentationformoreinformationonlinkeroptionstocontrollistingandhexfileoutput.

Directivesdiscussedare:

Note:Directivesarenotcase-sensitive,e.g.,cblockmaybeexecutedasCBLOCK,cblock,Cblock,etc

__BADRAM-IdentifyUnimplementedRAM

__BADROM-IdentifyUnimplementedROM__CONFIG-SetProcessorConfigurationBits__IDLOCS-SetProcessorIDLocations__MAXRAM-DefineMaximumRAMLocation__MAXROM-DefineMaximumROMLocation#DEFINE-DefineaTextSubstitutionLabel#INCLUDE-IncludeAdditionalSourceFile

#UNDEFINE-DeleteaSubstitutionLabelBANKISEL-GenerateIndirectBankSelectingCodeBANKSEL-GenerateBankSelectingCodeCBLOCK-DefineaBlockofConstantsCODE-BeginanObjectFileCodeSectionCODE_PACK-BeginanObjectFilePackedCodeSectionCONSTANT-DeclareSymbolConstantDA-StoreStringsinProgramMemoryData-CreateNumericandTextDataDB-DeclareDataofOneByteDE-DeclareEEPROMDataByteDT-DefineTableDW-DeclareDataofOneWordELSE-BeginAlternativeAssemblyBlocktoIFEND-EndProgramBlockENDC-EndanAutomaticConstantBlockENDIF-EndConditionalAssemblyBlockENDM-EndaMacroDefinitionENDW-EndaWhileLoopEQU-DefineanAssemblerConstantERROR-IssueanErrorMessageERRORLEVEL-SetMessageLevelEXITM-ExitfromaMacroEXPAND-ExpandMacroListingEXTERN-DeclareanExternallyDefinedLabelFILL-SpecifyMemoryFillValueGLOBAL-ExportaLabelIDATA-BeginanObjectFileInitializedDataSection

IF-BeginConditionallyAssembledCodeBlockIFDEF-ExecuteIfSymbolhasBeenDefinedIFNDEF-ExecuteIfSymbolhasnotBeenDefinedLIST-ListingOptionsLOCAL-DeclareLocalMacroVariableMACRO-DeclareMacroDefinitionMESSG-CreateUserDefinedMessageNOEXPAND-TurnoffMacroExpansionNOLIST-TurnoffListingOutputORG-SetProgramOriginPAGE-InsertListingPageEjectPAGESEL-GeneratePageSelectingCodePROCESSOR-SetProcessorTypeRADIX-SpecifyDefaultRadixRES-ReserveMemorySET-DefineanAssemblerVariableSPACE-InsertBlankListingLinesSUBTITLE-SpecifyProgramSubtitleTITLE-SpecifyProgramTitleUDATA-BeginanObjectFileUninitializedDataSectionUDATA_ACS-BeginanObjectFileAccessUninitializedData

SectionUDATA_OVR-BeginanObjectFileOverlayedUninitializedData

SectionUDATA_SHR-BeginanObjectFileSharedUninitializedData

SectionVARIABLE-DeclareSymbolVariableWHILE-PerformLoopWhileConditionisTrue





__BADRAM-IdentifyUnimplementedRAM

Note:badramisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadibilityonly.

Syntax

__badram<expr>[-<expr>][,<expr>[-<expr>]]

Description

The__maxramand__badramdirectivestogetherflagaccessestounimplementedregisters.__badramdefinesthelocationsofinvalidRAMaddresses.Thisdirectiveisdesignedforusewiththe__maxramdirective.A__maxramdirectivemustproceedany__badramdirective.Each<expr>mustbelessthanorequaltothevaluespecifiedby__maxram.Oncethe__maxramdirectiveisused,strictRAMaddresscheckingisenabled,usingtheRAMmapspecifiedby__badram.Tospecifyarangeofinvalidlocations,usethesyntax<minloc>-<maxloc>.

Example

Seetheexamplefor__maxram.

SeeAlso

__MAXRAM





__BADROM-IdentifyUnimplementedROM

Note:badromisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadibilityonly.

Syntax

__badrom<expr>[-<expr>][,<expr>[-<expr>]]

Description

The__maxromand__badromdirectivestogetherflagaccessestounimplementedregisters.__badromdefinesthelocationsofinvalidROMaddresses.Thisdirectiveisdesignedforusewiththe__maxromdirective.A__maxromdirectivemustproceedany__badromdirective.Each<expr>mustbelessthanorequaltothevaluespecifiedby__maxrom.Oncethe__maxromdirectiveisused,strictROMaddresscheckingisenabled,usingtheROMmapspecifiedby__badrom.Tospecifyarangeofinvalidlocations,usethesyntax<minloc>-<maxloc>.

Specifically,awarningwillberaisedinthefollowingcircumstances:

thetargetofaGOTOorCALLinstructionisevaluatedbytheassemblertoaconstant,andfallsinabadROMregion

thetargetofanLGOTOorLCALLpsuedo-opisevaluatedbytheassemblertoaconstant,andfallsinabadROMregion

a.hexfileisbeinggenerated,andpartofaninstructionfallsinabadROMregion



Example

Seetheexamplefor__maxrom.

SeeAlso

__MAXROM



__CONFIG-SetProcessorConfigurationBits

Note:configisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadabilityonly.

Syntax

__config<expr>OR__config<addr>,<expr>

Description

Setstheprocessor'sconfigurationbitstothevaluedescribedby<expr>.ForPIC18CXXXdevices,theaddressofavalidconfigurationbytemustalsobespecifiedby<addr>.RefertoindividualPICmicromicrocontrollerdatasheetsforadescriptionoftheconfigurationbits.

Beforethisdirectiveisused,theprocessormustbedeclaredthroughthecommandline,thelistdirective,ortheprocessordirective.IfthisdirectiveisusedwiththePIC17CXXXfamily,theHexfileoutputformatmustbesettoINHX32throughthecommandlineorthelistdirective.

Examples

example1:listp=17c42,f=INHX32;defineprocessorandselectoutputformat__configH'FFFF';defaultconfigurationbits

example2:listp=16f877a;listdirectivetodefineprocessor



#include<p16f877a.inc>;includefilewithconfigbitdefinitions__config_HS_OSC&_WDT_OFF&_LVP_OFF;SetoscillatortoHS,;watchdogtimeoff,;low-voltageprog.off

example3:listp=18f8720;listdirectivetodefineprocessor#include<p18f8720.inc>;includefilewithconfigbitdefinitions__CONFIG_CONFIG1H,_OSCS_OFF_1H&_HS_OSC_1H;Setoscinfo__CONFIG_CONFIG2L,_BOR_OFF_2L&_PWRT_OFF_2L;Setpowerinfo

SeeAlso

__IDLOCSLISTPROCESSOR



__IDLOCS-SetProcessorIDLocations

Note:idlocsisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadibilityonly.

Syntax

__idlocs<expr>or__idlocs<expr1>,<expr2>

Description

ForPIC12CXXXandPIC16CXXXdevices,__idlocssetsthefourIDlocationstothehexadecimalvalueof<expr>.ForPIC18CXXXdevices,__idlocssetsthetwo-bytedeviceID<expr1>tothehexadecimalvalueof<expr2>.ThisdirectiveisnotvalidforthePIC17CXXXfamily.

Forexample,if<expr>evaluatesto1AF,thefirst(lowestaddress)IDlocationiszero,thesecondisone,thethirdisten,andthefourthisfifteen.

Beforethisdirectiveisused,theprocessormustbedeclaredthroughthecommandline,thelistdirective,ortheprocessordirective.

Example

__idlocsH'1234'

SeeAlso

__CONFIGLISTPROCESSOR





__MAXRAM-DefineMaximumRAMLocation

Note:maxramisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadibilityonly.

Syntax

__maxram<expr>

Description

The__maxramand__badramdirectivestogetherflagaccessestounimplementedregisters.__maxramdefinestheabsolutemaximumvalidRAMaddressandinitializesthemapofvalidRAMaddressestoalladdressesvalidatandbelow<expr>.<expr>mustbegreaterthanorequaltothemaximumpage0RAMaddressandlessthan1000H.Thisdirectiveisdesignedforusewiththe__badramdirective.Oncethe__maxramdirectiveisused,strictRAMaddresscheckingisenabled,usingtheRAMmapspecifiedby__badram.

__maxramcanbeusedmorethanonceinasourcefile.EachuseredefinesthemaximumvalidRAMaddressandresetstheRAMmaptoalllocations.

Example

listp=16c622__maxramH'0BF'__badramH'07'-H'09',H'0D'-H'1E'__badramH'87'-H'89',H'8D',H'8F'-H'9E'



movwfH'07';GeneratesinvalidRAMwarningmovwfH'87';GeneratesinvalidRAMwarning;andtruncationmessage

SeeAlso

__BADRAM



__MAXROM-DefineMaximumROMLocation

Note:maxromisprecededbytwounderlinecharacters,withnospaceinbetweenthesecharacters.Aspaceisaddedhereforreadibilityonly.

Syntax

__maxrom<expr>

Description

The__maxromand__badromdirectivestogetherflagaccessestounimplementedregisters.__maxromdefinestheabsolutemaximumvalidROMaddressandinitializesthemapofvalidROMaddressestoalladdressesvalidatandbelow<expr>.<expr>mustbegreaterthanorequaltothemaximumROMaddressofthetargetdevice.Thisdirectiveisdesignedforusewiththe__badromdirective.Oncethe__maxromdirectiveisused,strictROMaddresscheckingisenabled,usingtheROMmapspecifiedby__badrom.

__maxromcanbeusedmorethanonceinasourcefile.EachuseredefinesthemaximumvalidROMaddressandresetstheROMmaptoalllocations.

Example

listp=12c508__maxrom0x1FF__badrom0x2-0x4,0xAorg0x5



goto0x2;generatesawarningcall0x3;generatesawarningorg0xAmovlw5;generatesawarning

SeeAlso

__BADROM



#DEFINE-DefineaTextSubstitutionLabel

Syntax

#define<name>[<string>]

Description

Thisdirectivedefinesatextsubstitutionstring.Wherever<name>isencounteredintheassemblycode,<string>willbesubstituted.

Usingthedirectivewithno<string>causesadefinitionof<name>tobenotedinternallyandmaybetestedforusingtheifdefdirective.

ThisdirectiveemulatestheANSI'C'standardfor#define.SymbolsdefinedwiththismethodarenotavailableforviewingusingMPLABIDE.

Example

#definelength20#definecontrol0x19,7#defineposition(X,Y,Z)(Y-(2*Z+X))::test_labeldwposition(1,length,512)bsfcontrol;setbit7inf19

SeeAlso



#UNDEFINE#INCLUDEIFDEFIFNDEF





#INCLUDE-IncludeAdditionalSourceFile

Syntax

#include<<include_file>>#include"<include_file>"

Description

Thespecifiedfileisreadinassourcecode.Theeffectisthesameasiftheentiretextoftheincludedfilewereinsertedintothefileatthelocationoftheincludestatement.Uponend-of-file,sourcecodeassemblywillresumefromtheoriginalsourcefile.Upto5levelsofnestingarepermitted.Upto255includefilesareallowed.

<include_file>maybeenclosedinquotesoranglebrackets.Ifafullyqualifiedpathisspecified,onlythatpathwillbesearched.Otherwise,thesearchorderis:currentworkingdirectory,sourcefiledirectory,MPASMassemblerexecutabledirectory.

Example

#include"c:\sys\sysdefs.inc";systemdefs#include<regs.h>;registerdefs

SeeAlso

#DEFINE#UNDEFINE





#UNDEFINE-DeleteaSubstitutionLabel

Syntax

#undefine<label>

Description

<label>isanidentifierpreviouslydefinedwiththe#definedirective.ItmustbeavalidMPASMassemblerlabel.Thesymbolnamedisremovedfromthesymboltable.

Example

#definelength20:#undefinelength

SeeAlso

#DEFINE#INCLUDEIFDEFIFNDEF



BANKISEL-GenerateIndirectBankSelectingCode

Syntax

bankisel<label>

Description

Forusewhengeneratinganobjectfile.Thisdirectiveisaninstructiontothelinkertogeneratetheappropriatebankselectingcodeforanindirectaccessoftheaddressspecifiedby<label>.Onlyone<label>shouldbespecified.Nooperationscanbeperformedon<label>.<label>musthavebeenpreviouslydefined.

Thelinkerwillgeneratetheappropriatebankselectingcode.For14-bitcoredevices,theappropriatebitset/clearinstructionontheIRPbitintheSTATUSregisterwillbegenerated.Forthe16-bitcoredevices,MOVLBorMOVLRwillbegenerated.Iftheusercancompletelyspecifytheindirectaddresswithouttheseinstructions,nocodewillbegenerated.

Formoreinformation,refertoRelocatableObjects.

Example

movlwVar1movwfFSRbankiselVar1:movwfINDF



SeeAlso

BANKSELPAGESEL



BANKSEL-GenerateBankSelectingCode

Syntax

banksel<label>

Description

Forusewhengeneratinganobjectfile.Thisdirectiveisaninstructiontothelinkertogeneratebankselectingcodetosetthebanktothebankcontainingthedesignated<label>.Onlyone<label>shouldbespecified.Nooperationscanbeperformedon<label>.<label>musthavebeenpreviouslydefined.

Thelinkerwillgeneratetheappropriatebankselectingcode.For12-bitcoredevices,theappropriatebitset/clearinstructionsontheFSRwillbegenerated.For14-bitdevices,bitset/clearinstructionsontheSTATUSregisterwillbegenerated.Forthe16-bitcoredevices,MOVLBorMOVLRwillbegenerated.Fortheenhanced16-bitcoredevices,MOVLBwillbegenerated.IfthedevicecontainsonlyonebankofRAM,noinstructionswillbegenerated.


Example

bankselVar1movwfVar1

SeeAlso

BANKISELPAGESEL





CBLOCK-DefineaBlockofConstants

Syntax

cblock[<expr>]<label>[:<increment>][,<label>[:<increment>]]endc

Description

Definealistofnamedconstants.Each<label>isassignedavalueofonehigherthantheprevious<label>.Thepurposeofthisdirectiveistoassignaddressoffsetstomanylabels.Thelistofnamesendwhenanendcdirectiveisencountered.

<expr>indicatesthestartingvalueforthefirstnameintheblock.Ifnoexpressionisfound,thefirstnamewillreceiveavalueonehigherthanthefinalnameinthepreviouscblock.Ifthefirstcblockinthesourcefilehasno<expr>,assignedvaluesstartwithzero.

If<increment>isspecified,thenthenext<label>isassignedthevalueof<increment>higherthantheprevious<label>.

Multiplenamesmaybegivenonaline,separatedbycommas.

cblockisusefulfordefiningconstantsinprogramanddatamemory.

Example

cblock0x20;name_1willbeassigned20name_1,name_2;name_2,21andsoon



name_3,name_4;name_4isassigned23.endccblock0x30TwoByteVar:0,TwoByteHigh,TwoByteLowQueue:QUEUE_SIZEQueueHead,QueueTailDouble1:2,Double2:2endc

SeeAlso

ENDC





CODE-BeginanObjectFileCodeSection

Syntax

[<label>]code[<ROMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofprogramcode.If<label>isnotspecified,thesectionisnamed.code.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.

Note:Twosectionsinthesamesourcefilemaynothavethesamename.


Example

RESETcodeH'01FF'gotoSTART

SeeAlso

EXTERNCODE_PACKGLOBALIDATAUDATAUDATA_ACSUDATA_OVRUDATA_SHR



CODE_PACK-BeginanObjectFilePackedCodeSection

Syntax

[<label>]code_pack[<ROMaddress>]

Description

Forusewhengeneratinganobjectfile.DeclaresthebeginningofasectionofprogramcodeorROMdatawhereapaddingbyteofzeroisnotappendedtoanoddnumberofbytes.If<label>isnotspecified,thesectionisnamed.code.Thestartingaddressisinitializedto<ROMaddress>orwillbeassignedatlinktimeifnoaddressisspecified.If<ROMaddress>isspecified,itmustbeword-aligned.

Note:Twosectionsinthesamesourcefilemaynothavethesamename


Note:ThisdirectiveisonlyavailableforthePIC18familyofdevices.

Example

00001LISTP=18Cxx0000200003packedcode_packH'1F0'0001F001020300004DB1,2,30001F3040500005DB4,50000600007paddedcode



0000000201000300008DB1,2,3000004050400009DB4,50001000011END

SeeAlso

EXTERNCODEGLOBALIDATAUDATAUDATA_ACSUDATA_OVRUDATA_SHR



MicrochipTechnologyInc.

CONSTANT-DeclareSymbolConstant

Syntax

constant<label>=<expr>[...,<label>=<expr>]

Description

CreatessymbolsforuseinMPASMassemblerexpressions.Constantsmaynotberesetafterhavingoncebeeninitialized,andtheexpressionmustbefullyresolvableatthetimeoftheassignment.Thisistheprincipaldifferencebetweensymbolsdeclaredasconstantandthosedeclaredasvariable,orcreatedbythesetdirective.Otherwise,constantsandvariablesmaybeusedinterchangeablyinexpressions.

Example

variableRecLength=64;SetDefault;RecLengthconstantBufLength=512;InitBufLength.;RecLengthmay.;beresetlater.;inRecLength=128.;constantMaxMem=RecLength+BufLength;CalcMaxMem

SeeAlso

SETVARIABLE

Microchip'sWebSiteVoice:(480)792-7200Fax:(480)899-9210






DA-StoreStringsinProgramMemory

Syntax

[<label>]da<expr>[,<expr2>,...,<exprn>]

Description

Generatesapacked14-bitnumberrepresentingtwo7-bitASCIIcharacters.ThisisusefulforstoringstringsinmemoryforthePICmicroMCUFlashROMdevices.

Examples

da"abcdef"

willput30E231E432E63380intoprogrammemory

da"12345678",0

willput18B219B41AB60000intoprogrammemory

da0xFFFF

willput0x3FFFintoprogrammemory



Data-CreateNumericandTextData

Syntax

[<label>]data<expr>,[,<expr>,...,<expr>][<label>]data"<text_string>"[,"<text_string>",...]

Description

Initializeoneormorewordsofprogrammemorywithdata.Thedatamaybeintheformofconstants,relocatableorexternallabels,orexpressionsofanyoftheabove.ThedatamayalsoconsistofASCIIcharacterstrings,<text_string>,enclosedinsinglequotesforonecharacterordoublequotesforstrings.Singlecharacteritemsareplacedintothelowbyteoftheword,whilestringsarepackedtwotoaword.Ifanoddnumberofcharactersaregiveninastring,thefinalbyteiszero.OnallfamiliesexceptthePIC18CXXX,thefirstcharacterisinthemostsignificantbyteoftheword.OnthePIC18CXXX,thefirstcharacterisintheleastsignificantbyteoftheword.

Whengeneratinganobjectfile,thisdirectivecanalsobeusedtodeclareinitializeddatavalues.Refertotheidatadirectiveformoreinformation.

Example

datareloc_label+10;constantsdata1,2,ext_label;constants,externalsdata"testing1,2,3";textstringdata'N';singlecharacterdatastart_of_program;relocatablelabel



SeeAlso

DBDEDTDWIDATA





DB-DeclareDataofOneByte

Syntax

[<label>]db<expr>[,<expr>,...,<expr>]

Description

Reserveprogrammemorywordswithpacked8-bitvalues.Multipleexpressionscontinuetofillbytesconsecutivelyuntiltheendofexpressions.Shouldtherebeanoddnumberofexpressions,thelastbytewillbezero.


Example

db't',0x0f,'e',0x0f,'s',0x0f,'t','\n'

SeeAlso

DATADEDTDWIDATA



DE-DeclareEEPROMDataByte

Syntax

[<label>]de<expr>[,<expr>,...,<expr>]

Description

AlthoughdesignedforinitializingEEPROMdataonthePIC16F8X,thedirectivecanbeusedatanylocationforanyprocessor.

PIC18XXXX

Reservememorywordbytesarepacked.

Whenusingde,makesuretospecifythestartofdatamemoryat0xF00000forusewithprogrammers.

OtherPICmicro's

Reservememorywordswith8-bitdata.Each<expr>mustevaluatetoan8-bitvalue.Theupperbitsoftheprogramwordarezeroes.Eachcharacterinastringisstoredinaseparateword.

Whenusingde,makesuretospecifythestartofdatamemoryat0x2100forusewithprogrammers.

Example

orgH'2100';InitializeEEPROMDatade"MyProgram,v1.0",0



SeeAlso

DATADBDTDW





DT-DefineTable

Syntax

[<label>]dt<expr>[,<expr>,...,<expr>]

Description

GeneratesaseriesofRETLWinstructions,oneinstructionforeach<expr>.Each<expr>mustbean8-bitvalue.EachcharacterinastringisstoredinitsownRETLWinstruction.

Example

dt"AMessage",0dtFirstValue,SecondValue,EndOfValues

SeeAlso

DATADBDEDW





DW-DeclareDataofOneWord

Syntax

[<label>]dw<expr>[,<expr>,...,<expr>]

Description

Reserveprogrammemorywordsfordata,initializingthatspacetospecificvalues.ForPIC18CXXXdevices,dwfunctionslikedb.Valuesarestoredintosuccessivememorylocationsandthelocationcounterisincrementedbyone.Expressionsmaybeliteralstringsandarestoredasdescribedinthedatadirective.


Example

dw39,"diagnostic39",(d_list*2+d_offset)dwdiagbase-1

SeeAlso

DATADBIDATA





ELSE-BeginAlternativeAssemblyBlocktoIF

Syntax

else

Description

Usedinconjunctionwithanifdirectivetoprovideanalternativepathofassemblycodeshouldtheifevaluatetofalse.elsemaybeusedinsidearegularprogramblockormacro.

Example

speedmacrorateifrate<50dwslowelsedwfastendifendm

SeeAlso

ENDIFIF





END-EndProgramBlock

Syntax

end

Description

Indicatestheendoftheprogram.

Example

listp=17c42:;executablecode:;end;endofinstructions

SeeAlso

ORG





ENDC-EndanAutomaticConstantBlock

Syntax

endc

Description

endcterminatestheendofacblocklist.Itmustbesuppliedtoterminatethelist.

SeeAlso

CBLOCK





ENDIF-EndConditionalAssemblyBlock

Syntax

endif

Description

Thisdirectivemarkstheendofaconditionalassemblyblock.endifmaybeusedinsidearegularprogramblockormacro.

SeeAlso

ELSEIF





ENDM-EndaMacroDefinition

Syntax

endm

Description

Terminatesamacrodefinitionbegunwithmacro.

Example

make_tablemacroarg1,arg2dwarg1,0;nullterminatetablenameresarg2;reservestorageendm

SeeAlso

MACROEXITM





ENDW-EndaWhileLoop

Syntax

endw

Description

endwterminatesawhileloop.Aslongastheconditionspecifiedbythewhiledirectiveremainstrue,thesourcecodebetweenthewhiledirectiveandtheendwdirectivewillberepeatedlyexpandedintheassemblysourcecodestream.Thisdirectivemaybeusedinsidearegularprogramblockormacro.

Example

SeetheexampleforWHILE.

SeeAlso

WHILE





EQU-DefineanAssemblerConstant

Syntax

<label>equ<expr>

Description

Thevalueof<expr>isassignedto<label>.

Example

fourequ4;assignedthenumericvalueof4tolabelfour

SeeAlso

SET





ERROR-IssueanErrorMessage

Syntax

error"<text_string>"

Description

<text_string>isprintedinaformatidenticaltoanyMPASMassemblererrormessage.<text_string>maybefrom1to80characters.

Example

error_checkingmacroarg1ifarg1>=55;ifargisoutofrangeerror"error_checking-01argoutofrange"endifendm

SeeAlso

MESSG





ERRORLEVEL-SetMessageLevel

Syntax

errorlevel{0|1|2|+<msgnum>|-<msgnum>}[,...]

Description

Setsthetypesofmessagesthatareprintedinthelistingfileanderrorfile.

Setting Affect0 Messages,warnings,anderrorsprinted

1 Warningsanderrorsprinted

2 Errorsprinted

-<msgnum> Inhibitsprintingofmessage<msgnum>+<msgnum> Enablesprintingofmessage<msgnum>

Errormessagescannotbedisabled.Thesettingof0,1,or2overridesindividualmessagedisablingorenabling.

Example

errorlevel1,-202

SeeAlso

LISTERROR





EXITM-ExitfromaMacro

Syntax

exitm

Description

Forceimmediatereturnfrommacroexpansionduringassembly.Theeffectisthesameasifanendmdirectivehadbeenencountered.

Example

testmacrofileregiffilereg==1;checkforvalidfileexitmelseerror"badfileassignment"endifendm

SeeAlso

ENDMMACRO





EXPAND-ExpandMacroListing

Syntax

expand

Description

Expandallmacrosinthelistingfile.Thisdirectiveisroughlyequivalenttothe/mMPASMassemblercommandlineoption,butmaybedisabledbytheoccurrenceofasubsequentnoexpand.

SeeAlso

MACRONOEXPAND



MicrochipTechnologyInc.Microchip'sWebSite

EXTERN-DeclareanExternallyDefinedLabel

Syntax

extern<label>[,<label>...]

Description

Forusewhengeneratinganobjectfile.Declaressymbolnamesthatmaybeusedinthecurrentmodulebutaredefinedasglobalinadifferentmodule.

Theexternstatementmustbeincludedbeforethe<label>isused.Atleastonelabelmustbespecifiedontheline.If<label>isdefinedinthecurrentmodule,MPASMassemblerwillgenerateaduplicatelabelerror.


Example

externFunction:callFunction

SeeAlso

GLOBALIDATAUDATAUDATA_ACSUDATA_OVRUDATA_SHR


Voice:(480)792-7200Fax:(480)899-9210



FILL-SpecifyMemoryFillValue

Syntax

[<label>]fill<expr>,<count>

Description

Generates<count>occurrencesoftheprogramwordorbyte(PIC18CXXXdevices),<expr>.Ifboundedbyparentheses,<expr>canbeanassemblerinstruction.

