TMS320x280x Analog to Digital Converter (ADC - Texas Instruments

46 Pages·2010·0.21 MB·English

TMS320x280x, 2801x, 2804x DSP
Analog-to-Digital Converter (ADC)
Reference Guide
LiteratureNumber:SPRU716D
November2004–RevisedApril2010
2 SPRU716D–November2004–RevisedApril2010
Copyright©2004–2010,TexasInstrumentsIncorporated
Contents
Preface ....................................................................................................................................... 7
1 Analog-to-DigitalConverter(ADC) ....................................................................................... 11
1.1 Features .................................................................................................................... 12
1.2 AutoconversionSequencerPrincipleofOperation .................................................................... 14
1.2.1 SequentialSamplingMode...................................................................................... 15
1.2.2 SimultaneousSamplingMode .................................................................................. 15
1.3 UninterruptedAutosequencedMode ................................................................................... 21
1.3.1 SequencerStart/StopMode(SequencerStart/StopOperationWithMultipleTime-Sequenced
Triggers) ........................................................................................................... 23
1.3.2 SimultaneousSamplingMode .................................................................................. 25
1.3.3 InputTriggerDescription ........................................................................................ 25
1.3.4 InterruptOperationDuringSequencedConversions ........................................................ 26
1.4 ADCClockPrescaler...................................................................................................... 28
1.4.1 ADC-moduleClockandSampleRate ......................................................................... 28
1.5 Low-powerModes ......................................................................................................... 28
1.6 Power-upSequence ...................................................................................................... 28
1.7 SequencerOverrideFeature ............................................................................................. 29
1.8 Internal/ExternalReferenceVoltageSelection ........................................................................ 30
1.9 OffsetErrorCorrection .................................................................................................... 31
2 ADCRegisters .................................................................................................................. 33
2.1 ADCControlRegisters.................................................................................................... 34
2.2 MaximumConversionChannelsRegister(ADCMAXCONV) ........................................................ 38
2.3 AutosequenceStatusRegister(ADCASEQSR) ....................................................................... 40
2.4 ADCStatusandFlagRegister(ADCST) ............................................................................... 41
2.5 ADCReferenceSelectRegister(ADCREFSEL) ...................................................................... 42
2.6 ADCOffsetTrimRegister(ADCOFFTRIM) ............................................................................ 42
2.7 ADCInputChannelSelectSequencingControlRegisters........................................................... 43
2.8 ADCConversionResultBufferRegisters(ADCRESULTn) .......................................................... 44
A RevisionHistory ................................................................................................................ 45
SPRU716D–November2004–RevisedApril2010 Contents 3
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List of Figures
1-1. BlockDiagramoftheADCModule...................................................................................... 13
1-2. SequentialSamplingMode(SMODE=0)............................................................................. 15
1-3. SimultaneousSamplingMode(SMODE=1) ........................................................................... 16
1-4. BlockDiagramofAutosequencedADCinCascadedMode ........................................................ 17
1-5. BlockDiagramofAutosequencedADCWithDualSequencers .................................................... 18
1-6. FlowChartforUninterruptedAutosequencedMode.................................................................. 23
1-7. ExampleofePWMTriggerstoStarttheSequencer ................................................................. 24
1-8. InterruptOperationDuringSequencedConversions ................................................................ 27
1-9. ADCCoreClockandSample-and-Hold(S/H)Clock................................................................. 28
1-10. ClockChaintotheADC.................................................................................................. 28
1-11. ExternalBiasfor2.048-VExternalReference......................................................................... 30
1-12. FlowChartofOffsetErrorCorrectionProcess........................................................................ 31
1-13. IdealCodeDistributionofSampled0-VReference................................................................... 32