Examples

example1fill0x1009,5;fillwithaconstantfill(GOTORESET_VECTOR),NEXT_BLOCK-$

example2listp=18f252org0x12foogoto$org0x100fill(gotofoo),(h'8000'-$)/2;Divideby2for2-word;instructionsend

SeeAlso

DATADWORG





MicrochipTechnologyInc.Microchip'sWebSiteVoice:(480)792-7200

GLOBAL-ExportaLabel

Syntax

global<label>[,<label>...]

Description

Forusewhengeneratinganobjectfile.Declaressymbolnamesthataredefinedinthecurrentmoduleandshouldbeavailabletoothermodules.Atleastonelabelmustbespecifiedontheline.


Example

udataVar1res1Var2res1globalVar1,Var2codeAddThreeglobalAddThreeaddlw3return

SeeAlso

EXTERNIDATAUDATAUDATA_ACSUDATA_OVRUDATA_SHR


Fax:(480)899-9210Microchip'sE-mailAddress


IDATA-BeginanObjectFileInitializedDataSection

Syntax

[<label>]idata[<RAMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofinitializeddata.If<label>isnotspecified,thesectionisnamed.idata.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.Nocodecanbegeneratedinthissegment.

Thelinkerwillgeneratealook-uptableentryforeachbytespecifiedinanidatasection.Youmustthenlinkorincludetheappropriateinitializationcode.ExamplesofinitializationcodethatmaybeusedandmodifiedasneededmaybefoundwithMPLINKlinkersampleapplicationexamples.

Note:Thisdirectiveisnotavailablefor12-bitcoredevices.

Theres,dbanddwdirectivesmaybeusedtoreservespaceforvariables.reswillgenerateaninitialvalueofzero.dbwillinitializesuccessivebytesofRAM.dwwillinitializesuccessivebytesofRAM,onewordatatime,inlow-byte/high-byteorder.


Example



idataLimitLdw0LimitHdwD'300'GaindwD'5'Flagsdb0Stringdb'Hithere!'

SeeAlso

EXTERNGLOBALUDATAUDATA_ACSUDATA_OVRUDATA_SHR



IF-BeginConditionallyAssembledCodeBlock

Syntax

if<expr>

Description

Beginexecutionofaconditionalassemblyblock.If<expr>evaluatestotrue,thecodeimmediatelyfollowingtheifwillassemble.Otherwise,subsequentcodeisskippeduntilanelsedirectiveoranendifdirectiveisencountered.

AnexpressionthatevaluatestozeroisconsideredlogicallyFALSE.AnexpressionthatevaluatestoanyothervalueisconsideredlogicallyTRUE.Theifandwhiledirectivesoperateonthelogicalvalueofanexpression.ArelationalTRUEexpressionisguaranteedtoreturnanonzerovalue,FALSEavalueofzero.

if'smaybenestedupto16deep.

Example

ifversion==100;checkcurrentversionmovlw0x0amovwfio_1elsemovlw0x01amovwfio_2endif



SeeAlso

ELSEENDIF





IFDEF-ExecuteIfSymbolhasBeenDefined

Syntax

ifdef<label>

Description

If<label>hasbeenpreviouslydefined,usuallybyissuinga#definedirectiveorbysettingthevalueontheMPASMassemblercommandline,theconditionalpathistaken.Assemblywillcontinueuntilamatchingelseorendifdirectiveisencountered.

Example

#definetesting1;settesting"on":ifdeftesting<executetestcode>;thispathwouldbeexecuted.endif

SeeAlso

#DEFINE#UNDEFINEELSEENDIFIFNDEF



MicrochipTechnologyInc.Microchip'sWebSiteVoice:(480)792-7200

IFNDEF-ExecuteIfSymbolhasnotBeenDefined

Syntax

ifndef<label>

Description

If<label>hasnotbeenpreviouslydefined,orhasbeenundefinedbyissuingan#undefinedirective,thenthecodefollowingthedirectivewillbeassembled.Assemblywillbeenabledordisableduntilthenextmatchingelseorendifdirectiveisencountered.

Example

#definetesting1;settestingon:#undefinetesting1;settestingoffifndeftesting;ifnotintestingmode:;executethispathendifend;endofsource

SeeAlso

#DEFINE#UNDEFINEELSEENDIFIFDEF


Fax:(480)899-9210Microchip'sE-mailAddress


LIST-ListingOptions

Syntax

list[<list_option>,...,<list_option>]

Description

Occurringonalinebyitself,thelistdirectivehastheeffectofturninglistingoutputon,ifithadbeenpreviouslyturnedoff.Otherwise,oneofthefollowinglistoptionscanbesuppliedtocontroltheassemblyprocessorformatthelistingfile.

ListDirectiveOptions

Option Default Descriptionb=nnn 8 Settabspaces.

c=nnn 132 Setcolumnwidth.

f=<format> INHX8M Setthehexfileoutput.<format>canbeINHX32,INHX8M,orINHX8S.

free FIXED Usefree-formatparser.Providedforbackwardcompatibility.

fixed FIXED Usefixed-formatparser.

mm={ON|OFF} On Printmemorymapinlistfile.

n=nnn 60 Setlinesperpage.

p=<type> None Setprocessortype;forexample,PIC16C54.

pe=<type> None

Setprocessortypeandenableextendedinstructionset,forexample;LISTpe=PIC18F4620OnlyvalidwithprocessorswhichsupporttheextendedinstructionsetandthegenericprocessorPIC18CXX.Isoverriddenbycommand-lineoption/y-(disableextendedinstructionset).

r=<radix> hex Setdefaultradix:hex,dec,oct.

st={ON|OFF} On Printsymboltableinlistfile.

t={ON|OFF} Off Truncatelinesoflisting(otherwisewrap).



w={0|1|2}

0 Setthemessagelevel.SeeERRORLEVEL.

x={ON|OFF} On Turnmacroexpansiononoroff.

Note:Alllistoptionsareevaluatedasdecimalnumbers.

Example

listp=17c42,f=INHX32,r=DEC

SeeAlso

ERRORLEVELEXPANDNOEXPANDNOLISTPROCESSORRADIX



LOCAL-DeclareLocalMacroVariable

Syntax

local<label>[,<label>...]

Description

Declaresthatthespecifieddataelementsaretobeconsideredinlocalcontexttothemacro.<label>maybeidenticaltoanotherlabeldeclaredoutsidethemacrodefinition;therewillbenoconflictbetweenthetwo.

Ifthemacroiscalledrecursively,eachinvocationwillhaveitsownlocalcopy.

Example

<maincodesegment>::lenequ10;globalversionsizeequ20;notethatalocalvariable;maynowbecreatedandmodifiedtestmacrosizelocallen,label;locallenandlabellensetsize;modifylocallenlabelreslen;reservebufferlensetlen-20endm;endmacro

SeeAlso



ENDMMACRO



MACRO-DeclareMacroDefinition

Syntax

<label>macro[<arg>,...,<arg>]

Description

Amacroisasequenceofinstructionsthatcanbeinsertedintheassemblysourcecodebyusingasinglemacrocall.Themacromustfirstbedefined,thenitcanbereferredtoinsubsequentsourcecode.

Argumentsarereadinfromthesourceline,storedinalinkedlistandthencounted.Themaximumnumberofargumentswouldbethenumberofargumentsthatwouldfitonthesourceline,afterthelabelandmacroterms.Themaximumsourcelinelengthis200.

Amacrocancallanothermacro,ormaycallitselfrecursively.Themaximumnumberofnestedmacrocallsis16.

PleaserefertoMacroLanguageformoreinformation.

Example

Readmacrodevice,buffer,countmovlwdevicemovwfram_20movlwbuffer;bufferaddressmovwfram_21movlwcount;bytecountcallsys_21;readfilecallendm



SeeAlso

ENDMEXITMLOCAL





MESSG-CreateUserDefinedMessage

Syntax

messg"<message_text>"

Description

Causesaninformationalmessagetobeprintedinthelistingfile.Themessagetextcanbeupto80characters.Issuingamessgdirectivedoesnotsetanyerrorreturncodes.

Example

mssg_macromacromessg"mssg_macro-001invokedwithoutargument"endm

SeeAlso

ERROR





NOEXPAND-TurnoffMacroExpansion

Syntax

noexpand

Description

Turnsoffmacroexpansioninthelistingfile.

SeeAlso

EXPAND





NOLIST-TurnoffListingOutput

Syntax

nolist

Description

Turnofflistingfileoutput.

SeeAlso

LIST



ORG-SetProgramOrigin

Syntax

[<label>]org<expr>

Description

Settheprogramoriginforsubsequentcodeattheaddressdefinedin<expr>.If<label>isspecified,itwillbegiventhevalueofthe<expr>.Ifnoorgisspecified,codegenerationwillbeginataddresszero.

ForPIC18CXXXdevices,onlyeven<expr>valuesareallowed.

Whengeneratinganobjectfile,theorgdirectiveisinterpretedasintroducinganabsoluteCODEsectionwithaninternallygeneratedname.Forexample:

L1:org0x200

isinterpretedas:

.scnnameCODE0x200L1:

where.scnnameisgeneratedbytheassembler,andwillbedistinctfromeverynamepreviouslygeneratedinthiscontext.

Example

int_1org0x20;Vector20codegoeshereint_2orgint_1+0x10



;Vector30codegoeshere

SeeAlso

FILLRESEND





PAGE-InsertListingPageEject

Syntax

page

Description

Insertsapageejectintothelistingfile.

SeeAlso

LISTSUBTITLETITLE



PAGESEL-GeneratePageSelectingCode

Syntax

pagesel<label>

Description

Forusewhengeneratinganobjectfile.Aninstructiontothelinkertogeneratepageselectingcodetosetthepagebitstothepagecontainingthedesignated<label>.Onlyone<label>shouldbespecified.Nooperationscanbeperformedon<label>.<label>musthavebeenpreviouslydefined.

Thelinkerwillgeneratetheappropriatepageselectingcode.For12-bitcoredevices,theappropriatebitset/clearinstructionsontheSTATUSregisterwillbegenerated.For14-bitand16-bitcoredevices,MOVLWandMOVWFinstructionswillbegeneratedtomodifythePCLATH.Ifthedevicecontainsonlyonepageofprogrammemory,nocodewillbegenerated.

ForPIC18CXXXdevices,thiscommandwilldonothing.


Example

pageselGotoDestgotoGotoDest:pageselCallDestcallCallDest



SeeAlso

BANKISELBANKSEL





PROCESSOR-SetProcessorType

Syntax

processor<processor_type>

Description

Setstheprocessortypeto<processor_type>.

Example

processor16C54

SeeAlso

LIST





RADIX-SpecifyDefaultRadix

Syntax

radix<default_radix>

Description

Setsthedefaultradixfordataexpressions.Thedefaultradixishex.Validradixvaluesare:

hex-hexadecimal(base16)

dec-decimal(base10)oct-octal(base8)

Youmayalsospecifyaradixusingthelistdirective.Forspecifyingtheradixofconstants,seeNumericConstantsandRadix.

Example

radixdec

SeeAlso

LIST





RES-ReserveMemory

Syntax

[<label>]res<mem_units>

Description

Causesthememorylocationpointertobeadvancedfromitscurrentlocationbythevaluespecifiedin<mem_units>.Innon-relocatablecode,<label>isassumedtobeaprogrammemoryaddress.Inrelocatablecode(usingMPLINKlinker),rescanalsobeusedtoreservedatastorage.

Addresslocationsaredefinedinwordsfor12-,14-and16-bitPICmicroMCUs,andbytesforenhanced16-bitPICmicroMCUs.

Example

bufferres64;reserve64addresslocationsofstorage

SeeAlso

FILLORG





SET-DefineanAssemblerVariable

Syntax

<label>set<expr>

Description

<label>isassignedthevalueofthevalidMPASMassemblerexpressionspecifiedby<expr>.Thesetdirectiveisfunctionallyequivalenttotheequdirectiveexceptthatsetvaluesmaybesubsequentlyalteredbyothersetdirectives.

Example

areaset0widthset0x12lengthset0x14areasetlength*widthlengthsetlength+1

SeeAlso

EQUVARIABLE





SPACE-InsertBlankListingLines

Syntax

space<expr>

Description

Insert<expr>numberofblanklinesintothelistingfile.

Example

space3;Insertsthreeblanklines

SeeAlso

LIST





SUBTITLE-SpecifyProgramSubtitle

Syntax

subtitle"<sub_text>"

Description

<sub_text>isanASCIIstringenclosedindoublequotes,60charactersorlessinlength.Thisdirectiveestablishesasecondprogramheaderlineforuseasasubtitleinthelistingoutput.

Example

subtitle"diagnosticsection"

SeeAlso

LISTTITLE





TITLE-SpecifyProgramTitle

Syntax

title"<title_text>"

Description

<title_text>isaprintableASCIIstringenclosedindoublequotes.Itmustbe60charactersorless.Thisdirectiveestablishesthetexttobeusedinthetoplineofeachpageinthelistingfile.

Example

title"operationalcode,rev5.0"

SeeAlso

LISTSUBTITLE



MicrochipTechnologyInc.

UDATA-BeginanObjectFileUninitializedDataSection

Syntax

[<label>]udata[<RAMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofuninitializeddata.If<label>isnotspecified,thesectionisnamed.udata.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.Nocodecanbegeneratedinthissegment.Theresdirectiveshouldbeusedtoreservespacefordata.



Example

udataVar1res1Doubleres2

SeeAlso

EXTERNGLOBALIDATAUDATA_ACSUDATA_OVRUDATA_SHR

Microchip'sWebSiteVoice:(480)792-7200Fax:(480)899-9210




UDATA_ACS-BeginanObjectFileAccessUninitializedDataSection

Syntax

[<label>]udata_acs[<RAMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofaccessuninitializeddata.If<label>isnotspecified,thesectionisnamed.udata_acs.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.ThisdirectiveisusedtodeclarevariablesthatareallocatedinaccessRAMofPIC18CXXXdevices.Nocodecanbegeneratedinthissegment.Theresdirectiveshouldbeusedtoreservespacefordata.



Example

udata_acsVar1res1Doubleres2

SeeAlso

EXTERNGLOBALIDATAUDATAUDATA_OVRUDATA_SHR





UDATA_OVR-BeginanObjectFileOverlayedUninitializedDataSection

Syntax

[<label>]udata_ovr[<RAMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofoverlayeduninitializeddata.If<label>isnotspecified,thesectionisnamed.udata_ovr.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.Thespacedeclaredbythissectionisoverlayedbyallotherudata_ovrsectionsofthesamename.Itisanidealwayofdeclaringtemporaryvariablessinceitallowsmultiplevariablestobedeclaredatthesamememorylocation.Nocodecanbegeneratedinthissegment.Theresdirectiveshouldbeusedtoreservespacefordata.



Example

Tempsudata_ovrTemp1res1Temp2res1Temp3res1Tempsudata_ovrLongTemp1res2;thiswillbeavariableatthe



;samelocationasTemp1andTemp2LongTemp2res2;thiswillbeavariableatthe;samelocationasTemp3

SeeAlso

EXTERNGLOBALIDATAUDATAUDATA_ACSUDATA_SHR



UDATA_SHR-BeginanObjectFileSharedUninitializedDataSection

Syntax

[<label>]udata_shr[<RAMaddress>]

Description

Forusewhengeneratinganobjectfile.Declaresthebeginningofasectionofshareduninitializeddata.If<label>isnotspecified,thesectionisnamed.udata_shr.Thestartingaddressisinitializedtothespecifiedaddressorwillbeassignedatlinktimeifnoaddressisspecified.ThisdirectiveisusedtodeclarevariablesthatareallocatedinRAMthatissharedacrossallRAMbanks(i.e.unbankedRAM).Nocodecanbegeneratedinthissegment.Theresdirectiveshouldbeusedtoreservespacefordata.



Example

Tempsudata_shrTemp1res1Temp2res1Temp3res1

SeeAlso

EXTERNGLOBALIDATAUDATAUDATA_ACSUDATA_OVR







VARIABLE-DeclareSymbolVariable

Syntax

variable<label>[=<expr>][,<label>[=<expr>]...]

Description

CreatessymbolsforuseinMPASMassemblerexpressions.Variablesandconstantsmaybeusedinterchangeablyinexpressions.

Thevariabledirectivecreatesasymbolthatisfunctionallyequivalenttothosecreatedbythesetdirective.Thedifferenceisthatthevariabledirectivedoesnotrequirethatsymbolsbeinitializedwhentheyaredeclared.

Thevariablevaluescannotbeupdatedwithinanoperand.Youmustplacevariableassignments,increments,anddecrementsonseparatelines.

Example

Pleaserefertotheexamplegivenfortheconstantdirective.

SeeAlso

CONSTANTSET



WHILE-PerformLoopWhileConditionisTrue

Syntax

while<expr>:endw

Description

Thelinesbetweenthewhileandtheendwareassembledaslongas<expr>evaluatestoTRUE.AnexpressionthatevaluatestozeroisconsideredlogicallyFALSE.AnexpressionthatevaluatestoanyothervalueisconsideredlogicallyTRUE.ArelationalTRUEexpressionisguaranteedtoreturnanon-zerovalue;FALSEavalueofzero.

Awhileloopcancontainatmost100linesandberepeatedamaximumof256times.whileloopscanbenestedupto8deep.

Example

test_macmacrocountvariableii=0whilei<countmovlwii+=1endwendmstarttest_mac5



end

SeeAlso

ENDWIF



DirectiveUsage

HowtousetheMPASMassemblerdirectivelanguageisshownusingexamples.

Directivesareassemblercommandsthatappearinthesourcecodebutarenottranslateddirectlyintoopcodes.Theyareusedtocontroltheassembler:itsinput,output,anddataallocation.

Manyoftheassemblerdirectiveshavealternatenamesandformats.ThesemayexisttoprovidebackwardcompatibilitywithpreviousassemblersfromMicrochipandtobecompatiblewithindividualprogrammingpractices.Ifportablecodeisdesired,itisrecommendedthatprogramsbewrittenusingthespecificationscontainedwithinthisdocument.

Forareferencelistingofalldirectivesdiscussedinexampleshere,pleaseseeDirectives.

Note:AlthoughMPASMassemblerisoftenusedwithMPLINKobjectlinker,MPASMassemblerdirectivesarenotsupportedbyMPLINKlinker.SeeMPLINKobjectlinkerdocumentationformoreinformationonlinkeroptionstocontrollistingandhexfileoutput.

Therearesixbasictypesofdirectivesprovidedbytheassembler:

Note:Directivesarenotcase-sensitive,e.g.,cblockmaybeexecutedasCBLOCK,cblock,Cblock,etc.

ControlDirectives

ConditionalAssemblyDirectivesDataDirectivesListingDirectives



MacroDirectivesObjectFileDirectives

Foralldirectivetypes:

AdditionalDirectiveExamples





ControlDirectives

Controldirectivescontrolhowcodeisassembled.

ListofControlDirectives

Controldirectiveexamplesavailable:

MultipleDirectiveExample1

MultipleDirectiveExample2ORGPIC16CXXXExampleORGPIC18CXXXExampleRADIXExampleSET/EQUExampleUNDEFINE/DEFINEExampleVARIABLE/CONSTANTExample





ConditionalAssemblyDirectives

Conditionalassemblydirectivespermitsectionsofconditionallyassembledcode.

ListofConditionalAssemblyDirectives

Conditionalassemblydirectiveexamplesavailable:

IF/ELSE/ENDIFExample

IFDEFExampleWHILE/ENDWExample





DataDirectives

DataDirectivesarethosethatcontroltheallocationofmemoryandprovideawaytorefertodataitemssymbolically,thatis,bymeaningfulnames.

ListofDataDirectives

Datadirectiveexamplesavailable:

CBLOCK/ENDCExample

CONFIGPIC16CXXXExampleCONFIGPIC18CXXXExampleDAExampleDATAPIC16CXXXExampleDATAPIC18CXXXExampleDBPIC16CXXXExampleDBPIC18CXXXExampleDEPIC16CXXXExampleDEPIC18CXXXExampleFILLPIC16CXXXExampleFILLPIC18CXXXExampleIDLOCPIC16CXXXExampleIDLOCPIC18CXXXExampleRESExample





ListingDirectives

ListingDirectivesarethosedirectivesthatcontroltheMPASMassemblerlistingfileformat.Theyallowthespecificationoftitles,pagination,andotherlistingcontrol.Somelistingdirectivesalsocontrolhowcodeisassembled.

ListofListingDirectives

Listingdirectiveexamplesavailable:

ERRORExample

ERRORLEVELExampleMESSGExample





MacroDirectives

Thesedirectivescontroltheexecutionanddataallocationwithinmacrobodydefinitions.

ListofMacroDirectives

Macrodirectiveexamplesavailable:

EXITMExample

LOCALExampleMACRO/ENDMExample





ObjectFileDirectives

Thesedirectivesareusedonlywhencreatinganobjectfile.

ListofObjectFileDirectives

Objectfiledirectiveexamplesavailable:

BANKISELExample

BANKSELExampleCODEExampleGLOBAL/EXTERNExampleIDATAExamplePAGESELExampleUDATAExampleUDATA_ACSExampleUDATA_OVRExampleUDATA_SHRExample





AdditionalDirectiveExamples

Shortexamplesofuseforeachdirectivearelistedundereachdirectivetopic.SeeDirectives.

Examplesofuseformultipledirectivesareavailablefromthefollowingsources:

readme.asm-SerialEEPROMSupport

ApplicationNotes,TechnicalBriefs

EmbeddedControlHandbook,Volume1(DS00092)

EmbeddedControlHandbook,Volume2MathLibrary(DS00167)EmbeddedControlHandbook,Update2000(DS00711)Website-http://www.microchip.comCodeExamplesandTemplates

MPLABIDEinstallationdirectory

Website-http://www.microchip.com





RelocatableObjects

SincetheintroductionofMPASMassemblerv2.00andMPLINKlinkerv1.00,youhavehadtheabilitytogenerateandlinkprecompiledobjectmodules.Writingsourcecodethatwillbeassembledtoanobjectmoduleisslightlydifferentfromgeneratingexecutablecodedirectlytoahexfile.MPASMassemblerroutinesdesignedforabsoluteaddressassemblywillrequireminormodificationstocompilecorrectlyintorelocatableobjectmodules.

HeaderFiles

ProgramMemoryInstructionOperandsRAMAllocationConfigurationBitsandIDLocationsAccessingLabelsFromOtherModulesPagingandBankingIssuesUnavailableDirectivesGeneratingtheObjectModuleCodeExamples





HeaderFiles

TheMicrochip-suppliedstandardheaderfiles(e.g.,p17c756.inc)shouldbeusedwhengeneratingobjectmodules.Theseheaderfilesdefinethespecialfunctionregistersforthetargetprocessor.



ProgramMemory

ProgrammemorycodemustbeprecededbyaCODEsectiondeclaration.

AbsoluteCode

StartCLRWOPTION:

RelocatableCode

CODEStartCLRWOPTION:

IfmorethanoneCODEsectionisdefinedinasourcefile,eachsectionmusthaveauniquename.Ifthenameisnotspecified,itwillbegiventhedefaultname.code.

Eachprogrammemorysectionmustbecontiguouswithinasinglesourcefile.Asectionmaynotbebrokenintopieceswithinasingesourcefile.

ThephysicaladdressofthecodecanbefixedbysupplyingtheoptionaladdressparameteroftheCODEdirective.Situationswherethismightbenecessaryare:

Specifyinginterruptvectors

Ensuringthatacodesegmentdoesnotoverlappageboundaries



ExampleRelocatableCode

ResetCODEH'0lFF'GOTOStartMainCODECLRWOPTION





InstructionOperands

Therearesomerestrictionsinvolvinginstructionoperands.Instructionoperandsmustbeoftheform:

[HIGH|LOW|UPPER](<relocatablesymbol>+<constantoffset>)

where:

<relocatablesymbol>isanylabelthatdefinesaprogramordatamemoryaddress

<constantoffset>isanexpressionthatisresolvableatassemblytimetoavaluebetween-32768and32767

Either<relocatablesymbol>or<constantoffset>maybeomitted.

Operandsoftheform:

<relocatablesymbol>-<relocatablesymbol>

willbereducedtoaconstantvalueifbothsymbolsaredefinedinthesamecodeordatasection.

IfHIGHisused,onlybits8through15oftheexpressionwillbeused.IfLOWisused,onlybits0through7oftheexpressionwillbeused.IfUPPERisused,onlybits16through21oftheexpressionwillbeused.



RAMAllocation

RAMspacemustbeallocatedinadatasection.Fivetypesofdatasectionsareavailable:

UDATA-Uninitializeddata.Thisisthemostcommontypeofdatasection.Locationsreservedinthissectionarenotinitializedandcanbeaccessedonlybythelabelsdefinedinthissectionorbyindirectaccesses.

UDATA_ACS-Uninitializedaccessdata.ThisdatasectionisusedforvariablesthatwillbeplacedinaccessRAMofPIC18CXXXdevices.AccessRAMisusedasquickdataaccessforspecifiedinstructions.UDATA_OVR-Uninitializedoverlaiddata.Thisdatasectionis

usedforvariablesthatcanbedeclaredatthesameaddressasothervariablesinthesamemoduleorinotherlinkedmodules.Atypicaluseofthissectionisfortemporaryvariables.UDATA_SHR-Uninitializedshareddata.Thisdatasectionis

usedforvariablesthatwillbeplacedinRAMthatisunbankedorsharedacrossallbanks.IDATA-Initializeddata.Thelinkerwillgeneratealookuptable

thatcanbeusedtoinitializethevariablesinthissectiontothespecifiedvalues.Thelocationsreservedbythissectioncanbeaccessedonlybythelabelsdefinedinthissectionorbyindirectaccesses.

Thefollowingexampleshowshowadatadeclarationmightbecreated.

AbsoluteCode

CBLOCK0x20InputGain,OutputGain;Controlloopgains

HistoryVector;Mustbeinitializedto0Templ,Temp2,Temp3;UsedforinternalcalculationsENDC

RelocatableCode

IDATAHistoryVectorDB0UDATAInputGainRES1OutputGainRES1UDATA_OVRTemplRES1Temp2RES1Temp3RES1

Ifnecessary,thelocationofthesectionmaybefixedinmemorybysupplyingtheoptionaladdressparameter.Ifmorethanoneofeachsectiontypeisspecified,eachsectionmusthaveauniquename.Ifanameisnotprovided,thedefaultsectionnamesare:.idata,.udata,.udata_acs,.udata_shr,and.udata_ovr.

WhendefininginitializeddatainanIDATAsection,thedirectivesDB,DW,andDATAcanbeused.DBwilldefinesuccessivebytesofdatamemory.DWandDATAwilldefinesuccessivewordsofdatamemoryinlow-byte/high-byteorder.Thefollowingexampleshowshowdatawillbeinitialized.

RelocatableCode

00001LISTp=17C4400002IDATA000001020300003BytesDB1,2,300033412785600004WordsDWH'1234',H'5678'00074142430000005StringDB"ABC",0







ConfigurationBitsandIDLocations

ConfigurationbitsandIDlocationscanstillbedefinedinarelocatableobjectusingthe__CONFIGand__IDLOCSdirectives.Onlyonelinkedmodulecanspecifythesedirectives.TheyshouldbeusedpriortodeclaringanyCODEsections.Afterusingthesedirectives,thecurrentsectionisundefined.



AccessingLabelsFromOtherModules

LabelsthataredefinedinonemoduleforuseinothermodulesmustbeexportedusingtheGLOBALdirective.LabelsmustbedefinedbeforetheyaredeclaredGLOBAL.ModulesthatusetheselabelsmustusetheEXTERNdirectivetodeclaretheexistenceoftheselabels.AnexampleofusingtheGLOBALandEXTERNdirectivesisshownbelow.

RelocatableCode,DefiningModule

UDATAInputGainRES1OutputGainRES1GLOBALInputGain,OutputGainCODEFilterGLOBALFilter:;Filtercode

RelocatableCode,ReferencingModule

EXTERNInputGain,OutputGain,FilterUDATAReadingRES1CODE...MOVLWGAIN1MOVWFInputGainMOVLWGAIN2MOVWFOutputGainMOVFReading,WCALLFilter





PagingandBankingIssues

Inmanycases,RAMallocationwillspanmultiplebanks,andexecutablecodewillspanmultiplepages.Inthesecases,itisnecessarytoperformproperbankandpageset-uptoproperlyaccessthelabels.However,sincetheabsoluteaddressesofthesevariableandaddresslabelsarenotknownatassemblytime,itisnotalwayspossibletoplacethepropercodeinthesourcefile.Forthesesituations,twonewdirectives,BANKSELandPAGESELhavebeenadded.Thesedirectivesinstructthelinkertogeneratethecorrectbankorpageselectingcodeforaspecifiedlabel.Anexampleofhowcodeshouldbeconvertedisshownbelow.

AbsoluteCode

LISTP=12C509#include"P12C509.INC"VarlEQUH'10'Var2EQUH'30'...MOVLWInitialValueBCFFSR,5MOVWFVarlBSFFSR,5MOVWFVar2BSFSTATUS,PA0CALLSubroutine...SubroutineCLRW;InPage1...RETLW0

RelocatableCode



LISTP=12C509#include"P12C509.INC"UDATAVarlRES1Var2RES1...CODEMOVLWInitialValueBANKSELVarlMOVWFVarlBANKSELVar2MOVWFVar2PAGESELSubroutineCALLSubroutine...SubroutineCLRW...RETLW0





UnavailableDirectives

Macrocapabilityandnearlyalldirectivesareavailablewhengeneratinganobjectfile.TheonlydirectivethatisnotallowedistheORGdirective.ThiscanbereplacedbyspecifyinganabsoluteCODEsegment,asshownbelow.

AbsoluteCode

ResetORGH'01FF'GOTOStart

RelocatableCode

ResetCODEH'0lFF'GOTOStart





GeneratingtheObjectModule

Oncethecodeconversioniscomplete,theobjectmoduleisgeneratedbyrequestinganobjectfileonthecommandlineorintheshellinterface.WhenusingMPASMassemblerforWindows,checkthecheckboxlabeled"ObjectFile."WhenusingtheDOScommandlineinterface,specifythe/ooptionandtoggle"AssembletoObjectFile"to"Yes."Theoutputfilewillhavea.oextension.



CodeExamples

ThefollowingisextractedfromtheexamplemultiplyroutinesgivenasasamplewithMPASMassembler.Mostofthecommentshavebeenstrippedforbrevity.

AbsoluteCodebecomesRelocatableCode,CallingFileandRelocatableCode,LibraryRoutine.

AbsoluteCode

LISTP=16C54#INCLUDE"P16C5X.INC"cblockH'020'mulcnd;8bitmultiplicandmulplr;8bitmultiplierH_byte;Highbyteofthe16bitresultL_byte;Lowbyteofthe16bitresultcount;loopcounterendcmpyclrfH_byteclrfL_bytemovlw8movwfcountmovfmulcnd,wbcfSTATUS,C;ClearcarrybitLooprrfmulplr,FbtfscSTATUS,CaddwfH_byte,FrrfH_byte,FrrfL_byte,Fdecfszcount,Fgotoloopretlw0;*******************************************************

;TestProgram;*******************************************************startclrwoptionmainmovfPORTB,wmovwfmulplr;multiplier(inmulplr)=05movfPORTB,Wmovwfmulcndcall_mcallmpy;TheresultisinF12&F13;H_byte&L_bytegotomainORG01FFhgotostartEND

Sinceaneight-by-eightbitmultiplyisauseful,genericroutine,itwouldbehandytobreakthisoffintoaseparateobjectfilethatcanbelinkedinwhenrequired.Theabovefilecanbebrokenintotwofiles:acallingfilerepresentinganapplicationandagenericroutinethatcouldbeincorporatedinalibrary.

RelocatableCode,CallingFile

LISTP=16C54#INCLUDE"P16C5x.INC"EXTERNmulcnd,mulplr,H_byte,L_byteEXTERNmpyCODEstartclrwoptionmainmovfPORTB,WmovwfmulplrmovfPORTB,Wmovwfmulcndcall_mcallmpy;TheresultisinH_byte&L_bytegotomain

MicrochipTechnologyInc.Microchip'sWebSite

ResetCODEH'0lFF'gotostartEND

RelocatableCode,LibraryRoutine

LISTP=16C54#INCLUDE"P16C5x.INC"UDATAmulcndRESl;8bitmultiplicandmulplrRES1;8bitmultiplierH_byteRES1;Highbyteofthe16bitresultL_byteRES1;Lowbyteofthe16bitresultcountRES1;loopcounterGLOBALmulcnd,mulplr,H_byte,L_byteCODEmpyGLOBALmpyclrfH_byteclrfL_bytemovlw8movwfcountmovfmuland,WbcfSTATUS,C;Clearcarrybitlooprrfmulplr,FbtfscSTATUS,CaddwfH_byte,FrrfH_byte,FrrfL_byte,Fdecfszcount,Fgotoloopretlw0END


Voice:(480)792-7200Fax:(480)899-9210





MacroLanguage

Macrosareuserdefinedsetsofinstructionsanddirectivesthatwillbeevaluatedin-linewiththeassemblersourcecodewheneverthemacroisinvoked.

Macrosconsistofsequencesofassemblerinstructionsanddirectives.Theycanbewrittentoacceptarguments,makingthemquiteflexible.Theiradvantagesare:

Higherlevelsofabstraction,improvingreadabilityandreliability.

Consistentsolutionstofrequentlyperformedfunctions.Simplifiedchanges.Improvedtestability.

Applicationsmightincludecreatingcomplextables,frequentlyusedcode,andcomplexoperations.

MacroSyntax

MacroDirectivesDefinedMacroTextSubstitutionMacroUsageMacroCodeExamples





MacroSyntax

MPASMassemblermacrosaredefinedaccordingtothefollowingsyntax:

<label>macro[<arg1>,<arg2>...,<argn>]::endm

where<label>isavalidassemblerlabeland<arg>isanynumberofoptionalargumentssuppliedtothemacro(thatwillfitonthesourceline.)Thevaluesassignedtotheseargumentsatthetimethemacroisinvokedwillbesubstitutedwherevertheargumentnameoccursinthebodyofthemacro.

ThebodyofamacromaybecomprisedofMPASMassemblerdirectives,PICmicroMCUassemblyinstructions,orMPASMassemblermacrodirectives(LOCALforexample.)TheassemblercontinuestoprocessthebodyofthemacrountilanEXITMorENDMdirectiveisencountered.

Note:Forwardreferencestomacrosarenotpermitted.





MacroDirectivesDefined

Therearedirectivesthatareuniquetomacrodefinitions.Theycannotbeusedoutofthemacrocontext.

MacroDirectives

Whenwritingmacros,youcanuseanyofthesedirectivesPLUSanyotherdirectivessupportedbytheassembler.

Note:Theprevioussyntaxofthe"dot"formatformacrospecificdirectivesisnolongersupported.Forcompatibilityreasons,oldASM17codethatusesthisformatwillassemblebyMPASMassembler,butasmentionedbefore,youareencouragedtowritenewcodebasedontheconstructsdefinedwithinthishelpfiletoensureupwardcompatibility.





MacroTextSubstitution

Stringreplacementandexpressionevaluationmayappearwithinthebodyofamacro.

Command Description<arg> Substitutetheargumenttextsuppliedaspartofthemacroinvocation.

#v(<expr>)Returntheintegervalueof<expr>.Typically,usedtocreateuniquevariablenameswithcommonprefixesorsuffixes.Cannotbeusedinconditionalassemblydirectives(e.g.IFDEF,WHILE).

Argumentsmaybeusedanywherewithinthebodyofthemacro,exceptaspartofnormalexpression.Forexample,thefollowingmacro:

define_tablemacrolocala=0whilea<3entry#v(a)dw0a+=1endwendmwheninvoked,wouldgenerate:entry0dw0entry1dw0entry2dw0entry3dw0





MacroUsage

Oncethemacrohasbeendefined,itcanbeinvokedatanypointwithinthesourcemodulebyusingamacrocall,asdescribedbelow:

<macro_name>[<arg>,...,<arg>]

where<macro_name>isthenameofapreviouslydefinedmacroandargumentsaresuppliedasrequired.

Themacrocallitselfwillnotoccupyanylocationsinmemory.However,themacroexpansionwillbeginatthecurrentmemorylocation.Commasmaybeusedtoreserveanargumentposition.Inthiscase,theargumentwillbeanemptystring.Theargumentlististerminatedbywhitespaceorasemicolon.

TheEXITMdirectiveprovidesanalternatemethodforterminatingamacroexpansion.Duringamacroexpansion,thisdirectivecausesexpansionofthecurrentmacrotostopandallcodebetweentheEXITMandtheENDMdirectivesforthismacrotobeignored.Ifmacrosarenested,EXITMcausescodegenerationtoreturntothepreviouslevelofmacroexpansion.



MacroCodeExamples

Thefollowingareexamplesofmacros:

Eight-by-EightMultiply

ConstantCompare

Eight-by-EightMultiply

subtitle"macrodefinitions"page;;multiply-isaneightbyeightmultiplymacro,;executinginprogrammemory,optimizedforspeed,;straightlinecode.;;Thismacrohasfiveparametersasdefinedhere:;arg1-firsteightbitliteraltobemultiplied;arg2-secondeightbitliteraltobemultiplied;dest_hi-memorylocationforhighbyteofresult;dest_lo-memorylocationforlowbyteofresult;temp-memorylocationfortemporarystorage;;Duringtheexecutionofthismacro,thewregisteris;destroyed.;;Theresultofmultiplyisa16bitvaluestoredinthe;twoeightbitregisters(dest_hi,dest_lo);;ThismacroiswrittenforthePIC17C42.;;multiplymacroarg1,arg2,dest_hi,dest_lo,temp;

locali=0;Establishalocalindex;variableandinitializeit.;movlwarg1;Setuptheeightbitmovwftemp;literalmultiplierinthe;memorylocationtemp.;movlwarg2;Setuptheeightbit;literalmultiplicandinthe;wregister.;clrfdest_hi,F;Clearboththehighandclrfdest_lo,F;thelowdestination;registers.;bcfALUSTA,C;Clearthecarrybit.;whilei<8;Usethelooptocheckall;eightbitsofthe;multiplier(temp).;btfsctemp,i;Testthecurrentaddwfdest_hi,F;multiplierbit,iftemp,I;thenaddthemultiplicand;tothehighregister.;rrcfdest_hi,F;Foreachpassintherrcfdest_lo,F;loop,rightshifteach;destinationregisterusing;thecarrybit.;i+=1;Placethisincrementin;column1toavoid;Warning[207].endw;endm;

Themacrodeclaresalloftherequiredarguments.Inthiscase,therearefive.TheLOCALdirectivethenestablishesalocalvariable"i"thatwillbeusedasanindexcounter.Itisinitializedtozero.Anumberofassemblerinstructionsarethenincluded.Whenthemacroisexecuted,theseinstructionswillbewritteninlinewiththerestoftheassemblersourcecode.Themacrowritesthemultiplicationcodeusinganalgorithmthataddsforeachbitsetintheeightbitsofthemultiplierandusesrightshifts.TheWHILEdirectiveisusedforthisfunction,continuingtheloopuntil"I"isgreaterthanorequaltoeight.

ConstantCompare

Asanotherexample,ifthefollowingmacrowerewritten:

include"16cxx.reg";;comparefiletoconstantandjumpiffile;>=constant.;cfl_jgemacrofile,con,jump_tomovlwcon&0xffsubwffile,wbtfscstatus,carrygotojump_toendm

andinvokedby:

cfl_jgeswitch_val,max_switch,switch_on

itwouldproduce:

movlwmax_switch&0xffsubwfswitch_val,wbtfscstatus,carrygotoswitch_on







ExpressionSyntaxandOperation

Variousexpressionformats,syntax,andoperationsusedbyMPASMassembleraredescribedhere.

TextStrings

NumericConstantsandRadixArithmeticOperatorsandPrecedence



TextStrings

A"string"isasequenceofanyvalidASCIIcharacter(ofthedecimalrangeof0to127)enclosedbydoublequotes.

Stringsmaybeofanylengththatwillfitwithina255columnsourceline.Ifamatchingquotemarkisfound,thestringends.Ifnoneisfoundbeforetheendoftheline,thestringwillendattheendoftheline.Whilethereisnodirectprovisionforcontinuationontoasecondline,itisgenerallynoproblemtouseasecondDWdirectiveforthenextline.

TheDWdirectivewillstoretheentirestringintosuccessivewords.Ifastringhasanoddnumberofcharacters(bytes),theDWandDATAdirectiveswillpadtheendofthestringwithonebyteofzero(00).

Ifastringisusedasaliteraloperand,itmustbeexactlyonecharacterlong,oranerrorwilloccur.

CodeExamples

Seetheexamplesbelowfortheobjectcodegeneratedbydifferentstatementsinvolvingstrings.

74657374696Edw"testingoutputstringone\n"67206F757470757420737472696E67206F6E650A#definestr"testingoutputstringtwo"B061movlw"a"74657374696Edata"testingfirstoutputstring"67206669727374206F757470



757420737472696E6700

EscapeCharacters

TheassembleracceptstheANSI`C'escapesequencestorepresentcertainspecialcontrolcharacters:

TABLE:ANSI`C'ESCAPESEQUENCESEscapeCharacter Description Hex

Value\a Bell(alert)character 07\b Backspacecharacter 08\f Formfeedcharacter 0C\n Newlinecharacter 0A\r Carriagereturncharacter 0D\t Horizontaltabcharacter 09\v Verticaltabcharacter 0B\\ Backslash 5C\? Questionmarkcharacter 3F\' Singlequote(apostrophe) 27\" Doublequotecharacter 22

\0OO Octalnumber(zero,Octaldigit,Octaldigit) \xHH Hexadecimalnumber





NumericConstantsandRadix

MPASMassemblersupportsthefollowingradixformsforconstants:hexadecimal,decimal,octal,binary,andASCII.Thedefaultradixishexadecimal;thedefaultradixdetermineswhatvaluewillbeassignedtoconstantsintheobjectfilewhenaradixisnotexplicitlyspecifiedbyabasedescriptor.

Note:Theradixfornumericconstantscanbedifferentfromthedefaultradixspecifedwiththedirectivesradixorlistr=.Also,allowabledefaultradicesarelimitedtohexadecimal,decimal,andoctal.

Constantscanbeoptionallyprecededbyaplusorminussign.Ifunsigned,thevalueisassumedtobepositive.

Note:Intermediatevaluesinconstantexpressionsaretreatedas32-bitunsignedintegers.Wheneveranattemptismadetoplaceaconstantinafieldforwhichitistoolarge,atruncationwarningwillbeissued.

Thefollowingtablepresentsthevariousradixspecifications:

TABLE:RADIXSPECIFICATIONSType Syntax Example

Decimal D'<digits>'.'<digits>'

D'100'.'100'

Hexadecimal H'<hex_digits>'0x<hex_digits>H'9f'0x9f

Octal O'<octal_digits>' O'777'Binary B'<binary_digits>' B'00111001'

ASCII A'<character>''<character>'

A'C''C'



ArithmeticOperatorsandPrecedence

ArithmaticoperatorsandtheirprecedencearelistedinTable:ArithmeticOperatorsandPrecedence.

Selectedoperatorsarediscussedingreaterdetailinsubsectionsfollowingthetable.

TABLE:ARITHMETICOPERATORSANDPRECEDENCEOperator Example

$ Current/Returnprogramcounter goto$+3( LeftParenthesis 1+(d*4)) RightParenthesis (Length+1)*256! ItemNOT(logicalcomplement) if!(a==b)- Negation(2'scomplement) -1*Length~ Complement flags=~flagshigh Returnhighbyte movlwhighCTR_Tablelow Returnlowbyte movlwlowCTR_Tableupper Returnupperbyte movlwupperCTR_Table* Multiply a=b*c/ Divide a=b/c% Modulus entry_len=tot_len%16+ Add tot_len=entry_len*8+1- Subtract entry_len=(tot-1)/8<< Leftshift flags=flags<<1>> Rightshift flags=flags>>1>= Greaterorequal ifentry_idx>=num_entries> Greaterthan ifentry_idx>num_entries< Lessthan ifentry_idx<num_entries<= Lessorequal ifentry_idx<=num_entries== Equalto ifentry_idx==num_entries= Notequalto ifentry_idx!=num_entries& BitwiseAND flags=flags&ERROR_BIT^ BitwiseexclusiveOR flags=flags^ERROR_BIT| BitwiseinclusiveOR flags=flags|ERROR_BIT&& LogicalAND if(len==512)&&(b==c)|| LogicalOR if(len==512)||(b==c)= Setequalto entry_index=0+= Addto,setequal entry_index+=1

-= Subtract,setequal entry_index-=1*= Multiply,setequal entry_index*=entry_length/= Divide,setequal entry_total/=entry_length%= Modulus,setequal entry_index%=8<<= Leftshift,setequal flags<<=3>>= Rightshift,setequal flags>>=3&= AND,setequal flags&=ERROR_FLAG|= InclusiveOR,setequal flags|=ERROR_FLAG^= ExclusiveOR,setequal flags^=ERROR_FLAG++ Increment i++-- Decrement i--

High/Low/Upper

Syntax

high<operand>low<operand>upper<operand>

Description

Theseoperatorsareusedtoreturnonebyteofamulti-bytelabelvalue.Thisisdonetohandledynamicpointercalculationsasmightbeusedwithtablereadandwriteinstructions.

Example

movlwlowsize;handlethelsb'smovpfwreg,lowsize_lomovlwhighsize;handlethemsb'smovpfwreg,highsize_hi

Increment/Decrement(++/--)



Syntax

<variable>++<variable>--

Description

Incrementsordecrementsavariablevalue.Theseoperatorscanonlybeusedonalinebythemselves;theycannotbeembeddedwithinotherexpressionevaluation.

Example

LoopCount=4whileLoopCount>0rlfReg,fLoopCount--endw





Troubleshooting

Errormessages,warningmessagesandgeneralmessagesareproducedbytheMPASMassembler.Thesemessagesalwaysappearinthelistingfiledirectlyaboveeachlineinwhichtheerroroccurred.

Themessagesarestoredintheerrorfile(.err)ifnoMPASMassembleroptionsarespecified.Ifthe/e-optionisused(turnserrorfileoff),thenthemessageswillappearonthescreen.Ifthe/q(quietmode)optionisusedwiththe/e-,thenthemessageswillnotdisplayonthescreenorinanerrorfile.Themessageswillstillappearinthelistingfile.

Limitationsoftheassemblertoolarealsolistedhere.

AssemblerErrors

AssemblerWarningsAssemblerMessagesAssemblerLimitations



AssemblerErrors

MPASMassemblererrorsarelistednumericallybelow:

101ERROR:

Usererror,invokedwiththeERRORdirective.

102Outofmemory.

Notenoughmemoryformacros,#definesorinternalprocessing.EliminateanyTSR's,closeanyopenapplications,andtryassemblingthefileagain.IfthiserrorwasobtainedusingtheRealModeDOSexecutable,tryusingeithertheWindowsversion(MPASMWIN)orDPMIversion(MPASM_DP)

103Symboltablefull.

Nomorememoryavailableforthesymboltable.EliminateanyTSR's,closeanyopenapplications,andtryassemblingthefileagain.IfthiserrorwasobtainedusingtheRealModeDOSexecutable,tryusingeithertheWindowsversion(MPASMWIN)orDPMIversion(MPASM_DP)

104Tempfilecreationerror.

Couldnotcreateatemporaryfile.Checktheavailablediskspace.

105Cannotopenfile.

Couldnotopenafile.Ifitisasourcefile,thefilemaynotexist.Ifitisanoutputfile,theoldversionmaybewriteprotected.

106Stringsubstitutiontoocomplex.

Toomuchnestingof#defines.

107Illegaldigit.

Anillegaldigitinanumber.Validdigitsare0-1forbinary,0-7foroctal,0-9fordecimal,and0-9,a-f,andA-Fforhexadecimal.

108Illegalcharacter.

Anillegalcharacterinalabel.Validcharactersforlabelsarealphabetic(a..f,A..F),numeric(0-9),theunderscore(_),andthequestionmark(?).Labelsmaynotbeginwithanumeric.

109Unmatched(

Anopenparenthesisdidnothaveamatchingcloseparenthesis.Forexample,"DATA(1+2".

110Unmatched)

Ancloseparenthesisdidnothaveamatchingopenparenthesis.Forexample,DATA1+2).

111Missingsymbol.

AnEQUorSETstatementdidnothaveasymboltoassignthevalueto.

112Missingoperator.

Anarithmeticoperatorwasmissingfromanexpression.Forexample,DATA12.

113Symbolnotpreviouslydefined.

Asymbolwasreferencedthathasnotyetbeendefined.Onlyaddressesmaybeusedasforwardreferences.Constantsandvariablesmustbedeclaredbeforetheyareused.

114Dividebyzero.

Divisionbyzeroencounteredduringanexpressionevaluation.

115Duplicatelabel.

Alabelwasdeclaredasaconstant(e.g.,withtheEQUorCBLOCKdirective)inmorethanonelocation.

116Addresslabelduplicatedordifferentinsecondpass.

Thesamelabelwasusedintwolocations.Alternately,thelabelwasusedonlyoncebutevaluatedtoadifferentlocationonthesecondpass.Thisoftenhappenswhenuserstrytowritepage-bitsettingmacrosthatgeneratedifferentnumbersofinstructionsbasedonthedestination.

117Addresswrappedaround0.

ThelocationcountercanonlyadvancetoFFFF.Afterthat,itwrapsbackto0.

118Overwritingpreviousaddresscontents.

Codewaspreviouslygeneratedforthisaddress.

119Codetoofragmented.

Thecodeisbrokenintotoomanypieces.Thiserrorisveryrare,andwillonlyoccurinsourcecodethatreferencesaddressesabove32K(includingconfigurationbits).

120Callorjumpnotallowedatthisaddress.

Acallorjumpcannotbemadetothisaddress.Forexample,CALLdestinationsonthePIC16C5xfamilymustbeinthelowerhalfofthepage.

121Illegallabel.

Labelsarenotallowedoncertaindirectivelines.Simplyputthelabelonitsownline,abovethedirective.Also,HIGH,LOW,PAGE,andBANKarenotallowedaslabels.

122Illegalopcode.

Tokenisnotavalidopcode.

123Illegaldirective.

Directiveisnotallowedfortheselectedprocessor;forexample,the

__IDLOCSdirectiveonthePIC17C42.

124Illegalargument.

Anillegaldirectiveargument;forexample,LISTSTUPID.

125Illegalcondition.

Abadconditionalassembly.Forexample,anunmatchedENDIF.

126Argumentoutofrange.

Opcodeordirectiveargumentoutofthevalidrange;forexample,TRIS10.

127Toomanyarguments.

Toomanyargumentsspecifiedforamacrocall.

128Missingargument(s).

Notenoughargumentsforamacrocalloranopcode.

129Expected.

Expectedacertaintypeofargument.Theexpectedlistwillbeprovided.

130Processortypepreviouslydefined.

Adifferentfamilyofprocessorisbeingselected.

131Processortypeisundefined.

Codeisbeinggeneratedbeforetheprocessorhasbeendefined.Notethatuntiltheprocessorisdefined,theopcodesetisnotknown.

132Unknownprocessor.

Theselectedprocessorisnotavalidprocessor.

133HexfileformatINHX32required.

Anaddressabove32Kwasspecified.Forexample,specifyingtheconfigurationbitsonthePIC17CXXXfamily.

134Illegalhexfileformat.

AnillegalhexfileformatwasspecifiedintheLISTdirective.

135Macronamemissing.

Amacrowasdefinedwithoutaname.

136Duplicatemacroname.

Amacronamewasduplicated.

137Macrosnestedtoodeep.

Themaximummacronestinglevelwasexceeded.

138Includefilesnestedtoodeep.

Themaximumincludefilenestinglevelwasexceeded.

139Maximumof100linesinsideWHILE-ENDW.

AWHILE-ENDWcancontainatmost100lines.

140WHILEmustterminatewithin256iterations.

AWHILE-ENDWloopmustterminatewithin256iterations.Thisistopreventinfiniteassembly.

141WHILEsnestedtoodeep.

ThemaximumWHILE-ENDWnestinglevelwasexceeded.

142IFsnestedtoodeep.

ThemaximumIFnestinglevelwasexceeded.

143Illegalnesting.

Macros,IF'sandWHILE'smustbecompletelynested;theycannotoverlap.IfyouhaveanIFwithinaWHILEloop,theENDIFmustcomebeforetheENDW.

144UnmatchedENDC.

ENDCfoundwithoutaCBLOCK.

145UnmatchedENDM.

ENDMfoundwithoutaMACROdefinition.

146UnmatchedEXITM.

EXITMfoundwithoutaMACROdefinition.

147Directivenotallowedwhengeneratinganobjectfile.

TheORGdirectiveisnotallowedwhengeneratinganobjectfile.Instead,declareadataorcodesection,specifyingtheaddressifnecessary.

148Expandedsourcelineexceeded200characters.

Themaximumlengthofasourceline,after#DEFINEandmacroparametersubstitution,is200characters.Notethat#DEFINEsubstitutiondoesnotincludecomments,butmacroparametersubstitutiondoes.

149Directiveonlyallowedwhengeneratinganobjectfilesection.

Certaindirectives,suchasGLOBALandEXTERN,onlyhavemeaningwhenanobjectfileisgenerated.Theycannotbeusedwhengeneratingabsolutecode.

150Labelsmustbedefinedinacodeordatasectionwhenmakinganobjectfile.

Whengeneratinganobjectfile,alldataandcodeaddresslabels

mustbedefinedinsideadataorcodesection.SymbolsdefinedbytheEQUandSETdirectivescanbedefinedoutsideofasection.

151Operandcontainsunresolvablelabelsoristoocomplex.

Whengeneratinganobjectfile,operandsmustbeoftheform[HIGH|LOW]([<relocatableaddresslabel>]+[<offset>]).

152Executablecodeanddatamustbedefinedinanappropriatesection.

Whengeneratinganobjectfile,allexecutablecodeanddatadeclarationsmustbeplacedwithinappropriatesections.

153PageorBankbitscannotbeevaluatedfortheoperand.

TheoperandofaPAGESEL,BANKSELorBANKISELdirectivemustbeoftheform<relocatableaddresslabel>or<constant>.

154Eachobjectfilesectionmustbecontiguous.

Objectfilesections,exceptUDATA_OVRsections,cannotbestoppedandrestartedwithinasinglesourcefile.Toresolvethisproblem,eithernameeachsectionwithitsownnameormovethecodeanddatadeclarationssuchthateachsectioniscontiguous.Thiserrorwillalsobegeneratediftwosectionsofdifferenttypesaregiventhesamename.

155Alloverlaidsectionsofthesamename



musthavethesamestartingaddress.

IfmultipleUDATA_OVRsectionswiththesamenamearedeclared,theymustallhavethesamestartingaddress.

156Operandmustbeanaddresslabel.

Whengeneratingobjectfiles,onlyaddresslabelsincodeordatasectionsmaybedeclaredglobal.VariablesdeclaredbytheSETorEQUdirectivesmaynotbeexported.

157UNKNOWNERROR.

Anerrorhasoccurredwhichtheassemblercannotunderstand.Itisnotanyoftheerrorsdescribedinthisappendix.ContactyourMicrochipFieldApplicationEngineer(FAE)ifyoucannotdebugthiserror.



AssemblerWarnings

MPASMassemblerwarningsarelistednumericallybelow:

201Symbolnotpreviouslydefined.

Symbolbeing#undefinedwasnotpreviouslydefined.

202Argumentoutofrange.Leastsignificantbitsused.

Argumentdidnotfitintheallocatedspace.Forexample,literalsmustbe8bits.

203Foundopcodeincolumn1.

Anopcodewasfoundincolumnone,whichisreservedforlabels.

204Foundpseudo-opincolumn1.

Apseudo-opwasfoundincolumnone,whichisreservedforlabels.

205Founddirectiveincolumn1.

Adirectivewasfoundincolumnone,whichisreservedforlabels.

206Foundcalltomacroincolumn1.

Amacrocallwasfoundincolumnone,whichisreservedforlabels.

207Foundlabelaftercolumn1.

Alabelwasfoundaftercolumnone,whichisoftenduetoamisspelledopcode.

208Labeltruncatedat32characters.

Maximumlabellengthis32characters.

209Missingquote.

Atextstringorcharacterwasmissingaquote.Forexample,DATA'a.

210Extra),

Anextracommawasfoundattheendoftheline.

211Extraneousargumentsontheline.

Extraargumentswerefoundontheline.Thesewarningsshouldbeinvestigated,sincetheyareoftenindicationsofthefree-formatparserinterpretingsomethinginamannerotherthanwasintended(tryassemblingOPTIONEQU0x81withLISTFREE).

212Expected

Expectedacertaintypeofargument.Adescriptionshouldbeprovided.Forthewarning,anassumptionismadeabouttheargument.

213TheEXTERNdirectiveshouldonlybe

usedwhenmakinga.ofile.

TheEXTERNdirectiveonlyhasmeaningifanobjectfileisbeingcreated.ThiswarninghasbeensupersededbyError149.

214Unmatched(

Anunmatchedparenthesiswasfound.Thewarningisusediftheparenthesisisnotusedforindicatingorderofevaluation.

215Processorsupersededbycommandline.Verifyprocessorsymbol.

Theprocessorwasspecifiedonthecommandlineaswellasinthesourcefile.Thecommandlinehasprecedence.

216Radixsupersededbycommandline.

Theradixwasspecifiedonthecommandlineaswellasinthesourcefile.Thecommandlinehasprecedence.

217Hexfileformatspecifiedoncommandline.

Thehexfileformatwasspecifiedonthecommandlineaswellasinthesourcefile.Thecommandlinehasprecedence.

218ExpectedDEC,OCT,HEX.WilluseHEX.

Badradixspecification.

219InvalidRAMlocationspecified.

Ifthe__MAXRAMand__BADRAMdirectivesareused,thiswarningflagsuseofanyRAMlocationsdeclaredasinvalidbythesedirectives.Notethattheprovidedheaderfilesinclude__MAXRAMand__BADRAMforeachprocessor.

220Addressexceedsmaximumrangeforthisprocessor.

AROMlocationwasspecifiedthatexceedstheprocessor'smemorysize.

221Invalidmessagenumber.

Themessagenumberspecifiedfordisplayingorhidingisnotavalidmessagenumber.

222Errormessagescannotbedisabled.

ErrormessagescannotbedisabledwiththeERRORLEVELcommand.

223Redefiningprocessor

TheselectedprocessorisbeingreselectedbytheLISTorPROCESSORdirective.

224Useofthisinstructionisnotrecommended.

UseoftheTRISandOPTIONinstructionsisnotrecommendedfor



aPIC16CXXXdevice.

225Invalidlabelinoperand.

Operandwasnotavalidaddress.Forexample,iftheusertriedtoissueaCALLtoaMACROname.

226UNKNOWNWARNING

Awarninghasoccurredwhichtheassemblercannotunderstand.Itisnotanyofthewarningsdescribedinthisappendix.ContactyourMicrochipFieldApplicationEngineer(FAE)ifyoucannotdebugthiswarning.



AssemblerMessages

MPASMassemblermessagesarelistednumericallybelow:

301MESSAGE:

Usermessage,invokedwiththeMESSGdirective.

302Registerinoperandnotinbank0.Ensurethatbankbitsarecorrect.

Registeraddresswasspecifiedbyavaluethatincludedthebankbits.Forexample,RAMlocationsinthePIC16CXXXarespecifiedwith7bitsintheinstructionandoneortwobankbits.

303Programwordtoolarge.Truncatedtocoresize.

ProgramwordsforthePIC16C5Xmayonlybe12-bits;programwordsforthePIC16CXXXmayonlybe14-bits.

304IDLocationsvaluetoolarge.Lastfourhexdigitsused.

OnlyfourhexdigitsareallowedfortheIDlocations.

305Usingdefaultdestinationof1(file).

Ifnodestinationbitisspecified,thedefaultisused.

306Crossingpageboundary-ensurepagebitsareset.

Generatedcodeiscrossingapageboundary.

307Settingpagebits.

PagebitsarebeingsetwiththeLCALLorLGOTOpseudo-op.

308Warninglevelsupersededbycommandlinevalue.

Thewarninglevelwasspecifiedonthecommandlineaswellasinthesourcefile.Thecommandlinehasprecedence.

309Macroexpansionsupersededbycommandline.

Macroexpansionwasspecifiedonthecommandlineaswellasinthesourcefile.Thecommandlinehasprecedence.

310SupersedingcurrentmaximumRAMandRAMmap.

The__MAXRAMdirectivehasbeenusedpreviously.

312PageorBankselectionnotneededforthisdevice.Nocodegenerated.

IfadevicecontainsonlyoneROMpageorRAMbank,nopageorbankselectionisrequired,andanyPAGESEL,BANKSEL,or



BANKISELdirectiveswillnotgenerateanycode.

313CBLOCKconstantswillstartwithavalueof0.

IfthefirstCBLOCKinthesourcefilehasnostartingvaluespecified,thismessagewillbegenerated.

314UNKNOWNMESSAGE

Amessagehasoccurredwhichtheassemblercannotunderstand.Itisnotanyofthemessagesdescribedinthisappendix.ContactyourMicrochipFieldApplicationEngineer(FAE)ifyoucannotdebugthismessage.





AssemblerLimitations

GeneralLimitations

MPASMassembleronlylooksinthepathoftheexecutableorthefilebeingassembledforincludedfiles.Therefore,IncludePathinformationenteredintheMPLABIDEEditProjectdialogwillNOTbeusedbytheassembler.

Sourcelinelimit(expanded)=200charactersFilenamelimit=8.3format

DirectiveLimitations

whilenestlimit=8deepwhilelooplimit=100lineswhileiterationlimit=256

ifnestlimit=16deepincludenestlimit=5levelsincludemax.numberoffiles=255macronestlimit=16deepmacrosourcelinelimit(expanded)=

200charactersDonotuse#includesinmacros.





InstructionSets

PICmicroMCUinstructionsetsareusedindevelopingapplicationswithMPASMassembler,MPLINKobjectlinkerandMPLIBobjectlibrarian.

Instructionsarelistedherebasedondevicecoresize.Asofthetimeofpublicationofthisdocument,thefollowingcoresizesmaptothefollowingdevices:

12-BitCoreDevices:PIC12C5XX,PIC12CE5XX,PIC16X5X,PIC16C505

14-BitCoreDevices:PIC12C67X,PIC12CE67X,PIC12F629/675,PIC16XXXX16-BitCoreDevices:PIC17CXXXExtended16-BitCoreDevices:PIC18XXXXX

Topicscoveredare:

KeytoPICmicroFamilyInstructionSets

12-BitCoreInstructionSet14-BitCoreInstructionSet16-BitCoreInstructionSetKeytoExtended16-BitCoreInstructionSetExtended16-BitCoreInstructionSet



KeytoPICmicroFamilyInstructionSets

Field DescriptionRegisterFiles

dest DestinationeithertheWREGregisterorthespecifiedregisterfilelocation.Seed.f Registerfileaddress(5-bit,7-bitor8-bit).p Peripheralregisterfileaddress(5-bit).r PortforTRIS.

xDon'tcare(`0'or`1').Theassemblerwillgeneratecodewithx=0.ItistherecommendedformofuseforcompatibilitywithallMicrochipsoftwaretools.

Literals

k

Literalfield,constantdataorlabel.k4-bit.kk8-bit.kkk12-bit.

Bits

b Bitaddresswithinan8-bitfileregister(0to7).

dDestinationselectbit.d=0:storeresultinWREGd=1:storeresultinfileregisterf(default)

iTablepointercontrol.i=0:donotchange.i=1:incrementafterinstrucitonexecution.

sDestinationselectbit.s=0:storeresultinfileregisterfandWREGs=1:storeresultinfileregisterf(default)

tTablebyteselect.t=0:performoperationonlowerbyte.t=1:performoperationonupperbyte.

'' Bitvalues,asopposedtoHexvalue.NamedRegistersBSR BankSelectRegister.UsedtoselectthecurrentRAMbank.OPTION OPTIONRegister.PCL ProgramCounterLowByte.PCH ProgramCounterHighByte.PCLATH ProgramCounterHighByteLatch.PCLATU ProgramCounterUpperByteLatch.PRODH ProductofMultiplyHighByte.PRODL ProductofMultiplyLowByte.TBLATH TableLatch(TBLAT)HighByte.TBLATL TableLatch(TBLAT)LowByte.

TBLPTR 16-bitTablePointer(TBLPTRH:TBLPTRL).PointstoaProgramMemorylocation.WREG Workingregister(accumulator).NamedBitsC,DC,Z,OV,N ALUStatusbits:Carry,DigitCarry,Zero,Overflow,Negative.

TO Time-outbit.PD Power-downbit.GIE GlobalInterruptEnablebit(s).NamedDeviceFeaturesPC ProgramCounter.TOS Top-of-Stack.WDT WatchdogTimer.Misc.Descriptors() Contents.→,↔ Assignedto.<> Registerbitfield.





12-BitCoreInstructionSet

Microchip'sbase-line8-bitmicrocontrollerfamilyusesa12-bitwideinstructionset.Allinstructionsexecuteinasingleinstructioncycleunlessotherwisenoted.AnyunusedopcodeisexecutedasaNOP.

Theinstructionsetisgroupedintothefollowingcatagories:Byte-orientedfileregisteroperations,bit-orientedfileregisteroperations,andcoreliteralandcontroloperations.Instructionsarelistedbycatagoryinthetablesbelow.InstructionopcodeisshowinHexbycertainmakingassumptions,eitherlistedinthekeyorasafootnote.Formoreinformationontheopcodebitvaluesforeachinstruction,aswellasthenumberofcyclesperinstruction,statusbitsaffectedandcompleteinstructiondetails,seethereleventdevicedatasheet.

TABLE:12-BITCOREBYTE-ORIENTEDFILEREGISTEROPERATIONS

Hex Mnemonic Description Function1Ef* ADDWF f,d AddWandf WREG+f→dest

16f* ANDWF f,d ANDWandf WREG.AND.f→dest

06f CLRF f Clearf 0→f

040 CLRW ClearW 0→WREG

26f* COMF f,d Complementf .NOT.f→dest

0Ef* DECF f,d Decrementf f-1→dest

2Ef* DECFSZ f,d Decrementf,skipifzero f-1→dest,skipifzero

2Af* INCF f,d Incrementf f+1→dest

3Ef* INCFSZ f,d Incrementf,skipifzero f+1→dest,skipifzero

12f* IORWF f,d InclusiveORWandf WREG.OR.f→dest

22f* MOVF f,d Movef f→dest

02f MOVWF f MoveWtof WREG→f

000 NOP Nooperation

36f* RLF f,d Rotateleftf



32f* RRF f,d Rotaterightf

0Af* SUBWF f,d SubtractWfromf f-WREG→dest

3Af* SWAPF f,d Swaphalvesf f(0:3)↔f(4:7)→dest

1Af* XORWF f,d ExclusiveORWandf WREG.XOR.f→dest*Assumingdefaultbitvalueford.

TABLE:12-BITCOREBIT-ORIENTEDFILEREGISTEROPERATIONS

Hex Mnemonic Description Function4bf BCF f,b Bitclearf 0→f(b)

5bf BSF f,b Bitsetf 1→f(b)

6bf BTFSC f,b Bittest,skipifclear skipiff(b)=0

7bf BTFSS f,b Bittest,skipifset skipiff(b)=1

TABLE:12-BITCORELITERALANDCONTROLOPERATIONSHex Mnemonic Description FunctionEkk ANDLW kk ANDliteralandW kk.AND.WREG→WREG

9kk CALL kk Callsubroutine PC+1→TOS,kk→PC

004 CLRWDT Clearwatchdogtimer 0→WDT(andPrescalerifassigned)

Akk GOTO kk Gotoaddress(kisninebits) kk→PC(9bits)

Dkk IORLW kk Incl.ORliteralandW kk.OR.WREG→WREG

Ckk MOVLW kk MoveLiteraltoW kk→WREG

002 OPTION LoadOPTIONRegister WREG→OPTIONRegister

8kk RETLW kk ReturnwithliteralinW kk→WREG,TOS→PC

003 SLEEP GointoStandbyMode 0→WDT,stoposcillator

00r TRIS r Tristateportr WREG→I/Ocontrolregr

Fkk XORLW kk ExclusiveORliteralandW kk.XOR.WREG→WREG




Microchip'smid-range8-bitmicrocontrollerfamilyusesa14-bitwideinstructionset.Thisinstructionsetconsistsof36instructions,eachasingle14-bitwideword.Mostinstructionsoperateonafileregister,f,andtheworkingregister,WREG(accumulator).TheresultcanbedirectedeithertothefileregisterortheWREGregisterortobothinthecaseofsomeinstructions.Afewinstructionsoperatesolelyonafileregister(BSF,forexample).


TABLE:14-BITCOREBYTE-ORIENTEDFILEREGISTEROPERATIONS

Hex Mnemonic Description Function07df ADDWF f,d AddWandf W+f→d

05df ANDWF f,d ANDWandf W.AND.f→d

01'1'f CLRF f Clearf 0→f

01xx CLRW ClearW 0→W

09df COMF f,d Complementf .NOT.f→d

03df DECF f,d Decrementf f-1→d

0Bdf DECFSZ f,d Decrementf,skipifzero f-1→d,skipif0

0Adf INCF f,d Incrementf f+1→d

0Fdf INCFSZ f,d Incrementf,skipifzero f+1→d,skipif0

04df IORWF f,d InclusiveORWandf W.OR.f→d

08df MOVF f,d Movef f→d

00'1'f MOVWF f MoveWtof W→f

0000 NOP Nooperation

0Ddf RLF f,d Rotateleftf

0Cdf RRF f,d Rotaterightf

02df SUBWF f,d SubtractWfromf f-W→d

0Edf SWAPF f,d Swaphalvesf f(0:3)↔f(4:7)→d

06df XORWF f,d ExclusiveORWandf W.XOR.f→d


Hex Mnemonic Description Function4bf BCF f,b Bitclearf 0→f(b)

5bf BSF f,b Bitsetf 1→f(b)

6bf BTFSC f,b Bittest,skipifclear skipiff(b)=0

7bf BTFSS f,b Bittest,skipifset skipiff(b)=1

TABLE:14-BITCORELITERALANDCONTROLOPERATIONSHex Mnemonic Description Function

3Ekk ADDLW kk AddliteraltoW kk+WREG→WREG

39kk ANDLW kk ANDliteralandW kk.AND.WREG→WREG

2'0'kkk CALL kkk Callsubroutine PC+1→TOS,kk→PC

0064 CLRWDT Clearwatchdogtimer 0→WDT(andPrescalerifassigned)

2'1'kkk GOTO kkk Gotoaddress(kisninebits) kk→PC(9bits)

38kk IORLW kk Incl.ORliteralandW kk.OR.WREG→WREG

30kk MOVLW kk MoveLiteraltoW kk→WREG

0062 OPTION LoadOPTIONregister WREG→OPTIONRegister

0009 RETFIE ReturnfromInterrupt TOS→PC,1→GIE

34kk RETLW kk ReturnwithliteralinW kk→WREG,TOS→PC

0008 RETURN Returnfromsubroutine TOS→PC

0063 SLEEP GointoStandbyMode 0→WDT,stoposcillator

3Ckk SUBLW kk SubtractWfromliteral kk-WREG→WREG

006r TRIS r Tristateportr WREG→I/Ocontrolregr

3Akk XORLW kk ExclusiveORliteralandW kk.XOR.WREG→WREG

TABLE:12-BIT/14-BITCORESPECIALINSTRUCTIONMNEMONICS

Mnemonic Description EquivalentOperation(s) Status

BTFSC 3,0

ADDCF f,d AddCarrytoFile INCF f,d Z

ADDDCF f,d AddDigitCarrytoFile BTFSCINCF

3,1f,d Z

B k Branch GOTO k -

BC k BranchonCarry BTFSCGOTO

3,0k -

BDC k BranchonDigitCarry BTFSCGOTO

3,1k -

BNC k BranchonNoCarry BTFSSGOTO

3,0k -

BNDC k BranchonNoDigitCarry BTFSSGOTO

3,1k -

BNZ k BranchonNoZero BTFSSGOTO

3,2k -

BZ k BranchonZero BTFSCGOTO

3,2k -

CLRC ClearCarry BCF 3,0 -

CLRDC ClearDigitCarry BCF 3,1 -

CLRZ ClearZero BCF 3,2 -

LCALL k LongCallBCF/BSFBCF/BSFCALL

0x0A,30x0A,4k

LGOTO k LongGOTOBCF/BSFBCF/BSFGOTO

0x0A,30x0A,4k

MOVFW f MoveFiletoW MOVF f,0 Z

NEGF f,d NegateFile COMFINCF

f,1f,d Z

SETC SetCarry BSF 3,0 -

SETDC SetDigitCarry BSF 3,1 -

SETZ SetZero BSF 3,2 -

SKPC SkiponCarry BTFSS 3,0 -

SKPDC SkiponDigitCarry BTFSS 3,1 -

SKPNC SkiponNoCarry BTFSC 3,0 -

SKPNDC SkiponNoDigitCarry BTFSC 3,1 -

SKPNZ SkiponNonZero BTFSC 3,2 -

SKPZ SkiponZero BTFSS 3,2 -

SUBCF f,d SubtractCarryfromFile BTFSCDECF

3,0f,d Z

SUBDCF f,d SubtractDigitCarryfromFile BTFSC 3,1 Z



DECF f,dTSTF f TestFile MOVF f,1 Z




Microchip'shigh-performance8-bitmicrocontrollerfamilyusesa16-bitwideinstructionset.Thisinstructionsetconsistsof55instructions,eachasingle16-bitwideword.Mostinstructionsoperateonafileregister,f,andtheworkingregister,WREG(accumulator).TheresultcanbedirectedeithertothefileregisterortheWREGregisterortobothinthecaseofsomeinstructions.Somedevicesinthisfamilyalsoincludehardwaremultiplyinstructions.Afewinstructionsoperatesolelyonafileregister(BSFforexample).


TABLE:16-BITBYTE-ORIENTEDFILEREGISTEROPERATIONSHex Mnemonic Description Function0Ff* ADDWF f,d AddWREGtoF (WREG+f)→dest

11f* ADDWFC f,d AddWREGandCarrytof (WREG+f+C)→dest

0Bf* ANDWF f,d ANDWREGwithf (WREG.AND.f)→dest

29f* CLRF f,s Cleardest 0x00→dest

13f* COMF f,d Complementf .NOT.f→dest

31f CPFSEQ f Comparef,WREG,skipiff=WREG f-WREG,skipiff=WREG

32f CPFSGT f Comparef,WREG,skipiff>WREG f-WREG,skipiff>WREG

30f CPFSLT f Comparef,WREG,skipiff<WREG f-WREG,skipiff<WREG

2Ff* DAW f,s Dec.adjustWREG,storeindest WREGadjusted→dest

07f* DECF f,d Decrementf (f-1)→dest

17f* DECFSZ f,d Decrementf,skipif0 (f-1)→dest,skipif0

27f* DCFSNZ f,d Decrementf,skipifnot0 (f-1)→dest,skipifnot0

15f* INCF f,d Incrementf (f+1)→dest

1Ff* INCFSZ f,d Incrementf,skipifzero (f+1)→dest,skipif0

25f* INFSNZ f,d Incrementf,skipifnotzero (f+1)→dest,skipifnot0

09f* IORWF f,d InclusiveorWREGwithf (WREG.OR.f)→dest

6pf MOVFP f,p Moveftop f→p

4pf MOVPF p,f Moveptof p→f

01f MOVWF f MoveWREGtoF WREG→f

34f MULWF f MultiplyWREGandf (WREGxf)→PRODH:PRODL

2Df* NEGW f,s NegateWREG,storeindest -WREG→dest

0000 NOP Nooperation Nooperation

1Bf* RLCF f,d Rotateleftthroughcarry

23f* RLNCF f,d Rotateleft(nocarry)

19f* RRCF f,d Rotaterightthroughcarry

21f* RRNCF f,d Rotateright(nocarry)

2Af* SETF f,s Setdest 0xFF→dest

05f* SUBWF f,d SubtractWREGfromf (f-WREG)→d

03f* SUBWFB f,d Subtractfromfwithborrow (f-WREG-c)→d

1Df* SWAPF f,d Swapf f(0:3)→d(4:7),f(4:7)→d(0:3)

A8f TABLRD t,i,f

Readdatafromtablelatchintofilef,thenupdatetablelatchwith16-bitcontentsofmemorylocationaddressedbytablepointer

TBLATH→fift=1,TBLATL→fift=0;ProgMem(TBLPTR)→TBLAT;TBLPTR+1→TBLPTRifi=1

ACf TABLWT t,i,f

Writedatafromfileftotablelatchandthenwrite16-bittablelatchtoprogrammemorylocationaddressedbytablepointer

f→TBLATHift=1,f→TBLATLift=0;TBLAT→ProgMem(TBLPTR);TBLPTR+1→TBLPTRifi=1

A0f TLRD t,f Readdatafromtablelatchintofilef(tablelatchunchanged)

TBLATH→fift=1TBLATL→fift=0

A4f TLWT t,f Writedatafromfilefintotablelatch f→TBLATHift=1f→TBLATLift=0

33f TSTFSZ f Testf,skipifzero skipiff=0

0Df* XORWF f,d ExclusiveORWREGwithf (WREG.XOR.f)→dest

*Assumingdefaultbitvaluesfordands.


Hex Mnemonic Description Function8'1'bf BCF f,b Bitclearf 0→f(b)

8'0'bf BSF f,b Bitsetf 1→f(b)

9'1'bf BTFSC f,b Bittest,skipifclear skipiff(b)=0

9'0'bf BTFSS f,b Bittest,skipifset skipiff(b)=1

3'1'bf BTG f,b Bittogglef .NOT.f(b)→f(b)

TABLE:16-BITCORELITERALANDCONTROLOPERATIONSHex Mnemonic Description FunctionB1kk ADDLW kk AddliteraltoWREG (WREG+kk)→WREG

B5kk ANDLW kk ANDLiteralandWREG (WREG.AND.kk)→WREG

Ekkk CALL kkk Subroutinecall(within8kpage)PC+1→TOS,k→PC(12:0),k(12:8)→PCLATH(4:0),PC(15:13)→PCLATH(7:5)

0004 CLRWT Clearwatchdogtimer 0→WDT,0→WDTprescaler,1→PD,1→TO

Ckkk GOTO kkk Unconditionalbranch(within8k)k→PC(12:0)k(12:8)→PCLATH(4:0),PC(15:13)→PCLATH(7:5)

B3kk IORLW kk InclusiveORliteralwithW (WREG.OR.kk)→WREG

B7kk LCALL kk LongCall(within64k) (PC+1)→TOS;kk→PCL,(PCLATH)→PCH

B8xk MOVLB k MoveliteraltolownibbleinBSR k→BSR(3:0)

BAkx MOVLR k MoveliteraltohighnibbleinBSR k→BSR(7:4)

B0kk MOVLW kk MoveliteraltoWREG kk→WREG

BCkk MULLW kk MultiplyliteralandWREG (kkxWREG)→PRODH:PRODL

0005 RETFIE Returnfrominterrupt,enableinterrupt (PCLATH)→PCH:k→PCL0→GLINTD

B6kk RETLW kk ReturnwithliteralinWREG kk→W,TOS→PC,(PCLATHunchanged)

0002 RETURN Returnfromsubroutine TOS→PC(PCLATHunchanged)

0003 SLEEP EnterSleepModeStoposcillator,powerdown,0→WDT,0→WDTPrescaler1→PD,1→TO

B2kk SUBLW kk SubtractWREGfromliteral (kk-WREG)→WREG

B4kk XORLW kk ExclusiveORliteralwithWREG (WREG.XOR.kk)→WREG





KeytoExtended16-BitCoreInstructionSet

Field DescriptionRegisterFiles

dest DestinationeithertheWREGregisterorthespecifiedregisterfilelocation.Seed.

f

Registerfileaddress.f8-bit(0x00to0xFF).f'12-bit(0x000to0xFFF).Thisisthesourceaddress.f"12-bit(0x000to0xFFF).Thisisthedestinationaddress.

r 0,1or2forFSRnumber.

xDon'tcare(`0'or`1').Theassemblerwillgeneratecodewithx=0.ItistherecommendedformofuseforcompatibilitywithallMicrochipsoftwaretools.

Literals

k

Literalfield,constantdataorlabel.k4-bit.kk8-bit.kkk12-bit.

Offsets,Increments/Decrements

n Therelativeaddress(2'scomplementnumber)forrelativebranchinstructions,orthedirectaddressforCall/BranchandReturninstructions.

**+*-+*

ThemodeoftheTBLPTRregisterforthetablereadandtablewriteinstructions.Onlyusedwithtableread(TBLRD)andtablewrite(TBLWT)instructions:NoChangetoregisterPost-IncrementregisterPost-DecrementregisterPre-Incrementregister

Bits

aRAMaccessbita=0:RAMlocationinAccessRAM(BSRregisterisignored)a=1:RAMbankisspecifiedbyBSRregister(default)

b Bitaddresswithinan8-bitfileregister(0to7).

dDestinationselectbitd=0:storeresultinWREGd=1:storeresultinfileregisterf(default)

sFastCall/Returnmodeselectbits=0:donotupdateinto/fromshadowregisters(default)s=1:certainregistersloadedinto/fromshadowregisters(Fastmode)

'' Bitvalues,asopposedtoHexvalue.NamedRegistersBSR BankSelectRegister.UsedtoselectthecurrentRAMbank.FSR FileSelectRegister.PCL ProgramCounterLowByte.PCH ProgramCounterHighByte.

PCLATH ProgramCounterHighByteLatch.PCLATU ProgramCounterUpperByteLatch.PRODH ProductofMultiplyHighByte.PRODL ProductofMultiplyLowByte.STATUS StatusRegisterTABLAT 8-bitTableLatch.TBLPTR 21-bitTablePointer(pointstoaProgramMemorylocation).WREG Workingregister(accumulator).NamedBitsC,DC,Z,OV,N ALUStatusbits:Carry,DigitCarry,Zero,Overflow,Negative.

TO Time-outbit.PD Power-downbit.PEIE PeripheralInterruptEnablebit.GIE,GIEL/H GlobalInterruptEnablebit(s).

NamedDeviceFeaturesMCLR Mastercleardevicereset.PC ProgramCounter.TOS Top-of-Stack.WDT WatchdogTimer.Misc.Descriptors() Contents.→ Assignedto.<> Registerbitfield.





Extended16-BitCoreInstructionSet

Microchip'snewhigh-performance8-bitmicrocontrollerfamilyusesa16-bitwideinstructionset.Thisinstructionsetconsistsof76instructions,eachasingle16-bitwideword(2bytes).Mostinstructionsoperateonafileregister,f,andtheworkingregister,WREG(accumulator).TheresultcanbedirectedeithertothefileregisterortheWREGregisterortobothinthecaseofsomeinstructions.Afewinstructionsoperatesolelyonafileregister(BSFforexample).

TABLE:EXTENDED16-BITCOREBYTE-ORIENTEDREGISTEROPERATIONSHex Mnemonic Description Function27f* ADDWF f,d,a ADDWREGtof WREG+f→dest

23f* ADDWFC f,d,a ADDWREGandCarrybittof WREG+f+C→dest

17f* ANDWF f,d,a ANDWREGwithf WREG.AND.f→dest

6Bf* CLRF f,a Clearf 0→f

1Ff* COMF f,d,a Complementf .NOT.f→dest

63f* CPFSEQ f,a ComparefwithWREG,skipiff=WREG

f-WREG,iff=WREG,PC+4→PCelsePC+2→PC

65f* CPFSGT f,a ComparefwithWREG,skipiff>WREG

f-WREG,iff>WREG,PC+4→PCelsePC+2→PC

61f* CPFSLT f,a ComparefwithWREG,skipiff<WREG

f-WREG,iff<WREG,PC+4→PCelsePC+2→PC

07f* DECF f,d,a Decrementf f-1→dest

2Ff* DECFSZ f,d,a Decrementf,skipif0 f-1→dest,ifdest=0,PC+4→PCelsePC+2→PC

4Ff* DCFSNZ f,d,a Decrementf,skipifnot0 f-1→dest,ifdestÂ¼0,PC+4→PCelsePC+2→PC

2Bf* INCF f,d,a Incrementf f+1→dest

3Ff* INCFSZ f,d,a Incrementf,skipif0 f+1→dest,ifdest=0,PC+4→PCelsePC+2→PC

4Bf* INFSNZ f,d,a Incrementf,skipifnot0 f+1→dest,ifdestÂ¼0,PC+4→PCelsePC+2→PC

13f* IORWF f,d,a InclusiveORWREGwithf WREG.OR.f→dest

53f* MOVF f,d,a Movef f→dest

Cf'Ff" MOVFF f',f" Movef'tofd"(secondword) f'→f"

6Ff* MOVWF f,a MoveWREGtof WREG→f

03f* MULWF f,a MultiplyWREGwithf WREG*f→PRODH:PRODL

6Df* NEGF f,a Negatef -f→f

37f* RLCF f,d,a RotateleftfthroughCarry

47f* RLNCF f,d,a Rotateleftf(nocarry)

33f* RRCF f,d,a RotaterightfthroughCarry

43f* RRNCF f,d,a Rotaterightf(nocarry)

69f* SETF f,a Setf 0xFF→f

57f* SUBFWB f,d,a SubtractffromWREGwithBorrow WREG-f-C→dest

5Ff* SUBWF f,d,a SubtractWREGfromf f-WREG→dest

5Bf* SUBWFB f,d,a SubtractWREGfromfwithBorrow f-WREG-C→dest

3Bf* SWAPF f,d,a Swapnibblesoff f<3:0>→dest<7:4>,f<7:4>→dest<3:0>

67f* TSTFSZ f,a Testf,skipif0 PC+4→PC,iff=0,elsePC+2→PC

1Bf* XORWF f,d,a ExclusiveORWREGwithf WREG.XOR.f→dest*Assumingdefaultbitvaluesfordanda.

TABLE:EXTENDED16-BITCOREBIT-ORIENTEDREGISTEROPERATIONS

Hex Mnemonic Description Function91f* BCF f,b,a BitClearf 0→f

81f* BSF f,b,a BitSetf 1→f

B1f* BTFSC f,b,a Bittestf,skipifclear iff=0,PC+4→PC,elsePC+2→PC

A1f* BTFSS f,b,a Bittestf,skipifset iff=1,PC+4→PC,elsePC+2→PC

71f* BTG f,b,a BitTogglef f→f*Assumingb=0anddefaultbitvaluefora.

TABLE:EXTENDED16-BITCORECONTROLOPERATIONSHex Mnemonic Description Function

E2n BC n BranchifCarry ifC=1,PC+2+2*n→PC,elsePC+2→PC

E6n BN n BranchifNegative ifN=1,PC+2+2*n→PC,elsePC+2→PC

E3n BNC n BranchifNotCarry ifC=0,PC+2+2*n→PC,elsePC+2→PC

E7n BNN n BranchifNotNegative ifN=0,PC+2+2*n→PC,elsePC+2→PC

E5n BNOV n BranchifNotOverflow ifOV=0,PC+2+2*n→PC,elsePC+2→PC

E1n BNZ n BranchifNotZero ifZ=0,PC+2+2*n→PC,elsePC+2→PC

E4n BOV n BranchifOverflow ifOV=1,PC+2+2*n→PC,elsePC+2→PC

D'0'n BRA n BranchUnconditionally PC+2+2*n→PC

E0n BZ n BranchifZero ifZ=1,PC+2+2*n→PC,elsePC+2→PC

ECkk*Fkkk CALL n,s CallSubroutine1stword

2ndword

PC+4→TOS,n→PC<20:1>,ifs=1,WREG→WREGs,STATUS→STATUSs,BSR→BSRs

0004 CLRWDT ClearWatchdogTimer 0→WDT,0→WDTpostscaler,1→TO,1→PD

0007 DAW DecimalAdjustWREG

ifWREG<3:0>>9orDC=1,WREG<3:0>+6→WREG<3:0>,elseWREG<3:0>→WREG<3:0>;ifWREG<7:4>>9orC=1,WREG<7:4>+6→WREG<7:4>,elseWREG<7:4>→WREG<7:4>;

EFkkFkkk GOTO n Gotoaddress1stword

2ndword n→PC<20:1>

0000 NOP NoOperation NoOperation

Fxxx NOP NoOperation NoOperation(2-wordinstructions)

0006 POP Poptopofreturnstack(TOS) TOS-1→TOS

0005 PUSH Pushtopofreturnstack(TOS) PC+2→TOS

D'1'n RCALL n RelativeCall PC+2→TOS,PC+2+2*n→PC

00FF RESET Softwaredevicereset SameasMCLRreset

0010* RETFIE s Returnfrominterrupt(andenableinterrupts)

TOS→PC,1→GIE/GIEHorPEIE/GIEL,ifs=1,WREGs→WREG,STATUSs→STATUS,BSRs→BSR,PCLATU/PCLATHunchngd.

0012* RETURN s ReturnfromsubroutineTOS→PC,ifs=1,WREGs→WREG,STATUSs→STATUS,BSRs→BSR,PCLATU/PCLATHareunchanged

0003 SLEEP EnterSLEEPMode 0→WDT,0→WDTpostscaler,1→TO,0→PD

*Assumingdefaultbitvaluefors.

TABLE:EXTENDED16-BITCORELITERALOPERATIONSHex Mnemonic Description Function0Fkk ADDLW kk AddliteraltoWREG WREG+kk→WREG

0Bkk ANDLW kk ANDliteralwithWREG WREG.AND.kk→WREG

09kk IORLW kk InclusiveORliteralwithWREG WREG.OR.kk→WREG

EErkF0kk LFSR r,kk Moveliteral(12bit)2ndword

toFSRr1stword kk→FSRr

010k MOVLB k MoveliteraltoBSR<3:0> kk→BSR

0Ekk MOVLW kk MoveliteraltoWREG kk→WREG



0Dkk MULLW kk MultiplyliteralwithWREG WREG*kk→PRODH:PRODL

0Ckk RETLW kk ReturnwithliteralinWREG kk→WREG

08kk SUBLW kk SubtractWREGfromliteral kk-WREG→WREG

0Akk XORLW kk ExclusiveORliteralwithWREG WREG.XOR.kk→WREG

TABLE:EXTENDED16-BITCOREMEMORYOPERATIONSHex Mnemonic Description Function0008 TBLRD* TableRead ProgMem(TBLPTR)→TABLAT

0009 TBLRD*+ TableReadwithpost-increment ProgMem(TBLPTR)→TABLATTBLPTR+1→TBLPTR

000A TBLRD*- TableReadwithpost-decrement ProgMem(TBLPTR)→TABLATTBLPTR-1→TBLPTR

000B TBLRD+* TableReadwithpre-increment TBLPTR+1→TBLPTRProgMem(TBLPTR)→TABLAT

000C TBLWT* TableWrite TABLAT→ProgMem(TBLPTR)

000D TBLWT*+ TableWritewithpost-increment TABLAT→ProgMem(TBLPTR)TBLPTR+1→TBLPTR

000E TBLWT*- TableWritewithpost-decrement TABLAT→ProgMem(TBLPTR)TBLPTR-1→TBLPTR

000F TBLWT+* TableWritewithpre-increment TBLPTR+1→TBLPTRTABLAT→ProgMem(TBLPTR)





UsefulTables

Someusefultablesareincludedforreferencehere.

ASCIICharacterSet

HexadecimaltoDecimalConversion



ASCIICharacterSet

LeastSignificantNibble

MostSignificantNibbleHEX 0 1 2 3 4 5 6 70 NUL DLE Space 0 @ P ` p1 SOH DC1 ! 1 A Q a q2 STX DC2 " 2 B R b r3 ETX DC3 # 3 C S c s4 EOT DC4 $ 4 D T d t5 ENQ NAK % 5 E U e u6 ACK SYN & 6 F V f v7 Bell ETB ' 7 G W g w8 BS CAN ( 8 H X h x9 HT EM ) 9 I Y i yA LF SUB * : J Z j zB VT ESC + ; K [ k {C FF FS , < L \ l |D CR GS - = M ] m }E SO RS . > N ^ n ~F SI US / ? O _ o DEL







HexadecimaltoDecimalConversion

Thisappendixdescribeshowtoconverthexadecimaltodecimal.ForeachHEXdigit,findtheassociateddecimalvalue.Addthenumberstogether.

HighByte LowByteHEX1000 Dec HEX100 Dec HEX10 Dec HEX1 Dec

0 0 0 0 0 0 0 01 4096 1 256 1 16 1 12 8192 2 512 2 32 2 23 12288 3 768 3 48 3 34 16384 4 1024 4 64 4 45 20480 5 1280 5 80 5 56 24576 6 1536 6 96 6 67 28672 7 1792 7 112 7 78 32768 8 2048 8 128 8 89 36864 9 2304 9 144 9 9A 40960 A 2560 A 160 A 10B 45056 B 2816 B 176 B 11C 49152 C 3072 C 192 C 12D 53248 D 3328 D 208 D 13E 57344 E 3584 E 224 E 14F 61440 F 3840 F 240 F 15

Forexample,HEXA38Fconvertsto41871asfollows:

HEX1000'sDigit HEX100'sDigit HEX10'sDigit HEX1'sDigit Result

40960 768 128 15 41871Decimal





Support

ThegeneralinformationcontainedherewillbeusefultoknowwhenworkingwithMicrochipTechnology'sMPASMassembler(theassembler),MPLINKobjectlinker(thelinker),andMPLIBobjectlibrarian(thelibrarian).

RecommendedReading

TheMicrochipWebSiteDevelopmentSystemsCustomerNotificationServiceCustomerSupport



RecommendedReading

Otherusefuldocumentsarelistedbelow.

ReadmeFile-readme.asm

ForthelatestinformationonusingMPASMassembler,readthereadme.asmfile(anASCIItextfile)intheMPLABIDEdirectory.TheREADMEfilecontainsupdateinformationandknownissuesthatmaynotbeincludedintheuser'sguideortheon-linehelpfile.

ReadmeFile-readme.lkr

ForthelatestinformationonusingMPLINKlinkerandMPLIBlibrarian,readthereadme.lkrfile(anASCIItextfile)intheMPLABIDEdirectory.TheREADMEfilecontainsupdateinformationandknownissuesthatmaynotbeincludedintheuser'sguideortheon-linehelpfile.

MPASMAssembler,MPLINKObjectLinker,andMPLIBObjectLibrarianUser'sGuide(DS00000)

Thisuser'sguidedescribeshowtousetheMicrochipPICmicroMCUMPASMassembler,MPLINKobjectlinkerandMPLIBobjectlibrarian.

MPASMandMPLINKPICmicroQuickReferenceCard(DS30400)

Aquickreferencecard(QRC)containingMPASMassemblerdirectivelanguagesummary,MPASMassemblerradixtypessupported,MPLINKobjectlinkercommandlineoptions,MPLIBobjectlibrarianusageformatandexamples,PIC18CXXXcorespecialfunctionregisterfiles,ASCIIcharacterset,andPICmicroMCUinstructionsetsummaries.



MicrochipTechnicalLibraryCD-ROM(DS00161)

ThisCD-ROMcontainscomprehensiveapplicationnotes,datasheets,andtechnicalbriefsforallofMicrochipproducts.ToobtainthisCD-ROM,contactthenearestMicrochipSalesandServicelocation(seebackpage).

EmbeddedControlHandbookVol.1&2andtheEmbeddedControlHandbookUpdate2000(DS00092,DS00167,andDS00711)

Thesehandbookscontainawealthofinformationaboutmicrocontrollerapplications.Toobtainthesedocuments,contactthenearestMicrochipsalesandservicelocation(seebackpage).

TheapplicationnotesdescribedinthesemanualsarealsoobtainablefromMicrochipsalesandservicelocationsorfromtheMicrochipwebsite(http://www.microchip.com).

Microsoft®Windows®Manuals

ThismanualassumesthatusersarefamiliarwiththeMicrosoftWindowsoperatingsystem.Manyexcellentreferencesexistforthissoftwareprogram,andshouldbeconsultedforgeneraloperationofWindows.



TheMicrochipWebSite

MicrochipprovidesonlinesupportontheMicrochipWorldWideWeb(WWW)site.ThewebsiteisusedbyMicrochipasameanstomakefilesandinformationeasilyavailabletocustomers.Toviewthesite,youmusthaveaccesstotheInternetandawebbrowsersuchasNetscapeNavigatororMicrosoftInternetExplorer.

TheMicrochipwebsiteisavailablebyusingyourfavoriteInternetbrowsertoattachto:


Thewebsiteprovidesavarietyofservices.Usersmaydownloadfilesforthelatestdevelopmenttools,datasheets,applicationnotes,user'sguides,articles,andsampleprograms.AvarietyinformationspecifictothebusinessofMicrochipisalsoavailable,includinglistingsofMicrochipsalesoffices,distributorsandfactoryrepresentatives.

TechnicalSupport

FrequentlyAskedQuestions(FAQ)

OnlineDiscussionGroups-Conferencesforproducts,DevelopmentSystems,technicalinformationandmoreMicrochipConsultantProgramMemberListingLinkstootherusefulwebsitesrelatedtoMicrochipproducts

Developer'sToolbox

DesignTips

DeviceErrata

Otheravailableinformation



LatestMicrochipPressReleases

ListingofseminarsandeventsJobPostings



DevelopmentSystemsCustomerNotificationService

MicrochipstartedthecustomernotificationservicetohelpourcustomerskeepcurrentonMicrochipproductswiththeleastamountofeffort.Onceyousubscribe,youwillreceiveemailnotificationwheneverwechange,update,reviseorhaveerratarelatedtoyourspecifiedproductfamilyordevelopmenttoolofinterest.

GototheMicrochipWWWwebpage(http://www.microchip.com)andclickonCustomerChangeNotificationunderItemsofInterest.Followtheinstructionstoregister.

TheDevelopmentSystemsproductgroupcategoriesare:

Compilers

EmulatorsIn-CircuitDebuggersMPLABProgrammers

Hereisadescriptionofthesecategories:

COMPILERS-ThelatestinformationonMicrochipCcompilersandotherlanguagetools.TheseincludetheMPLABC17,MPLABC18andMPLABC30Ccompilers;MPASMandMPLABASM30assemblers;MPLINKandMPLABLINK30objectlinkers;andMPLIBandMPLABLIB30objectlibrarians.

EMULATORS-ThelatestinformationonMicrochipin-circuitemulators.ThisincludestheMPLABICE2000andMPLABICE4000.



IN-CIRCUITDEBUGGERS-ThelatestinformationonMicrochipin-circuitdebuggers.TheseincludetheMPLABICDandMPLABICD2.

MPLAB-ThelatestinformationonMicrochipMPLABIDE,theWindowsIntegratedDevelopmentEnvironmentfordevelopmentsystemstools.ThislistisfocusedontheMPLABIDE,MPLABSIMandMPLABSIM30simulators,MPLABIDEProjectManagerandgeneraleditinganddebuggingfeatures.

PROGRAMMERS-ThelatestinformationonMicrochipdeviceprogrammers.TheseincludethePROMATEIIdeviceprogrammerandPICSTARTPlusdevelopmentprogrammer.





CustomerSupport

UsersofMicrochipproductscanreceiveassistancethroughseveralchannels:

DistributororRepresentative

LocalSalesOfficeFieldApplicationEngineer(FAE)CorporateApplicationsEngineer(CAE)Hotline

Customersshouldcalltheirdistributor,representativeorfieldapplicationengineer(FAE)forsupport.Localsalesofficesarealsoavailabletohelpcustomers.Seethebackcoverforalistingofsalesofficesandlocations.

CorporateApplicationsEngineers(CAEs)maybecontactedat(480)792-7627.

Inaddition,thereisaSystemsInformationandUpgradeLine.ThislineprovidessystemusersalistingofthelatestversionsofallofMicrochip'sdevelopmentsystemssoftwareproducts.Plus,thislineprovidesinformationonhowcustomerscanreceiveanycurrentlyavailableupgradekits.

TheHotlineNumbersare:

1-800-755-2345forU.S.andmostofCanada.

1-480-792-7302fortherestoftheworld.



Glossary

AbsoluteSection

Asectionwithafixed(absolute)addressthatcannotbechangedbythelinker.

AccessMemory(PIC18Only)

SpecialregistersonPIC18XXXXXdevicesthatallowaccessregardlessofthesettingofthebankselectregister(BSR).

Address

Valuethatidentifiesalocationinmemory.

AlphabeticCharacter

Alphabeticcharactersarethosecharactersthatarelettersofthearabicalphabet(a,b,...,z,A,B,...,Z).

Alphanumeric

Alphanumericcharactersarecomprisedofalphabeticcharactersanddecimaldigits(0,1,...,9).

AnonymousStructure

AnunnamedstructurethatisamemberofaCunion.Themembersofananonymousstructuremaybeaccessedasiftheyweremembersoftheenclosingunion.Forexample,inthefollowingcode,hiandloaremembersofananonymousstructureinsidetheunioncaster.

unioncastawayintintval;

struct{charlo;//accessibleascaster.locharhi;//accessibleascaster.hi};}caster;ANSI

AmericanNationalStandardsInstituteisanorganizationresponsibleforformulatingandapprovingstandardsintheUnitedStates.

Application

AsetofsoftwareandhardwarethatmaybecontrolledbyaPICmicromicrocontroller.

Archive

Acollectionofrelocatableobjectmodules.Itiscreatedbyassemblingmultiplesourcefilestoobjectfiles,andthenusingthearchivertocombinetheobjectfilesintoonelibraryfile.Alibrarycanbelinkedwithobjectmodulesandotherlibrariestocreateexecutablecode.

Archiver

Atoolthatcreatesandmanipulateslibraries.

ASCII

AmericanStandardCodeforInformationInterchangeisacharactersetencodingthatuses7binarydigitstorepresenteachcharacter.Itincludesupperandlowercaseletters,digits,symbolsandcontrolcharacters.

Assembler

Alanguagetoolthattranslatesassemblylanguagesourcecode

intomachinecode.

AssemblyLanguage

Aprogramminglanguagethatdescribesbinarymachinecodeinasymbolicform.

AssignedSection

Asectionwhichhasbeenassignedtoatargetmemoryblockinthelinkercommandfile.

AsynchronousEvents

Multipleeventsthatdonotoccuratthesametime.Thisisgenerallyusedtorefertointerruptsthatmayoccuratanytimeduringprocessorexecution.

AsynchronousStimulus

Datageneratedtosimulateexternalinputstoasimulatordevice.

Binary

Thebasetwonumberingsystemthatusesthedigits0-1.Theright-mostdigitcountsones,thenextcountsmultiplesof2,then22=4,etc.

Breakpoint,Hardware

Aneventwhoseexecutionwillcauseahalt.

Breakpoint,Software

Anaddresswhereexecutionofthefirmwarewillhalt.Usuallyachievedbyaspecialbreakinstruction.

Build

Compileandlinkallthesourcefilesforanapplication.

C

Ageneral-purposeprogramminglanguagewhichfeatureseconomyofexpression,moderncontrolflowanddatastructures,andarichsetofoperators.

CalibrationMemory

AspecialfunctionregisterorregistersusedtoholdvaluesforcalibrationofaPICmicromicrocontrolleron-boardRCoscillatororotherdeviceperipherals.

CentralProcessingUnit

Thepartofadevicethatisresponsibleforfetchingthecorrectinstructionforexecution,decodingthatinstruction,andthenexecutingthatinstruction.Whennecessary,itworksinconjunctionwiththearithmeticlogicunit(ALU)tocompletetheexecutionoftheinstruction.Itcontrolstheprogrammemoryaddressbus,thedatamemoryaddressbus,andaccessestothestack.

COFF

CommonObjectFileFormat.Anobjectfileofthisformatcontainsmachinecode,debuggingandotherinformation.


Ameansofcommunicationbetweenaprogramanditsuserbasedsolelyontextualinputandoutput.

Compiler

Aprogramthattranslatesasourcefilewritteninahigh-levellanguageintomachinecode.

ConditionalCompilation

Theactofcompilingaprogramfragmentonlyifacertainconstantexpression,specifiedbyapreprocessordirective,istrue.

ConfigurationBits

Special-purposebitsprogrammedtosetPICmicromicrocontrollermodesofoperation.Aconfigurationbitmayormaynotbepreprogrammed.

ControlDirectives

Directivesinassemblylanguagecodethatcausecodetobeincludedoromittedbasedontheassembly-timevalueofaspecifiedexpression.

CPU

SeeCentralProcessingUnit.

CrossReferenceFile

Afilethatreferencesatableofsymbolsandalistoffilesthatreferencesthesymbol.Ifthesymbolisdefined,thefirstfilelistedisthelocationofthedefinition.Theremainingfilescontainreferencestothesymbol.

DataDirectives

Datadirectivesarethosethatcontroltheassembler'sallocationofprogramordatamemoryandprovideawaytorefertodataitemssymbolically;thatis,bymeaningfulnames.

DataMemory

OnMicrochipMCUandDSCdevices,datamemory(RAM)iscomprisedofgeneralpurposeregisters(GPRs)andspecial

functionregisters(SFRs).SomedevicesalsohaveEEPROMdatamemory.

DeviceProgrammer

Atoolusedtoprogramelectricallyprogrammablesemiconductordevicessuchasmicrocontrollers.

Directives

Statementsinsourcecodethatprovidecontrolofthelanguagetool'soperation.

Download

Downloadistheprocessofsendingdatafromahosttoanotherdevice,suchasanemulator,programmerortargetboard.

EEPROM

ElectricallyErasableProgrammableReadOnlyMemory.AspecialtypeofPROMthatcanbeerasedelectrically.Dataiswrittenorerasedonebyteatatime.EEPROMretainsitscontentsevenwhenpoweristurnedoff.

Emulation

Theprocessofexecutingsoftwareloadedintoemulationmemoryasifitwerefirmwareresidingonamicrocontrollerdevice.

EmulationMemory

Programmemorycontainedwithintheemulator.

Emulator

Hardwarethatperformsemulation.

EmulatorSystem

TheMPLABICE2000and4000emulatorsystemsincludethepod,processormodule,deviceadapter,cables,andMPLABIDEsoftware.

Endianess

Describesorderofbytesinamulti-byteobject.

EPROM

ErasableProgrammableReadOnlyMemory.Aprogrammableread-onlymemorythatcanbeerasedusuallybyexposuretoultravioletradiation.

ErrorFile

Afilecontainingerrormessagesanddiagnosticsgeneratedbyalanguagetool.

Event

Adescriptionofabuscyclewhichmayincludeaddress,data,passcount,externalinput,cycletype(fetch,R/W),andtimestamp.Eventsareusedtodescribetriggers,breakpointsandinterrupts.

Export

SenddataoutoftheMPLABIDEinastandardizedformat.

ExtendedMicrocontrollerMode

Inextendedmicrocontrollermode,on-chipprogrammemoryaswellasexternalmemoryisavailable.ExecutionautomaticallyswitchestoexternaliftheprogrammemoryaddressisgreaterthantheinternalmemoryspaceofthePIC17CXXXorPIC18CXXXdevice.

ExternalLabel

Alabelthathasexternallinkage.

ExternalLinkage

Afunctionorvariablehasexternallinkageifitcanbereferencedfromoutsidethemoduleinwhichitisdefined.

ExternalSymbol

Asymbolforanidentifierwhichhasexternallinkage.Thismaybeareferenceoradefinition.

ExternalSymbolResolution

Aprocessperformedbythelinkerinwhichexternalsymboldefinitionsfromallinputmodulesarecollectedinanattempttoresolveallexternalsymbolreferences.Anyexternalsymbolreferenceswhichdonothaveacorrespondingdefinitioncausealinkererrortobereported.

ExternalInputLine

Anexternalinputsignallogicprobeline(TRIGIN)forsettinganeventbaseduponexternalsignals.

ExternalRAM

Off-chipRead/Writememory.

FileRegisters

On-chipdatamemory,includinggeneralpurposeregisters(GPRs)andspecialfunctionregisters(SFRs).

Flash

AtypeofEEPROMwheredataiswrittenorerasedinblocksinsteadofbytes.

FNOP

ForcedNoOperation.AforcedNOPcycleisthesecondcycleofatwo-cycleinstruction.SincethePICmicromicrocontrollerarchitectureispipelined,itprefetchesthenextinstructioninthephysicaladdressspacewhileitisexecutingthecurrentinstruction.However,ifthecurrentinstructionchangestheprogramcounter,thisprefetchedinstructionisexplicitlyignored,causingaforcedNOPcycle.

FramePointer

Apointerthatreferencesthelocationonthestackthatseparatesthestack-basedargumentsfromthestack-basedlocalvariables.Providesaconvenientbasefromwhichtoaccesslocalvariablesandothervaluesforthecurrentfunction.

Free-Standing

ACcompilerimplementationthatacceptsanystrictlyconformingprogramthatdoesnotusecomplextypesandinwhichtheuseofthefeaturesspecifiedintheISOlibraryclauseisconfinedtothecontentsofthestandardheaders<float.h>,<iso646.h>,<limits.h>,<stddef.h>,and<stdint.h>.

GPR

GeneralPurposeRegister.Theportionofdevicedatamemory(RAM)avaliableforgeneraluse.

Halt

Astopofprogramexecution.ExecutingHaltisthesameasstoppingatabreakpoint.

HEXCode

Executableinstructionsstoredinahexadecimalformatcode.HEX

codeiscontainedinaHEXfile.

HEXFile

AnASCIIfilecontaininghexadecimaladdressesandvalues(HEXcode)suitableforprogrammingadevice.

Hexadecimal

Thebase16numberingsystemthatusesthedigits0-9plusthelettersA-F(ora-f).ThedigitsA-Frepresenthexadecimaldigitswithvaluesof(decimal)10to15.Theright-mostdigitcountsones,thenextcountsmultiplesof16,then162=256,etc.

HighLevelLanguage

Alanguageforwritingprogramsthatisfurtherremovedfromtheprocessorthanassembly.

ICD

In-CircuitDebugger.MPLABICDandMPLABICD2areMicrochip'sin-circuitdebuggersforPIC16F87XandPIC18FXXXdevices,respectively.TheseICDsworkwithMPLABIDE.

ICE

In-CircuitEmulator.MPLABICE2000and4000areMicrochip'sin-circuitemulatorsthatworkwithMPLABIDE.

IDE

IntegratedDevelopmentEnvironment.MPLABIDEisMicrochip'sintegrateddevelopmentenvironment.

IEEE

InstituteofElectricalandElectronicsEngineers.

Import

BringdataintotheMPLABIDEfromanoutsidesource,suchasfromaHEXfile.

InstructionSet

Thecollectionofmachinelanguageinstructionsthataparticularprocessorunderstands.

Instructions

Asequenceofbitsthattellsacentralprocessingunittoperformaparticularoperationandcancontaindatatobeusedintheoperation.

InternalLinkage

Afunctionorvariablehasinternallinkageifitcannotbeaccessedfromoutsidethemoduleinwhichitisdefined.

InternationalOrganizationforStandardization

Anorganizationthatsetsstandardsinmanybusinessesandtechnologies,includingcomputingandcommunications.

Interrupt

AsignaltotheCPUthatsuspendstheexecutionofarunningapplicationandtransferscontroltoanInterruptServiceRoutine(ISR)sothattheeventmaybeprocessed.

InterruptHandler

Aroutinethatprocessesspecialcodewhenaninterruptoccurs.

InterruptRequest

Aneventwhichcausestheprocessortotemporarilysuspend

normalinstructionexecutionandtostartexecutinganinterrupthandlerroutine.Someprocessorshaveseveralinterruptrequesteventsallowingdifferentpriorityinterrupts.

InterruptServiceRoutine

Afunctionthatisinvokedwhenaninterruptoccurs.

InterruptServiceRoutine

User-generatedcodethatisenteredwhenaninterruptoccurs.Thelocationofthecodeinprogrammemorywillusuallydependonthetypeofinterruptthathasoccurred.

IRQ

SeeInterruptRequest.

ISO

SeeInternationalOrganizationforStandardization.

ISR

SeeInterruptServiceRoutine.

Latency

Thetimebetweenaneventanditsresponse.

Librarian

SeeArchiver.

Library

SeeArchive.

Linker

Alanguagetoolthatcombinesobjectfilesandlibrariestocreateexecutablecode,resolvingreferencesfromonemoduletoanother.

LinkerScriptFiles

Linkerscriptfilesarethecommandfilesofalinker.Theydefinelinkeroptionsanddescribeavailablememoryonthetargetplatform.

ListingDirectives

Listingdirectivesarethosedirectivesthatcontroltheassemblerlistingfileformat.Theyallowthespecificationoftitles,paginationandotherlistingcontrol.

ListingFile

AlistingfileisanASCIItextfilethatshowsthemachinecodegeneratedforeachCsourcestatement,assemblyinstruction,assemblerdirective,ormacroencounteredinasourcefile.

LittleEndianess

Adataorderingschemeformultibytedatawherebytheleastsignificantbyteisstoredattheloweraddresses.

LocalLabel

AlocallabelisonethatisdefinedinsideamacrowiththeLOCALdirective.Theselabelsareparticulartoagiveninstanceofamacro'sinstantiation.Inotherwords,thesymbolsandlabelsthataredeclaredaslocalarenolongeraccessibleaftertheENDMmacroisencountered.

LogicProbes

Upto14logicprobescanbeconnectedtosomeMicrochipemulators.Thelogicprobesprovideexternaltraceinputs,trigger

outputsignal,+5V,andacommonground.

MachineCode

Therepresentationofacomputerprogramthatisactuallyreadandinterpretedbytheprocessor.Aprograminbinarymachinecodeconsistsofasequenceofmachineinstructions(possiblyinterspersedwithdata).Thecollectionofallpossibleinstructionsforaparticularprocessorisknownasits"instructionset".

MachineLanguage

Asetofinstructionsforaspecificcentralprocessingunit,designedtobeusablebyaprocessorwithoutbeingtranslated.

Macro

Macroinstruction.Aninstructionthatrepresentsasequenceofinstructionsinabbreviatedform.

MacroDirectives

Directivesthatcontroltheexecutionanddataallocationwithinmacrobodydefinitions.

MakeProject

Acommandthatrebuildsanapplication,re-compilingonlythosesourcefilesthathavechangedsincethelastcompletecompilation.

MCU

MicrocontrollerUnit.Anabbreviationformicrocontroller.AlsouC.

MemoryModels

Versionsoflibrariesand/orprecompiledobjectfilesbasedonadevice'smemory(RAM/ROM)sizeandstructure.

MemoryModels

Adescriptionthatspecifiesthesizeofpointersthatpointtoprogrammemory.

Message

Textdisplayedtoalertyoutopotentialproblemsinlanguagetooloperation.Amessagewillnotstopoperation.

Microcontroller

AhighlyintegratedchipthatcontainsaCPU,RAM,programmemory,I/Oports,andtimers.

MicrocontrollerMode

OneofthepossibleprogrammemoryconfigurationsofthePIC17CXXXandPIC18CXXXfamiliesofmicrocontrollers.Inmicrocontrollermode,onlyinternalexecutionisallowed.Thus,onlytheon-chipprogrammemoryisavailableinmicrocontrollermode.

MicroprocessorMode

OneofthepossibleprogrammemoryconfigurationsofthePIC17CXXXandPIC18CXXXfamiliesofmicrocontrollers.Inmicroprocessormode,theon-chipprogrammemoryisnotused.Theentireprogrammemoryismappedexternally.

Mnemonics

Textinstructionsthatcanbetranslateddirectlyintomachinecode.AlsoreferredtoasOpcodes.

MPASMAssembler

MicrochipTechnology'srelocatablemacroassemblerforPICmicromicrocontrollerdevices,KeeLoqdevicesandMicrochipmemory

devices.

MPLABASM30

Microchip'srelocatablemacroassemblerfordsPIC30Fdigitialsignalcontrollerdevices.

MPLABC1X

ReferstoboththeMPLABC17andMPLABC18CcompilersfromMicrochip.MPLABC17istheCcompilerforPIC17CXXXdevicesandMPLABC18istheCcompilerforPIC18CXXXandPIC18FXXXXdevices.

MPLABC30

Microchip'sCcompilerfordsPIC30Fdigitialsignalcontrollerdevices.

MPLABICD2

Microchip'sin-circuitdebuggerforPIC16F87X,PIC18FXXXanddsPIC30FXXXXdevices.TheICDworkswithMPLABIDE.ThemaincomponentofeachICDisthemodule.Acompletesystemconsistsofamodule,header,demoboard,cables,andMPLABIDESoftware.

MPLABICE2000

Microchip'sin-circuitemulatorforPICmicroMCU'sthatworkswithMPLABIDE.

MPLABICE4000

Microchip'sin-circuitemulatorfordsPICDSC'sthatworkswithMPLABIDE.

MPLABIDE

Microchip'sIntegratedDevelopmentEnvironment.

MPLABLIB30

MPLABLIB30archiver/librarianisanobjectlibrarianforusewithCOFFobjectmodulescreatedusingeitherMPLABASM30orMPLABC30Ccompiler.

MPLABLINK30

MPLABLINK30isanobjectlinkerfortheMicrochipMPLABASM30assemblerandtheMicrochipMPLABC30Ccompiler.

MPLABSIM

Microchip'ssimulatorthatworkswithMPLABIDEinsupportofPICmicroMCUdevices.

MPLABSIM30

Microchip'ssimulatorthatworkswithMPLABIDEinsupportofdsPICDSCdevices.

MPLIBObjectLibrarian

MPLIBlibrarianisanobjectlibrarianforusewithCOFFobjectmodulescreatedusingeitherMPASMassembler(mpasmormpasmwinv2.0)orMPLABC1XCcompilers.

MPLINKObjectLinker

MPLINKlinkerisanobjectlinkerfortheMicrochipMPASMassemblerandtheMicrochipMPLABC17orC18Ccompilers.MPLINKlinkeralsomaybeusedwiththeMicrochipMPLIBlibrarian.MPLINKlinkerisdesignedtobeusedwithMPLABIDE,thoughitdoesnothavetobe.

MRU

MostRecentlyUsed.ReferstofilesandwindowsavailabletobeselectedfromMPLABIDEmainpulldownmenus.

NestingDepth

Themaximumleveltowhichmacroscanincludeothermacros.

Node

MPLABIDEprojectcomponent.

NonReal-Time

ReferstotheprocessoratabreakpointorexecutingsinglestepinstructionsorMPLABIDEbeingruninsimulatormode.

Non-VolatileStorage

Astoragedevicewhosecontentsarepreservedwhenitspowerisoff.

NOP

NoOperation.Aninstructionthathasnoeffectwhenexecutedexcepttoadvancetheprogramcounter.

ObjectCode

Themachinecodegeneratedbyanassemblerorcompiler.

ObjectFile

Afilecontainingmachinecodeandpossiblydebuginformation.Itmaybeimmediatelyexecutableoritmayberelocatable,requiringlinkingwithotherobjectfiles,e.g.libraries,toproduceacompleteexecutableprogram.

ObjectFileDirectives

Directivesthatareusedonlywhencreatinganobjectfile.

Octal

Thebase8numbersystemthatonlyusesthedigits0-7.Theright-mostdigitcountsones,thenextdigitcountsmultiplesof8,then8^2=64,etc.

Off-ChipMemory

Off-chipmemoryreferstothememoryselectionoptionforthePIC17CXXXorPIC18CXXXdevicewherememorymayresideonthetargetboard,orwhereallprogrammemorymaybesuppliedbytheEmulator.TheMemorytabaccessedfromOptions>DevelopmentModeprovidestheOff-ChipMemoryselectiondialogbox.

Opcodes

OperationalCodes.SeeMnemonics.

Operators

Symbols,liketheplussign`+'andtheminussign`-',thatareusedwhenformingwell-definedexpressions.Eachoperatorhasanassignedprecedencethatisusedtodetermineorderofevaluation.

OTP

OneTimeProgrammable.EPROMdevicesthatarenotinwindowedpackages.SinceEPROMneedsultravioletlighttoeraseitsmemory,onlywindoweddevicesareerasable.

PassCounter

Acounterthatdecrementseachtimeanevent(suchastheexecutionofaninstructionataparticularaddress)occurs.Whenthepasscountvaluereacheszero,theeventissatisfied.Youcan

assignthePassCountertobreakandtracelogic,andtoanysequentialeventinthecomplextriggerdialog.

PC

PersonalComputerorProgramCounter.

PCHost

AnyIBM™orcompatiblepersonalcomputerrunningasupportedWindowsoperatingsystem.

PICmicroMCUs

PICmicromicrocontrollers(MCUs)referstoallMicrochipmicrocontrollerfamilies.

PICSTARTPlus

AdevelopmentaldeviceprogrammerfromMicrochip.Programs8-,14-,28-,and40-pinPICmicromicrocontrollers.MustbeusedwithMPLABIDESoftware.

Pod,Emulator

Theexternalemulatorboxthatcontainsemulationmemory,tracememory,eventandcycletimers,andtrace/breakpointlogic.

Power-on-ResetEmulation

AsoftwarerandomizationprocessthatwritesrandomvaluesindataRAMareastosimulateuninitializedvaluesinRAMuponinitialpowerapplication.

Pragma

Adirectivethathasmeaningtoaspecificcompiler.Oftenapragmaisusedtoconveyimplementation-definedinformationtothe

compiler.MPLABC30usesattributestoconveythisinformation.

PROMATEII

AdeviceprogrammerfromMicrochip.ProgramsallPICmicromicrocontrollersandmostmemoryandKeeloqdevices.CanbeusedwithMPLABIDEorstand-alone.

ProgramCounter

Thelocationthatcontainstheaddressoftheinstructionthatiscurrentlyexecuting.

ProgramMemory

Thememoryareainadevicewhereinstructionsarestored.Also,thememoryintheemulatororsimulatorcontainingthedownloadedtargetapplicationfirmware.

Project

Asetofsourcefilesandinstructionstobuildtheobjectandexecutablecodeforanapplication.

PrototypeSystem

Atermreferringtoauser'stargetapplication,ortargetboard.

PWMSignals

PulseWidthModulationSignals.CertainPICmicroMCUdeviceshaveaPWMperipheral.

Qualifier

AnaddressoranaddressrangeusedbythePassCounterorasaneventbeforeanotheroperationinacomplextrigger.

Radix

Thenumberbase,HEX,ordecimal,usedinspecifyinganaddress.

RAM

RandomAccessMemory(DataMemory).Memoryinwhichinformationcanbeaccessedinanyorder.

RawData

Thebinaryrepresentationofcodeordataassociatedwithasection.

Real-Time

WhenreleasedfromthehaltstateintheemulatororMPLABICDmode,theprocessorrunsinreal-timemodeandbehavesexactlyasthenormalchipwouldbehave.Inreal-timemode,thereal-timetracebufferofMPLABICEisenabledandconstantlycapturesallselectedcycles,andallbreaklogicisenabled.IntheemulatororMPLABICD,theprocessorexecutesinreal-timeuntilavalidbreakpointcausesahalt,oruntiltheuserhaltstheemulator.Inthesimulatorreal-timesimplymeansexecutionofthemicrocontrollerinstructionsasfastastheycanbesimulatedbythehostCPU.

RecursiveCalls

Afunctionthatcallsitself,eitherdirectlyorindirectly.

Recursion

Theconceptthatafunctionormacro,havingbeendefined,cancallitself.Greatcareshouldbetakenwhenwritingrecursivemacros;itiseasytogetcaughtinaninfiniteloopwheretherewillbenoexitfromtherecursion.

Reentrant

Afunctionthatmayhavemultiple,simultaneouslyactiveinstances.

Thismayhappenduetoeitherdirectorindirectrecursionorthroughexecutionduringinterruptprocessing.

Relocatable

Anobjectfilewhosesectionshavenotbeenassignedtoafixedlocationinmemory.

ROM

ReadOnlyMemory(ProgramMemory).Memorythatcannotbemodified.

Run

Thecommandthatreleasestheemulatorfromhalt,allowingittoruntheapplicationcodeandchangeorrespondtoI/Oinrealtime.

RuntimeModel

Describestheuseoftargetarchitectureresources.

Section

Anamedsequenceofcodeordata.

SectionAttribute

Acharacteristicascribedtoasection(e.g.,anaccesssection).

SFR

SeeSpecialFunctionRegisters.

Shell

TheMPASMassemblershellisapromptedinputinterfacetothemacroassembler.TherearetwoMPASMassemblershells:onefortheDOSversionandonefortheWindowsversion.

Simulator

Asoftwareprogramthatmodelstheoperationofdevices.

SingleStep

Thiscommandstepsthoughcode,oneinstructionatatime.Aftereachinstruction,MPLABIDEupdatesregisterwindows,watchvariables,andstatusdisplayssoyoucananalyzeanddebuginstructionexecution.YoucanalsosinglestepCcompilersourcecode,butinsteadofexecutingsingleinstructions,MPLABIDEwillexecuteallassemblylevelinstructionsgeneratedbythelineofthehighlevelCstatement.

Skew

Theinformationassociatedwiththeexecutionofaninstructionappearsontheprocessorbusatdifferenttimes.Forexample,theexecutedOpcodesappearsonthebusasafetchduringtheexecutionofthepreviousinstruction,thesourcedataaddressandvalueandthedestinationdataaddressappearwhentheOpcodesisactuallyexecuted,andthedestinationdatavalueappearswhenthenextinstructionisexecuted.Thetracebuffercapturestheinformationthatisonthebusatoneinstance.Therefore,onetracebufferentrywillcontainexecutioninformationforthreeinstructions.Thenumberofcapturedcyclesfromonepieceofinformationtoanotherforasingleinstructionexecutionisreferredtoastheskew.

Skid

Whenahardwarebreakpointisusedtohalttheprocessor,oneormoreadditionalinstructionsmaybeexecutedbeforetheprocessorhalts.Thenumberofextrainstructionsexecutedaftertheintendedbreakpointisreferredtoastheskid.

SourceCode

Theforminwhichacomputerprogramiswrittenbythe

programmer.Sourcecodeiswritteninsomeformalprogramminglanguagewhichcanbetranslatedintoormachinecodeorexecutedbyaninterpreter.

SourceFile

AnASCIItextfilecontainingsourcecode.

SpecialFunctionRegisters

Theportionofdatamemory(RAM)dedicatedtoregistersthatcontrolI/Oprocessorfunctions,I/Ostatus,timers,orothermodesorperipherals.

Stack,Hardware

LocationsinPICmicromicrocontrollerwherethereturnaddressisstoredwhenafunctioncallismade.

Stack,Software

Memoryusedbyanapplicationforstoringreturnaddresses,functionparameters,andlocalvariables.Thismemoryistypicallymanagedbythecompilerwhendevelopingcodeinahigh-levellanguage.

StaticRAMorSRAM

StaticRandomAccessMemory.ProgrammemoryyoucanRead/Writeonthetargetboardthatdoesnotneedrefreshingfrequently.

StatusBar

TheStatusBarislocatedonthebottomoftheMPLABIDEwindowandindicatessuchcurrentinformationascursorposition,developmentmodeanddevice,andactivetoolbar.

StepInto

ThiscommandisthesameasSingleStep.StepInto(asopposedtoStepOver)followsaCALLinstructionintoasubroutine.

StepOver

StepOverallowsyoutodebugcodewithoutsteppingintosubroutines.WhensteppingoveraCALLinstruction,thenextbreakpointwillbesetattheinstructionaftertheCALL.Ifforsomereasonthesubroutinegetsintoanendlessloopordoesnotreturnproperly,thenextbreakpointwillneverbereached.TheStepOvercommandisthesameasSingleStepexceptforitshandlingofCALLinstructions.

Stimulus

Inputtothesimulator,i.e.,datageneratedtoexercisetheresponseofsimulationtoexternalsignals.Oftenthedataisputintotheformofalistofactionsinatextfile.Stimulusmaybeasynchronous,synchronous(pin),clockedandregister.

Stopwatch

Acounterformeasuringexecutioncycles.

StorageClass

Determinesthelifetimeofanobject.

StorageQualifier

Indicatesspecialpropertiesofanobject(e.g.,volitile).

Symbol

Asymbolisageneralpurposemechanismfordescribingthevariouspieceswhichcompriseaprogram.Thesepiecesinclude

functionnames,variablenames,sectionnames,filenames,struct/enum/uniontagnames,etc.SymbolsinMPLABIDErefermainlytovariablenames,functionnamesandassemblylabels.Thevalueofasymbolafterlinkingisitsvalueinmemory.

SystemWindowControl

Thesystemwindowcontrolislocatedintheupperleftcornerofwindowsandsomedialogs.Clickingonthiscontrolusuallypopsupamenuthathastheitems"Minimize,""Maximize,"and"Close."

Target

Referstouserhardware.

TargetApplication

Softwareresidingonthetargetboard.

TargetBoard

Thecircuitryandprogrammabledevicethatmakesupthetargetapplication.

TargetProcessor

Themicrocontrollerdeviceonthetargetapplicationboard.

Template

Linesoftextthatyoubuildforinsertingintoyourfilesatalatertime.TheMPLABEditorstorestemplatesintemplatefiles.

ToolBar

AroworcolumnoficonsthatyoucanclickontoexecuteMPLABIDEfunctions.

Trace

Anemulatororsimulatorfunctionthatlogsprogramexecution.TheemulatorlogsprogramexecutionintoitstracebufferwhichisuploadedtoMPLABIDE'stracewindow.

TraceMemory

Tracememorycontainedwithintheemulator.Tracememoryissometimescalledthetracebuffer.

TriggerOutput

Triggeroutputreferstoanemulatoroutputsignalthatcanbegeneratedatanyaddressoraddressrange,andisindependentofthetraceandbreakpointsettings.Anynumberoftriggeroutputpointscanbeset.

UninitializedData

Datawhichisdefinedwithoutaninitialvalue.InC,

intmyVar;

definesavariablewhichwillresideinanuninitializeddatasection.

Upload

TheUploadfunctiontransfersdatafromatool,suchasanemulatororprogrammer,tothehostPCorfromthetargetboardtotheemulator.

Vector

Thememorylocationsfromwhichanapplicationstartsexecutionwhenaspecificeventoccurs,suchasaresetorinterrupt.

Warning

Analertthatisprovidedtowarnyouofasituationthatwouldcausephysicaldamagetoadevice,softwarefile,orequipment.



WatchVariable

Avariablethatyoumaymonitorduringadebuggingsessioninawatchwindow.

WatchWindow

Watchwindowscontainalistofwatchvariablesthatareupdatedateachbreakpoint.

WatchdogTimer

AtimeronaPICmicromicrocontrollerthatresetstheprocessorafteraselectablelengthoftime.TheWDTisenabledordisabledandsetupusingconfigurationbits.

WDT

SeeWatchdogTimer.





ListofControlDirectives

Directive Description Syntax

CONSTANT DeclareSymbolConstant constant<label>[=<expr>,...,<label>[=<expr>]]

#DEFINE DefineaTextSubstitutionLabel

#define<name>[[(<arg>,...,<arg>)]<value>]

END EndProgramBlock end

EQU DefineanAssemblyConstant <label>equ<expr>

#INCLUDE IncludeAdditionalSourceFile

include<<include_file>>include"<include_file>"

ORG SetProgramOrigin <label>org<expr>PROCESSOR SetProcessorType processor<processsor_type>RADIX SpecifyDefaultRadix radix<default_radix>

SET DefineanAssemblerVariable <label>set<expr>

#UNDEFINE DeleteaSubstitutionLabel #undefine<label>

VARIABLE DeclareSymbolVariable variable<label>[=<expr>,...,<label>[=<expr>]]




Directiveshighlightedinthisexampleare:

processor

radix#includeequorgend

ProgramFunctionalDescription

ThisprogramcontinuallyalternatestheoutputonthePortBpinsfrom1'sto0's.Twodelayroutinesusinginterruptsprovidethetimingforthealternatingoutput.IfLEDswereattachedtoPortB,theywouldflash(1=on,0=off).

ThetypeofPICmicroMCUissetusingprocessor,andtheradixissettohexadecimalusingradix.Thestandardheaderfilefortheprocessorselectedisincludedusing#include.Registersareassignedusingtheequdirective.Sectionsofcodeareblockedoutusingtheorgstatement.Finally,theprogramisfinishedwithanend.

CommentedCodeListing

;**************************************;*MPASMAssemblerControlDirectives*;*ExampleProgram1*;*AlternateoutputonPortBbetween*

;*1'sand0's*;**************************************processor16f877;Settheprocessorradixhex;Settheradix#include<p16f877.inc>;IncludeheaderfileDTEMPequ0x20;SettempregisterDFLAGequ0x21;SetflagregisterDFL0equ0x00;Setflagbitorg0x00;ResetVectorgotoStartorg0x04;InterruptVectorgotoServIntorg0x06;StartProgramStartclrfPORTB;ClearPortBbsfSTATUS,RP0;SelectBank1clrfTRISB;SetPortBasoutputbcfSTATUS,RP0;SelectBank0bsfINTCON,GIE;EnableGlobalInt'sbsfINTCON,T0IE;EnableTimer0IntLoopmovlw0xFFmovwfPORTB;SetPortBcallDelay1;WaitclrfPORTB;ClearPortBbsfPCLATH,3;SelectPage3bsfPCLATH,4callDelay2;WaitbcfPCLATH,3;SelectPage0bcfPCLATH,4gotoLoop;RepeatServInt;InterruptSericeRoutinebsfSTATUS,RP0;SelectBank1bsfOPTION_REG,T0CS;StopTimer0bcfSTATUS,RP0;SelectBank0bcfINTCON,T0IF;ClearoverflowflagbcfDFLAG,DFL0;Clearflagbit

retfie;***************************************;*Delay1Routine-Timer0delayloop*;***************************************Delay1movlw0xF0;SetTimer0valuemovwfTMR0;0x00-longestdelay;0xFF-shortestdelayclrfDFLAGbsfDFLAG,DFL0;SetflagbitbsfSTATUS,RP0;SelectBank1bcfOPTION_REG,T0CS;StartTimer0bcfSTATUS,RP0;SelectBank0TLoopbtfscDFLAG,DFL0;WaitforoverflowgotoTLoop;Timer00xFF->0x00return;******************************************;*Delay2Routine-Decrementdelayloop*;******************************************org0x1900;Page3Delay2movlw0xFF;SetDTEMPvaluemovwfDTEMP;0x00-shortestdelay;0xFF-longestdelayDLoopdecfszDTEMP,FgotoDLoop;EndloopwhenDTEMP=0returnend

AdditionalComments

HeaderFiles

Aheaderfileisincludedintheprogramflowwiththe#include

directive.

#include<p16f877.inc>;Includeheaderfile

Anglebracketsareusedtoenclosethenameofthefiletobeincluded,althoughquotesmayalsobeused.Youmayspecifythecompletepathtotheincludedfile,orlettheassemblersearchforit.Formoreonsearchorder,seethediscussionofthe#includedirective().

Aheaderfileisextremelyusefulforspecifyingoften-usedconstants,suchasregisterandpinnames.Thisinformationcanbetypedinonce,andthenthefilecanbeincludedinanycodeusingtheprocessorwiththoseregistersandpins.

RegisterandBitAssignments

Youcanspecifyyourownregistersandbitsbyusingtheequdirective,asisdoneinthefollowinglines.

DTEMPequ0x20;SettempregisterDFLAGequ0x21;SetflagregisterDFL0equ0x00;Setflagbit

DTEMPandDFLAGareassignedtothevalues0x20and0x21respectively.Theywillbeusedindelayloopsintheprogramtostandforthegeneralpurposeregisters(GPRs)0x20and0x21.DFL0isassignedthevalue0x00andwillbeusedasthenameforpin0intheDFLAGregister.

FIGURE:PIC16F877REGISTERFILEMAP

UsingORG

Theorgdirectiveisusedtospecifytheprogramoriginforspecificsectionsofcode.Ifnoorgisused,codegenerationbeginsataddresszero.ForExample1,orgisusedtospecifycodeat0x00(resetaddress),0x04(interruptaddress),0x06(programstartaddress)and0x1900(Delay2address).

FIGURE:PIC16F877PROGRAMMEMORYMAP



Mostoftheprogramiscontainedonpage0.However,thecodefordelayroutineDelay2hasbeenplacedonpage3.Whencallingthisroutine,youmustremembertousethepagingbitsinthePCLATHtoselectpage3,andthenusethemtoswitchbacktopage0onthereturn.

bsfPCLATH,3;SelectPage3bsfPCLATH,4callDelay2;WaitbcfPCLATH,3;SelectPage0bcfPCLATH,4





#define

#undefineequconstantvariableset


Thisprogramperformsseveralcalculationsusingdefindedconstantsandvariables.Asincontroldirectives-example1,processorisusedtospecifytheprocessortype,radixisusedtospecifytheradixused,and#includeisusedtoincludeaheaderfile.Seeexample1formoreonthesedirectives.


;**************************************;*MPASMAssemblerControlDirectives*;*ExampleProgram2*;*Performcalculations*;**************************************processor16f877;Settheprocessorradixhex;Settheradix#include<p16f877.inc>;Includeheaderfile#defineTdistance150;Definethesymbol;Tdistance1

#defineTdistance225;Definethesymbol;Tdistance2#undefineTdistance2;RemoveTdistance2from;thesymboltabledistance_regequ0x20;Setupdistance_reg;atGPR0x20org0x00;ResetVectorgotoStartorg0x06;StartProgramStartmovlwTdistance1;MovevalueofTdistance1movwfdistance_reg;intodistance_regconstantdistance1=10;Declaredistance1;aconstantsymbolvariabledistance2;Declaredistance2;avariablesymboldistance3set10;Defineavaluefor;thesymboldistance3

Setsymboldistance3to10.

distance2=15;Givedistance2an;initialvaluedistance2=distance1+distance2;Adddistance1;todistance2distance3set15;Changevalueofdistance3distance2=distance2+distance3;Adddistance3;todistance2movlwdistance2;Movevalueofdistance2movwfdistance_reg;intodistance_regend

AdditionalComments

UsingWatchWindows

Oncetheprogrambegins,thevalueofTdistance1isplaced



intodistance_reg.Thiscanbeobservedinawatchwindow,wherethevalueofdistance_regwillbecome50.ThesymbolTdistance1willnotbefoundinthewatchwindowsymbollist,assymbolsdefinedusingthe#definedirectivearenotavailableforviewinginMPLABIDE.

Thefinallinesoftheexampleprogramwritethefinalvalueofdistance2todistance_reg.Ifyouhadawatchwindowopentoseedistance_regloadedwiththevalueof50,youwillseeitchangeto3A.Rememberthattheradixishexadecimal,sohexadditionwasusedtodeterminethedistance2value.

Lookinginthewatchwindowsymbollist,youwillfindthesymbolsdistance1,distance2anddistance3.However,theywillhavenovalues.ThesesymbolvaluesarenotactuallystoredonthePICmicrodevice,butimplementedonlyintheassembler.



ORGPIC16CXXXExample

DirectiveshighlightedinthisexampleforPIC16CXXXdevicesare:

org


Thisexampleshowstheusageoftheorgdirective.Codegenerationbeginsatanaddressspcifiedbyorg<address>.Theoriginofadatatablealsocanbespecifiedbythisdirective.AdatatablemaybeplacedeitherinaprogrammemoryregionorinanEEdatamemoryregion,asincaseofPICmicrodevicewithEEdataFLASH.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.org0000;Thefollowingcodewillbe;placedinresetaddress0.gotoMain;Jumptoanaddresswhoselabel;is'Main'.org0004;Thefollowingcodewillbe;placedininterruptaddress4.gotoint_routine;Jumptoanaddresswhoselabel;is'int_routine'.org0010;Thefollowingcodesectionwill;placedstartingfromaddress10H.Main;;Writeyourmainprogramhere.;;



gotoMain;Loopbackto'Main'.org0100;Thefollowingcodesectionwill;beplacedstartingfromaddress;100H.int_routine;;;Writeyourinterruptservice;;routinehere.retfie;Returnfrominterrupt.org1000;Youcancreateadataor;charactertablestartingfrom;anyaddressinprogrammemory.;Inthiscasetheaddressis;1000h.ch_tbl1da"PICwithFLASH";6programmemorylocations;(startingfrom1000h)will;befilledwithsix14-bit;packednumbers,each;representingtwo7-bitASCII;characters.org2100;Theabsolueaddress2100his;mappedtothe0000locationof;EEdatamemoryinPIC16Fxxx.;Youcancreateadataor;charactertablestartingfrom;anyaddressinEEdatamemory.ch_tbl2de"PICwithFLASH";12EEdatamemorylocations;(startingfrom0)willbe;filledwith12ASCII;characters.end



ORGPIC18CXXXExample


org


Thisexampleshowstheusageoftheorgdirective.Codegenerationbeginsatanaddressspcifiedbyorg<address>.Theoriginofadatatablealsocanbespecifiedbythisdirective.AdatatablemaybeplacedeitherinaprogrammemoryregionorinanEEdatamemoryregion,asincaseofPICmicrodevicewithEEdataFLASH.


listp=18c452;Selectthedevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.org0000;Thefollowingcodewillbe;programmedinresetaddress0.gotoMain;Jumptoanaddresswhoselabelis;'Main'.org0008;Thefollowingcodewillbe;programmedinhighpriority;interruptaddress8.gotoint_hi;Jumptoanaddresswhoselabelis;'int_hi'.org0018;Thefollowingcodewillbe;programmedinlowpriority;interruptaddress18h.gotoint_lo;Jumptoanaddresswhoselabelis;'int_lo'.



org0010;Thefollowingcodesectionwill;beprogrammedstartingfrom;address10H.Main;;Writeyourmainprogramhere.;;gotoMain;Loopbackto'Main'org0100;Thefollowingcodesectionwill;beprogrammedstartingfrom;address100H.int_hi;;;Writeyourhighpriority;;interruptserviceroutinehere.retfie;Returnfrominterrupt.org0200;Thefollowingcodesectionwill;beprogrammedstartingfrom;address200H.int_lo;;;Writeyourlowpriority;;interruptserviceroutinehere.retfie;Returnfrominterrupt.org1000;Youcancreateadataor;charactertablestartingfromany;addressinprogrammemory.In;thiscasetheaddressis1000h.ch_tbl1db"PICwithFLASH"end



RADIXExample


listr=

radix


Thisexampleshowstheusageoftheradixdirectivefordatapresentation.Ifnotdeclared,thenthedefaultradixisinhex(adecimal).


listp=16f877,r=dec;Selectthedeviceandset;radixasdecimal.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.movlw50H;50isinhexmovlw0x50;Anotherwayofdeclaring50hexmovlw50O;50isinoctalmovlw50;50isnotdeclaredashexor;octalordecimal.Sobydefault;itisindecimalasdefaultradix;isdeclaredasdecimal.radixoct;Use`radix'todeclaredefault;radixasoctal.movlw50H;50isinhex.movlw0x50;Anotherwayofdeclaring50hex.movlw.50;50isindecimal.movlw50;50isnotdeclaredashexor;octalordecimal.Sobydefault



;itisinoctalasdefaultradix;isdeclaredasoctal.radixhex;Nowdefaultradixisinhex.movlw.50;50isdeclaredindecimal.movlw50O;50isdeclaredinoctalmovlw50;50isnotdeclaredashexor;octalordecimal.Sobydefault;itisinhexasdefaultradix;isdeclaredashex.end



SET/EQUExample


set

equ


Thisexampleshowsthetheusageofthesetdirective,usedforcreatingsymbolswhichmaybeusedinMPASMassemblerexpressionsonly.Thesymbolscreatedwiththisdirectivedonotoccupyanyphysicalmemorylocationofmicrocontroller.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.perimeterset0;Thelabel'perimeter'is;assignedvalue0.areaset0;Thelabel'area'isassigned;value0.lngthequ50H;Thelabel'lngth'isassigned;thevalue50H.wdthequ25H;Thelabel'wdth'isassigned;thevalue25H.perimeterset2*(lngth+wdth);Both'perimeter'andareasetlngth*wdth;'area'valuesare;reassigned.end





UNDEFINE/DEFINEExample


#undefine

#define


Thisexampleshowsthetheusageof#UNDEFINEdirective.Asymbolnamepreviouslydefinedwiththe#DEFINEdirective,isremovedfromthesymboltableif#UNDEFINEdirectiveisused.Thesamesymbolmayberedefinedagain.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.areaset0;Thelabel'area'isassigned;thevalue0.#definelngth50H;Label'lngth'isassigned;thevalue50H.#definewdth25H;Label'wdth'isassigned;thevalue25Hareasetlngth*wdth;Reassignmentoflabel'area'.;So'area'willbereassigneda;valueequalto50H*25H.#undefinelngth;Undefinelabel'lngth'.#undefinewdth;Undefinelabel'wdth'#definelngth0;Definelabel'lngth'to'0'.end





VARIABLE/CONSTANTExample


variable

constant


Thisexampleshowsthetheusageofthevariabledirective,usedforcreatingsymbolswhichmaybeusedinMPASMassemblerexpressionsonly.Thesymbolscreatedwiththisdirectivedonotoccupyanyphysicalmemorylocationofmicrocontroller.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.variableperimeter=0;Thesymbol'perimeter'is;initializedto0variablearea;Ifasymbolisdeclaredas;variable,theninitialization;isoptional,i.e.itmayormay;notbeinitialized.constantlngth=50H;Thesymbol'lngth'is;initializedto50H.constantwdth=25H;Thesymbol'wdth'is;initializedto25H.;Aconstantsymbolalwaysneeds;tobeinitialized.perimeter=2*(lngth+wdth);ThevalueofaCONSTANTcannot



;bereassignedafterhavingbeen;initializedonce.So'lngth'and;'wdth'cannotbereassigned.But;'perimeter'hasbeendeclared;asvariable,andsocanbe;reassigned.area=lngth*wdthend





ListofConditionalAssemblyDirectives

Directive Description SyntaxELSE BeginAlternativeAssemblyBlocktoIF elseENDIF EndConditionalAssemblyBlock endifENDW EndaWhileLoop endwIF BeginConditionallyAssembledCodeBlock if<expr>IFDEF ExecuteIfSymbolisDefined ifdef<label>IFNDEF ExecuteIfSymbolisNotDefined ifndef<label>WHILE PerformLoopWhileConditionisTrue while<expr>



IF/ELSE/ENDIFExample


if

elseendif


ThisprogramdemonstratestheutilityofIF,ELSEandENDIFassemblydirectives.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.variableconfig;variableusedtodefine;requiredconfigurationof;PORTA&PORTBconfigsetD'1'RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled



;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startifconfig==H'0';Ifconfig==H'0'istrue,clrw;assemblethemnemonicsuptomovwfTRISA;thedirective'else'.movlwH'ff'movwfTRISBelseclrw;Ifconfig==H'0'isfalse,movwfTRISB;assemblethemnemonicsuptomovlwH'ff';thedirective'endif'.movwfTRISAendifgoto$service_intretfieend



IFDEFExample


#define

ifdefelseendif


Thisprogramusesthecontroldirective#define,alongwiththeifdef,elseandendifdirectivestoseletivelyassemblecodeforusewitheitheranemulatororanacutalpart.Thelistdirectivestitleandlistp=areusedtosetthetitleandprocessoranddisplaythisinformationinthelistfile.Thecontroldirective#includeisusedtoincludethestandardheaderfilefortheselecteddevice.


title"PICmicrowithFlashEEdatamemoryInterface"listp=12ce518#include<p12ce518.inc>;#defineEMULATED...;EmulationRequires:;MPLAB-ICE;PCM16XA0processormodule;DVA12XP80DeviceAdapter



;DefineEMULATORatthetopofthisfile;(#defineEMULATOR);ThiswillsettheI2C_PORT,SDAandSCLlines;tocommunicateoverPortA,pins0and1.It;alsoassemblesinthenecessaryTRIS;instructionstoallowreadingfromtheSDAline.;;Toconvertthecodefortheactualpart,simplycomment;outthe#defineEMULATORlineandreassemble....#ifdefEMULATEDI2C_PORTEQU5;PortAcontrolregister,;usedforI2CSCLEQU01H;EEPROMClock,SCL(I/Obit7)SDAEQU00H;EEPROMData,SDA(I/Obit6)#elseI2C_PORTEQUGPIO;PortBcontrolregister,;usedforI2CSCLEQU07H;EEPROMClock,SCL(I/Obit7)SDAEQU06H;EEPROMData,SDA(I/Obit6)#endif...START_BITBCFI2C_PORT,SDA;Startbit,SDAandSCL;presetto"1"



WHILE/ENDWExample


while

endw


Thisexampleshowstheusefulnessofdirectivewhiletoperformaloopwhileacertainconditionistrue.Thisdirectiveisusedwiththeendwdirective.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.variablei;Definethesymbol'i'asa;variable.reg_hiequ20;Assignvalue20Htolabel;reg_hi.reg_loequ21;Assignvalue21Htolabel;reg_lo.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresswhoselabel;is'start'.shift_rightmacroby_n;Beginningofamacro,which;shiftsregisterdatantimes.;Codelengthgeneratedafter;assembly,variesdependingupon;thevalueofparameter'by_n'.



i=0;Initializevariablei.whilei<by_n;Following3linesofassembly;codearerepeatedaslongas;i<by_n.bcfSTATUS,C;Clearcarrybit.rrfreg_hi;reg_hiandreg_locontainsrrfreg_lo;16-bitdatawhichisrotated;rightthroughcarry.i+=1;Incrementloopcounteri.endw;Endwhileloop.Theloopwill;breakhereafteri=by_n.endm;Endof'shift_right'macro.org0010;Mymainprogramstartsat10H.start;Thelabel'start'isequalto;10H.shift_right3;Shiftright3timesthe16-bit;datainreg_hiandreg_lo.This;isanexample.Avalue8will;shiftdata8times.goto$end





ListofDataDirectives


__BADRAM SpecifyinvalidRAMlocations __badram<expr>

CBLOCK DefineaBlockofConstants cblock[<expr>]

CODE_PACK NoPaddingatEndofOddByte code_pack

__CONFIG Setconfigurationfuses __config<expr>OR__config<addr>,<expr>

DA StoreStringsinProgramMemory

[<label>]da<expr>[,<expr2>,...,<exprn>]

DATA CreateNumericandTextData

data<expr>,[,<expr>,...,<expr>]data"<text_string>"[,"<text_string>",...]

DB DeclareDataofOneByte db<expr>[,<expr>,...,<expr>]DE DeclareEEPROMData de<expr>[,<expr>,...,<expr>]DT DefineTable dt<expr>[,<expr>,...,<expr>]

DW DeclareDataofOneWord dw<expr>[,<expr>,...,<expr>]

ENDC EndanAutomaticConstantBlock endc

FILL SpecifyMemoryFillValue fill<expr>,<count>

__IDLOCS SetIDlocations __idlocs<expr>

__MAXRAM SpecifymaximumRAMaddress __maxram<expr>

RES ReserveMemory res<mem_units>



CBLOCK/ENDCExample


cblock

endc


ThisexampleshowstheusageofCBLOCKandENDCdirectivesfordefiningconstantsorvariablersindatamemoryspace.Thesamedirectivescanbeusedforprogrammemoryspacealso.

Theprogramcalculatestheperimeterofarectangle.Lengthandwidthoftherectanglewillbestoredinbuffersaddressedbylength(22H)andwidth(23H).Thecalculatedperimeterwillbestoredinthedouble-precisionbufferaddressedbyperimeter(i.e.20Hand21H).


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.CBLOCK0x20;Startingaddressofprogramor;datamemoryspace.Herethevalue;is20H,whichisindatamemory;space.perimeter:2;Thelabelperimeteris2-byte;wide.Address20Hand21His;assignedtothelabelperimeter.length;Address22Hisassignedtothe;labellength.



width;Address23Hisassignedtothe;labelwidth.ENDC;Thisdirectivemustbesupplied;attheendofCBLOCKlistto;terminatethelist.clrfperimeter;Clearthebufferaddressedby;'perimeter'i.e.address20H.clrfperimeter+1;Clearaddress21H.movflength,w;Movethedatapresentinthe;registeraddressedby'length';to'w'addwfwidth,w;Adddatain'w'withdatainthe;registeraddressedby'width'.movwfperimeter;Move'w'totheregister;addressedby20H.incfszperimeter+1;Incrementregister21Hifcarry;isgenerated.bcfSTATUS,C;ClearcarrybitinSTATUS;register.rlfperimeter+1rlfperimeterincfszperimeter+1;Highbyteofperimeterisin;21Handlowbyteisin20H.goto$end



CONFIGPIC16CXXXExample


__config


Thisprogramdemonstratestheutilityofthe__configdirective.Thisdirectiveisusedtoprogramconfigurationbitsintheconfigurationregisterduringdeviceprogramming.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.__config_LP_OSC;Configurationregisteris;programmedtoselectlow;poweroscillator.Referto;datasheetfordetailsof;configurationregister.RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0.';Theinstruction'gotostart';isplacedincodesectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRT;isplacedatH'4'.;Theinstruction'goto;service_int'isplacedincode;sectionINTRT.gotoservice_int;Jumpstothelocation



;labelled'service_int'.PGMCODE;Thisisthebeginingofthe;codesectionnamedPGM.Itis;arelocatablecodesection;sincenoabsoluteaddressis;givenalongwithdirectivestart;'CODE'.goto$service_intretfieend



CONFIGPIC18CXXXExample


__config


Thisprogramdemonstratestheutilityofthe__configdirective.Thisdirectiveisusedtoprogramconfigurationbitsintheconfigurationregisterduringdeviceprogramming.


listp=18c452;Selectthedevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.;codeprotectdisabled.__CONFIG_CONFIG0,_CP_OFF_0;Oscillatorswitchdisabled,RCoscillatorwithOSC2;asI/Opin.__CONFIG_CONFIG1,_OSCS_OFF_1&_RCIO_OSC_1;Brown-OutResetenabled,BORVoltageis2.5v__CONFIG_CONFIG2,_BOR_ON_2&_BORV_25_2;WatchDogTimerenable,WatchDogTimerPostScaler;count-1:128__CONFIG_CONFIG3,_WDT_ON_3&_WDTPS_128_3;CCP2pinMuxenabled__CONFIG_CONFIG5,_CCP2MX_ON_5;Stackover/underflowResetenabled__CONFIG_CONFIG6,_STVR_ON_6RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.;Theinstruction'gotostart'



;isplacedincodesectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'8';ThecodesectionnamedINTRT;isplacedatH'4'.;Theinstruction'gotoservice_int';isplacedincodesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesection;sincenoabsoluteaddressis;givenalongwithdirectivestart;'CODE'.goto$service_intretfieend



DAExample


da


Thisexampleshowstheusefulnesofdirectivedainstoringacharacterstringintheprogrammemoryof14-bitarchitecturedevices.Thisdirectivegeneratesapacked14-bitnumberrepresentingtwo7-bitASCIIcharacters.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.start;Writeyourmainprogramhereto;displaythestringgivenin;'Ch_stng'.goto$ORG1000;Storethestringstartingfrom;1000H.Ch_stngda"PICmicro"Sngl_chda"A";7-bitASCIIequivalentsof'A';andaNULLcharaterwillbepacked;ina14-bitnumber.da0xff55;Places3f55inprogrammemory.;Nopacking.



end

AdditionalComments

Determining14-BitNumbers

Forthefollowingstatement:

Ch_stngda"PICmicro"

directivedaproducesfour14-bitnumbers:2849,21ED,34E3and396FrepresentingtheASCIIequivalentofPI,Cm,icandro.

Toseehowthe14-bitnumbersaredetermined,let'slookattheASCIIvaluesofPandI,whichare50h(01010000)and49h(01001001)respectively.Eachispresentedin7-bitas(0)1010000and(0)1001001respectively.Thepacked14-bitnumberis10100001001001,whichisstoredas(00)10100001001001or2849.



DATAPIC16CXXXExample


data


Thisexampleshowstheusefulnesofdirectivedatainstoringoneormorewordsinprogrammemory.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.start;Writeyourmainprogramhereto;displaythestringgivenin;'Ch_stng'.goto$ORG1000;Storethestringstartingfrom;1000H.Ch_stngdata'M','C','U';3programmemorylocations;willbefilledwithASCII;equivalentof'M','C'and;'U'.tb1_dtadata0xffff,0xaa55;Places3fffhand2a55hin;twoconsecutiveprogram;memorylocations.Asprogram;memoryis14-bitwide,



;thelastnibblecanstore;amaximumvalue3.end



DATAPIC18CXXXExample


data


Thisexampleshowstheusefulnesofdirectivedatainstoringoneormorewordsinprogrammemory.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.start;Writeyourmainprogramhereto;displaythestringgivenin;'Ch_stng'.goto$ORG1000;Storethestringstartingfrom;1000H.InPIC18Cxxxdevices,the;firstcharacterisinleast;significantbyte.Ch_stngdata'M','C','U';3programmemorylocations;willbefilledwithASCII;equivalentof'M','C'and;'U'.Ch_stg1data"MCU";2programmemorylocations;willbefilledwithtwo



;words(16-bitnumbers),;eachrepresentingASCI;equivalentoftwo;characters.Thelast;characterwillbetakenas;NULLincaseoddnumberof;charactersarespecified.tb1_dtadata0xffff,0xaa55;Placesffffandaa55in;twoconsecutive;programmemorylocation.end





DBPIC16CXXXExample


db


Thisexampleshowstheusefulnessofdirectivedbinstoringoneormorebyteorcharacterinprogrammemory.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.start;Writeyourmainprogramhere.goto$ORG1000;Storethestringstartingfrom;1000H.Ch_stngdb0,'M',0,'C',0,'U'tb1_dtadb0,0xff;Places00ffinprogrammemory;location.end



DBPIC18CXXXExample


db


Thisexampleshowstheusefulnesofdirectivedbinstoringoneormorebyteorcharacterinprogrammemory.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.ORG0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.start;Writeyourmainprogramhereto;displaythestringgivenin;'Ch_stng'.goto$ORG1000;Storethestringstartingfrom;1000H.InPIC18Cxxxdevices,the;firstcharacterisinleast;significantbyte.Ch_stngdb'M','C','U'tb1_dtadb0,0xff;Placesff00inprogrammemory;location.end







DEPIC16CXXXExample


de


Thisexampleshowstheusageofthededirective.ThisdirectiveisdesignedmainlyforinitializingdataintheEEdatamemoryregionofPICmicrodeviceswithEEdataFLASH.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.org2100;Theabsolueaddress2100his;mappedtothe0000locationof;EEdatamemory.ch_tbl2de"PICmicro";6EEdatamemorylocations;(startingfrom0)willbefilled;with6ASCIIcharacters.end





DEPIC18CXXXExample


de


Thisexampleshowstheusageofthededirective.ThisdirectiveisdesignedmainlyforinitializingdataintheEEdatamemoryregionofPICmicrodeviceswithEEdataFLASH.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.orgF0;TheabsolueaddressF0his;mappedtothe0000locationof;EEdatamemory.ch_tbl2de"PICmicro";6EEdatamemorylocations;(startingfrom0)willbefilled;with6ASCIIcharacters.end



FILLPIC16CXXXExample


fill


Thefilldirectiveisusedtoprogramsuccessiveprogrammemorylocationswithaconstantoranassemblyinstruction.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.org0000;Thefollowingcodewillbe;programmedinresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.FILL0,INTRPT-$;Fillwith0uptoaddress3.INTRPTorg0004gotoISRFILL(gotostart),start-$;Filluptoaddress0Fhwith;instruction<gotostart>.ORG0010start;Writeyourmainprogramhere.FILL(nop),5;Fill5locationswithNOPs.goto$ISR;RETFIEEND





FILLPIC18CXXXExample


fill


Thefilldirectiveisusedtoprogramsuccessiveprogrammemorylocationswithaconstantoranassemblyinstruction.ForPIC18CXXXdevices,onlyanevennumberisallowedtobespecifiedasacountoflocationstobefilled.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.org0000;Followingcodewillbeprogrammed;inresetaddress0.gotostart;Jumptoanaddresslabelled;'start'.FILL0,HI_INT-$;Fills0in2programmemory;locations:0004and0006.HI_INTorg0008gotoINTR_HFILL(gotostart),6;Fills6locations(eachlocation;is2byteswide)with3numbers;of2wordwideinstructions;<gotostart>LO_INTorg0018gotoINTR_LFILL10a9,start-$;Fillsaddress1Chand1Ehwith;10a9h



ORG0020start;Writeyourmainprogramhere;FILL(nop),4;Fills2locations(4bytes)with;NOPgoto$INTR_H;RETFIEINTR_L;RETFIEEND



IDLOCPIC16CXXXExample


__idloc


Thisprogramdemonstratestheutilityofthe__idlocsdirective.ThisdirectiveisusedtoprogramdeviceIDbitsintheIDLOCregisterduringdeviceprogramming.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.__idlocsH'1234';SetsdeviceIDto1234.RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.;Theinstruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalong



start;withdirective'CODE'.goto$service_intretfieend



IDLOCPIC18CXXXExample


__idloc


Thisprogramdemonstratestheutilityofthe__idlocsdirective.ThisdirectiveisusedtoprogramdeviceIDbitsintheIDLOCregisterduringdeviceprogramming.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.__IDLOCS_IDLOC0,H'1';IDLOCregister0willbe;programmedto1.__IDLOCS_IDLOC1,H'2';IDLOCregister1willbe;programmedto2.__IDLOCS_IDLOC2,H'3';IDLOCregister2willbe;programmedto3.__IDLOCS_IDLOC3,H'4';IDLOCregister3willbe;programmedto4.__IDLOCS_IDLOC4,H'5';IDLOCregister4willbe;programmedto5.__IDLOCS_IDLOC5,H'6';IDLOCregister5willbe;programmedto6.__IDLOCS_IDLOC6,H'7';IDLOCregister6willbe;programmedto7.__IDLOCS_IDLOC7,H'8';IDLOCregister7willbe;programmedto8.RSTCODEH'0';ThecodesectionnamedRST



;isplacedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'8';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalongstart;withdirective'CODE'.goto$service_intretfieend



RESExample


res


Thisexampleshowstheadvantageofresdirectiveindevelopingrelocatablecode.Theprogramcalculatestheperimeterofarectangle.Lengthandwidthoftherectanglewillbestoredinbuffersaddressedbylengthandwidth.Thecalculatedperimeterwillbestoredinthedouble-precisionbufferaddressedbyperimeter.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.UDATA;Thisdirectiveallowsthe;followingdatatobeplacedonly;inthedataarea.perimeterres2;Twolocationsofmemoryare;reservedforthelabel;'perimeter'.Addressesofthe;memorylocationswillbe;allocatedbyMPLINK.lengthres1;Onelocationofmemoryis;reservedforthelabel'length'.;Addressofthememorylocation;willbeallocatedbyMPLINK.widthres1;Onelocationofmemoryis;reservedforthelabel'width'.



;Addressofthememorylocation;willbeallocatedbyMPLINK.StartCODE0000;Followingcodewillbeplacedin;address0.gotoPER_CAL;JumptolabelPER_CALCODE;CODEdirectiveheredictatesthat;thefollowinglinesofcodewill;beplacedinprogrammemory,but;thestartingaddresswillbe;decidedbyMPLINK.PER_CALclrfperimeter;Clearthebuffersaddressedbyclrfperimeter+1;'perimeter'.movflength,w;Movethedatapresentinthe;registeraddressedby'length';to'w'.addwfwidth,w;Adddatain'w'withdatainthe;registeraddressedby'width'movwfperimeter;Move'w'totheregister;addressedby'perimeter'.incfszperimeter+1;Increment'perimeter+1'ifcarry;isgenerated.bcfSTATUS,C;ClearcarrybitinSTATUS;register.rlfperimeter+1rlfperimeterincfszperimeter+1goto$end





ListofListingDirectives

Directive Description SyntaxERROR IssueanErrorMessage error"<text_string>"ERRORLEVEL SetMessgeLevel errorlevel0|1|2|<+-><msg>LIST ListingOptions list[<option>[,...,<option>]]MESSG CreateUserDefinedMessage messg"<message_text>"NOLIST TurnoffListingOutput nolistPAGE InsertListingPageEject pageSPACE InsertBlankListingLines space[<expr>]SUBTITLE SpecifyProgramSubtitle subtitl"<sub_text>"TITLE SpecifyProgramTitle title"<title_text>"



ERRORExample


error


Thisprogramdemonstratestheutilityoftheerrorassemblerdirective,whichsetsanerrormessagetobeprintedinthelistingfileanderrorfile.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.variablebaudrate;variableusedtodefine;requiredbaudratebaudratesetD'5600';Entertherequiredvalueof;baudratehere.if(baudrate!=D'1200')&&(baudrate!=D'2400')&&(baudrate!=D'4800')&&(baudrate!=D'9600')&&(baudrate!=D'19200')error"Selectedbaudrateisnotsupported"endifRSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction



;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startgoto$service_intretfieend



ERRORLEVELExample


errorlevel


Thisprogramdemonstratestheutilityoftheerrorlevelassemblerdirective,whichsetsthetypeofmessagesthatareprintedinthelistingfileanderrorfile.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.errorlevel0;Display/printmessages,;warningsanderrors.messg"CAUTION:Thisprogramhaserrors"errorlevel1;Display/printwarnings;anderrors.messg"CAUTION:Thisprogramhaserrors"group1udata0x20group1_var1res1;Labelofthisdirectiveisnot;atcolumn1.Thiswillgenerate;awarningno.207.errorlevel-207;Thisdisableswarningwhose;msgnumis207.group1_var2res1;labelofthisdirectiveisalso;notatcolumn1,butnowarning;isdisplayed/printed.errorlevel+207;Thisenableswarningwhose;msgnumis207



group2udataerrorlevel2;Display/printerrorsgroup2_var1res1;labelofthisdirectiveisnot;atcolumn1.Thiswillgenerate;awarningno.207.errorlevel1;Display/printwarnings;anderrors.group2_var2res1;labelofthisdirectiveisnot;atcolumn1.Thiswillgenerate;awarningno.207.RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRTgotoservice_int;Label'service_int'isnot;defined.Hencethisgenerates;error[113].PGMCODE;Thisisthebeginingofthecode;sectionnamed'PGM'.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalong;withdirective'CODE'startmovwfgroup1_var1goto$end



MESSGExample


messg


Thisprogramdemonstratestheutilityofthemessgassemblerdirective,whichsetsamessagetobeprintedinthelistingfileanderrorfile.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.variablebaudrate;variableusedtodefine;requiredbaudratebaudratesetD'5600';Entertherequiredvalueof;baudratehere.if(baudrate!=D'1200')&&(baudrate!=D'2400')&&(baudrate!=D'4800')&&(baudrate!=D'9600')&&(baudrate!=D'19200')error"Selectedbaudrateisnotsupported"messg"onlybaudrates1200,2400,4800,9600&19200Hz"&&"aresupported"endifRSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.



INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startgoto$service_intretfieend





ListofMacroDirectives

Directive Description SyntaxENDM EndaMacroDefinition endmEXITM ExitfromaMacro exitmEXPAND ExpandMacroListing expandLOCAL DeclareLocalMacroVariable local<label>[,<label>]MACRO DeclareMacroDefinition <label>macro[<arg>,...,<arg>]NOEXPAND TurnoffMacroExpansion noexpand



EXITMExample


exitm


Thisprogramdemonstratestheutilityoftheexitmassemblerdirective,whichcausesanimmediateexitfromamacro.Itisusedintheexampletoexitfromthemacrowhencertainconditionsaremet.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.resultequ20;Assignvalue20Htolabel;result.ORG0000;Thefollowingcodewillbeplaced;inresetaddress0.gotostart;Jumptoanaddresswhoselabelis;'start'.addMACROnum1,num2;'add'isamacro.Thevaluesof;'num1'and'num2'mustbepassed;tothismacro.ifnum1>0xff;Ifnum1>255decimal,extim;forceimmediatereturnfrom;macroduringassembly.elseifnum2>0xff;Ifnum2>255decimal,extim;forceimmediatereturnfrom;macroduringassembly.



elsemovlwnum1;LoadWregisterwithaliteral;valueassignedtothelabel;'num1'.movwfresult;LoadWregistertoanaddress;locationassignedtothelabel;'result'.movlwnum2;LoadWregisterwithaliteral;valueassignedtothelabel;'num2'.addwfresult;AddWregisterwiththememory;locationaddressedby'result';andloadtheresultbackto;'result'.endifendifendm;Endof'add'MACROorg0010;Mymainprogramstartsat10H.start;Thelabel'start'isassignedan;address10H.add.100,.256;Call'add'MACROwithdecimal;numbers100and256assignedto;'num1'and'num2'labels,;respactively.EXTIMdirectivein;macrowillforcereturn.end



LOCALExample


local


Thiscodedemonstratestheutilityoflocaldirective,whichdeclaresthatthespecifieddataelementsaretobeconsideredinlocalcontexttothemacro.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.increqu2;Assemblervariableincrisset;equalto2.add_incrmacro;Declarationofmacro'add_incr'.localincr;Localassemblervariable'incr'.incrset3;Local'incr'issetto3,in;contrastto'incr'value;of2inmaincode.clrw;wregisterissettozeroaddlwincr;wregisterisaddedtoincrand;resultplacedbackendm;inwregister.RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.



INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamed'PGM'.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalong;withdirective'CODE'startclrw;Wregistersettozero.addlwincr;Wregisterisaddedwiththe;valueofincrwhichisnowequal;to2.add_incr;Wregisterisaddedwiththe;valueofincrwhichisnowequal;to3(valuesetlocallyinthe;macroadd_incr).clrw;Wregisterissettozeroagain.addlwincr;incrisaddedtoWregisterand;resultplacedinWregister.;incrvalueisagain2,not;affectedbythevaluesetinthe;macro.goto$service_intretfieend



MACRO/ENDMExample


macro

endm


Thiscodedemonstratestheutilityofmacrodirective,whichisusedtodefineamacro.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.resultequ20;Assignvalue20Htolabel;result.ORG0000;Thefollowingcodewillbeplaced;inresetaddress0.gotostart;Jumptoanaddresswhoselabelis;'start'.addMACROnum1,num2;'add'isamacro.Thevaluesof;'num1'and'num2'mustbepassed;tothismacro.movlwnum1;LoadWregisterwithaliteral;valueassignedtothelabel;'num1'.movwfresult;LoadWregistertoanaddress;locationassignedtothelabel;'result'.movlwnum2;LoadWregisterwithaliteral



;valueassignedtothelabel;'num2'.addwfresult;AddWregisterwiththememory;locationaddressedby'result';andloadtheresultbackto;'result'.endm;endof'add'MACROorg0010;Mainprogramstartsat10H.start;Thelabel'start'isassignedan;address10H.add.100,.90;Call'add'MACROwithdecimal;numbers100and90assignedto;'num1'and'num2'labels,;respactively.100and90willbe;addedandtheresultwillbein;'result'.end





ListofObjectFileDirectives


BANKISEL GenerateRAMbankselectingcodeforindirectaddressing bankisel<label>

BANKSEL GenerateRAMbankselectingcode banksel<label>CODE Beginsexecutablecodesection [<name>]code[<address>]

EXTERN Declaresanexternallabel extern<label>[,<label>]

GLOBAL Exportsadefinedlabel extern<label>[.<label>]

IDATA Beginsinitializeddatasection [<name>]idata[<address>]

PAGESEL GenerateROMpageselectingcode pagesel<label>

UDATA Beginsuninitializeddatasection [<name>]udata[<address>]

UDATA_ACS Beginsaccessuninitializeddatasection [<name>]udata_acs[<address>]

UDATA_OVR Beginsoverlayeduninitializeddatasection [<name>]udata_ovr[<address>]

UDATA_SHR Beginsshareduninitializeddatasection [<name>]udata_shr[<address>]



BANKISELExample


bankisel


Thisprogramdemonstratestheutilityofthebankiseldirective.Thisdirectivegeneratestheappropriatecodetoset/cleartheIRPbitoftheSTATUSregisterforanindirectaccess.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.group1udataH'20';group1datastoredatlocations;startingatH'20'(IRPbit0).group1_var1res1;group1_var1locatedatH'20'.group1_var2res1;group1_var2locatedatH'21'.group2udataH'120';group2datastoredatlocations;startingatH'120'(IRPbit1).group2_var1res1;group2_var1locatedatH'120'.group2_var2res1;group2_var2locatedatH'121'.RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin



;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginningofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startmovlwH'20';ThispartofthecodeaddressesmovwfFSR;variablesgroup1_var1&bankiselgroup1_var1;group1_var2indirectly.clrfINDFincfFSR,FclrfINDFmovwfFSRbankiselgroup2_var1clrfINDFincfFSR,FclrfINDFgoto$service_intretfieend



BANKSELExample


banksel


Thisprogramdemonstratestheutilityofthebankseldirective.Thisdirectivegeneratestheappropriatecodetoset/cleartheRP0andRP1bitsoftheSTATUSregister.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.group1udataH'20';group1datastoredatlocations;startingatH'20'(bank0).group1_var1res1;group1_var1locatedatH'20'.group1_var2res1;group1_var2locatedatH'21'.group2udataH'A0';group2datastoredatlocations;startingatH'A0'(bank1)group2_var1res1group2_var2res1RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin



;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginningofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startbankselgroup1_var1;Thisdirectivegeneratescode;toset/clearbankselectbits;RP0&RP1ofSTATUSregister;dependingupontheaddressof;group1_var1.clrfgroup1_var1clrfgroup1_var2bankselgroup2_var1;Thisdirectivegeneratescode;toset/clearbankselectbits;RP0&RP1ofSTATUSregister;dependingupontheaddressof;group2_var1.clrfgroup2_var1clrfgroup2_var2goto$service_intretfieend



CODEExample


code


Thisprogramdemonstratestheutilityofthecodedirective,whichdeclaresthebeginningofasectionofprogramcode.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.start



clrwgoto$CODE;Thisisarelocatablecodenop;sectionsincenoaddressis;;specifiedwiththeCODE;;directive.;;service_intretfieend



GLOBAL/EXTERNExample


global

extern


Theprogrammain.asm,alongwithsub.asm,demonstratetheutilityoftheGLOBALandEXTERNdirectives,whichmakeitpossibletousesymbolsinmodulesotherthanwheretheyaredefined.


;*******************************************************;main.asm;*******************************************************listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.UDATAdelay_valueres1GLOBALdelay_value;Thevariable'delay_value',;declaredGLOBALinthis;module,isincludedinan;EXTERNdirectiveinthemodule;sub.asm.EXTERNdelay;Thevariable'delay',declared;EXTERNinthismodule,is;declaredGLOBALinthemodule;sub.asm.

RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRSTgotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthe;codesectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgiven;alongwithdirective'CODE'.startmovlwD'10'movwfdelay_valuexorlwH'80'calldelaygotostartservice_intretfieend;*******************************************************;sub.asm;*******************************************************listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.GLOBALdelay;Thevariable'delay'declared;GLOBALinthismoduleis;includedinanEXTERNdirective;inthemodulemain.asm.EXTERNdelay_value;Thevariable'delay_value';declaredEXTERNinthismodule



;isdeclaredGLOBALinthe;modulemain.asm.PGMCODEdelaydecfszdelay_value,1gotodelayreturnend



IDATAExample


idata


Thedirectiveidataisusedwhengeneratinganobjectfile.ItreservesRAMlocationsforvariablesanddirectsthelinkertogeneratealookuptablethatmaybeusedtoinitializethevariablesspecifiedinthissection.TheStartingAddressofthelookuptablecanbeobtainedfromtheMap(.map)file.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.group1IDATA0x20;Initializeddataatlocation;20h.group1_var1res1;group1_var1locatedat0x20,;initializedwith0.group1_var2res1;group1_var2locatedat0x21,;initializedwith0.group2IDATA;Declarationofgroup2data.The;addressesforvariablesunder;thisdatasectionareallocated;automaticallybythelinker.group2_var1db1,2,3,4;4bytesinRAMarereserved.group2_var2dwH'1234';1wordinRAMisreserved.RSTCODE0x0;ThecodesectionnamedRSTis;placedatH'0'.;Followinginstruction'goto



;start'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.PGMCODE;CodesectionnamedPGMis;declared.Itisarelocatable;codesectionsincenoabsolute;addressisspecified.start;;end



PAGESELExample


pagesel


Thisprogramdemonstratestheutilityofthepageseldirective,whichgeneratestheappropriatecodetoset/clearPCLATHbits


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.RSTCODEH'0';ThecodesectionnamedRST;isplacedatH'0'.The;instruction'gotostart'is;placedincodesectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGM0CODEH'500';ThecodesectionnamedPGM0is;placedatH'500'.startPAGESELpage1_pgm;addressbits12&11of;page1_pgmarecopiedtoPCLATH;4&3respectively.



gotopage1_pgmPGM1CODEH'900';ThecodesectionnamedPGM1is;placedatH'900'.Label;page1_pgmislocatedinthispage1_pgm;codesection.goto$service_intretfieend



UDATAExample


udata


Thisprogramdemonstratestheutilityoftheudatadirective,whichdeclaresthebeginningofasectionofuninitializeddata.Thisdirectiveisusedwhengeneratinganobjectfile.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.group1udata0x20;group1datastoredatlocations;startingat0x20.group1_var1res1;group1_var1locatedat0x20.group1_var2res1;group1_var2locatedat0x21.group2udata;Declarationofgroup2data.The;addressesforvariablesundergroup2_var1res1;thisdatasectionareallocatedgroup2_var2res1;automaticallybythelinker.RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin



;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginningofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalongstart;withdirective'CODE'.bankselgroup1_var1clrfgroup1_var1clrfgroup1_var2bankselgroup2_var1clrfgroup2_var1clrfgroup2_var2goto$service_intretfieend



UDATA_ACSExample


udata_acs


Thisprogramdemonstratestheutilityoftheudata_acsdirective,whichisusedwhengeneratinganobjectfile.Thisdirectivedeclaresthebeginningofasectionofuninitializeddata.


listp=18c452;Selectdevice.#include<p18c452.inc>;Includestandardheaderfile;fortheselecteddevice.group1udata_acs0x20;group1datastoredataccess;RAMlocationsstartingat0x20.group1_var1res1;group1_var1locatedat0x20.group1_var2res1;group1_var2locatedat0x21.group2udata_acs;Declarationofgroup2data.The;addressesfordataunderthis;sectonareallocated;automaticallybythelinker.group2_var1res1;Alladdressesbewillallocatedgroup2_var2res1;inaccessRAMspaceonly.RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'INTRTCODEH'8';ThecodesectionnamedINTRTis



;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalong;withdirective'CODE'.startclrfgroup1_var1,A;group1_var1initializedtozeroclrfgroup1_var2,A;group1_var2initializedtozeroclrfgroup2_var1,A;group2_var1initializedtozeroclrfgroup2_var2,A;group2_var2initializedtozerogoto$service_intretfieend



UDATA_OVRExample


udata_ovr


Thisprogramdemonstratestheutilityoftheudata_ovrdirective,whichisusedwhengeneratinganobjectfile.Thisdirectivedeclaresthebeginningofasectionofoverlayeduninitializeddata.


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.same_varudata_ovrH'20';Declaresanoverlayed;uninitializeddatasection;named'same_var'startingatvar1res1;locationH'20'.same_varudata_ovrH'20';Declaresanoverlayed;uninitializeddatasectionvar2res1;withthesamenameastheone;declaredabove.Thusvariables;var1andvar2areallocated;atthesameaddress.RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedincode;sectionRST.gotostart;Jumpstothelocationlabelled;'start'.



INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplacedin;codesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginingofthecode;sectionnamedPGM.Itisa;relocatablecodesection;sincenoabsoluteaddressisgiven;alongwithdirective'CODE'startbankselvar1;Anyoperationonvar1affectsmovlwH'FF';var2alsosincebothvariablesmovwfvar1;areoverlaid.comfvar2goto$service_intretfieend



UDATA_SHRExample

DirectiveshighlightedinthisexampleforPIC16FXXXdevicesare:

udata_shr


Thisprogramdemonstratestheutilityoftheudata_shrdirective,whichisusedwhengeneratinganobjectfile.Thisdirectivedeclaresthebeginningofasectionofshareduninitializeddata.ThisdirectiveisusedtodeclarevariablesthatareallocatedinRAMthatissharedacrossallRAMbanks(i.e.unbankedRAM.)


listp=16f877;Selectthedevice.#include<p16f877.inc>;Includestandardheaderfile;fortheselecteddevice.shared_dataudata_shr;Declaresthebeginningofadata;sectionnamed'shareddata',varres1;whichissharedbyallbanks.;'var'isthelocationwhichcan;beaccessedirrespectiveof;bankselbits.bank0_varudata0X20;Declaresbeginningofadatavar0res1;sectionnamed'bank0_var',;whichisinbank0.var0is;allocatedtheaddress0x20.bank1_varudata0xa0;Declaresbeginningofadatavar1res1;sectionnamed'bank1_var',;whichisinbank1.var1is;allocatedtheaddess0xa0bank2_varudata0x120;Declaresbeginningofadata

var2res1;sectionnamed'bank2_var',;whichisinbank2.var2is;allocatedtheaddess0x120bank3_varudata0x1a0;Declaresbeginningofadatavar3res1;sectionnamed'bank3_var',;whichisinbank3.var3is;allocatedtheaddess0x1a0RSTCODEH'0';ThecodesectionnamedRSTis;placedatH'0'.Theinstruction;'gotostart'isplacedin;codesectionRST.gotostart;Jumpstothelocationlabelled;'start'.INTRTCODEH'4';ThecodesectionnamedINTRTis;placedatH'4'.Theinstruction;'gotoservice_int'isplaced;incodesectionINTRT.gotoservice_int;Jumpstothelocationlabelled;'service_int'.PGMCODE;Thisisthebeginningofthecode;sectionnamedPGM.Itisa;relocatablecodesectionsince;noabsoluteaddressisgivenalongstart;withdirective'CODE'.bankselvar0;Selectbank0.movlwH'00'movwfvar;varisaccessiblefrombank0.bankselvar1;Selectbank1.movlwH'01'movwfvar;varisaccessiblefrombank1;also.bankselvar2;Selectbank2.movlwH'02'movwfvar;varisaccessiblefrombank2;also.bankselvar3;Selectbank3.movlwH'03'



movwfvar;varisaccessiblefrombank3;also.goto$service_intretfieend

Documents

MPASM Assembler Help · Assembler Migration Path Since MPASM assembler is a universal assembler for all PICmicro MCU devices, an application developed for the PIC16C54 can be easily