2-1. ADCControlRegister1(ADCTRL1)(AddressOffset00h).......................................................... 34
2-2. ADCControlRegister2(ADCTRL2)(AddressOffset01h).......................................................... 35
2-3. ADCControlRegister3(ADCTRL3)(AddressOffset18h).......................................................... 37
2-4. MaximumConversionChannelsRegister(ADCMAXCONV)(OffsetAddress02h) ............................. 38
2-5. AutosequenceStatusRegister(ADCASEQSR)(AddressOffset07h)............................................. 40
2-6. ADCStatusandFlagRegister(ADCST)(AddressOffset19h)..................................................... 41
2-7. ADCReferenceSelectRegister(ADCREFSEL)(AddressOffset1Ch)............................................ 42
2-8. ADCOffsetTrimRegister(ADCOFFTRIM)(AddressOffset1Dh).................................................. 42
2-9. ADCInputChannelSelectSequencingControlRegisters(ADCCHSELSEQ1)(AddressOffset03h)........ 43
2-10. ADCInputChannelSelectSequencingControlRegisters(ADCCHSELSEQ2)(AddressOffset04h)........ 43
2-11. ADCInputChannelSelectSequencingControlRegisters(ADCCHSELSEQ3)(AddressOffset05h)........ 43
2-12. ADCInputChannelSelectSequencingControlRegisters(ADCCHSELSEQ4)(AddressOffset06h)........ 43
2-13. ADCConversionResultBufferRegisters(ADCRESULTn)-(Addresses0x7108-0x7117)..................... 44
2-14. ADCConversionResultBufferRegisters(ADCRESULTn)-(Addresses0x0B00-0x0B0F) .................... 44
4 ListofFigures SPRU716D–November2004–RevisedApril2010
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List of Tables
1-1. ADCRegisters............................................................................................................. 13
1-2. ComparisonofSingleandCascadedOperatingModes ............................................................ 19
1-3. ValuesforADCCHSELSEQnRegisters(MAX_CONV1Setto6).................................................. 22
1-4. ValuesforADCCHSELSEQn(MAX_CONV1setto2)............................................................... 24
1-5. ValuesAfterSecondAutoconversionSession ........................................................................ 25
1-6. InputTriggers.............................................................................................................. 25
1-7. PowerOptions............................................................................................................. 28
2-1. ADCControlRegister1(ADCTRL1)FieldDescriptions............................................................. 34
2-2. ADCControlRegister2(ADCTRL2)FieldDescriptions............................................................. 35
2-3. ADCControlRegister3(ADCTRL3)FieldDescriptions............................................................. 37
2-4. MaximumConversionChannelsRegister(ADCMAXCONV)FieldDescriptions.................................. 38
2-5. BitSelectionsforMAX_CONV1forVariousNumberofConversions ............................................. 38
2-6. AutosequenceStatusRegister(ADCASEQSR)FieldDescriptions................................................. 40
2-7. StateofActiveSequencer ............................................................................................... 40
2-8. ADCStatusandFlagRegister(ADCST)FieldDescriptions......................................................... 41
2-9. ADCReferenceSelectRegister(ADCREFSEL)FieldDescriptions................................................ 42
2-10. ADCOffsetTrimRegister(ADCOFFTRIM)FieldDescriptions...................................................... 42
2-11. CONVnnBitValuesandtheADCInputChannelsSelected ........................................................ 43
A-1. ChangesinthisRevision................................................................................................. 45
SPRU716D–November2004–RevisedApril2010 ListofTables 5
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6 ListofTables SPRU716D–November2004–RevisedApril2010
Copyright©2004–2010,TexasInstrumentsIncorporated
Preface
SPRU716D–November2004–RevisedApril2010
Read This First
About This Manual
Thisdocumentdescribesthefeaturesandoperationoftheanalog-to-digitalconverter(ADC)thatis
availableontheTMS320x280x,2801x,and2804xdigitalsignalprocessors(DSPs).
Notational Conventions
Thisdocumentusesthefollowingconventions.
• ThedevicenumberTMS320x280xisoftenabbreviatedas280x.
• Hexadecimalnumbersareshownwiththesuffixh.Forexample,thefollowingnumberis40
hexadecimal(decimal64):40h.Similarly,binarynumbersoftenareshownwith thesuffixb.For
example,thefollowingnumberisthedecimal4showninbinaryform:0100b
• Registersinthisdocumentareshowninfiguresanddescribedintables.
– Eachregisterfigureshowsarectangledividedintofieldsthat representthefieldsoftheregister.
Eachfieldislabeledwithitsbitname, itsbeginningandendingbitnumbersabove,andits
read/writepropertiesbelow.Alegendexplainsthenotationusedfor theproperties.
– Reservedbitsinaregisterfiguredesignateabit that cannotbeusedfor applications.
• Ifasignalisactivelow,ithasanoverbar. Forexample,theXRSsignalisactivelow.
Related Documentation From Texas Instruments
Thefollowingdocumentsdescribethe280xdevicesandrelatedsupport tools.Copiesofthesedocuments
areavailableontheInternetatwww.ti.com.Tip:Entertheliteraturenumberinthesearchboxprovided at
www.ti.com.
DataManuals—
SPRS230— TMS320F2809,F2808,F2806,F2802,F2801,C2802,C2801,andF2801xDSPsData
Manualcontainsthepinout,signaldescriptions,aswellaselectricalandtimingspecificationsfor
theF280xdevices.
SPRZ171— TMS320F280x,TMS320C280x, andTMS320F2801xDSCSiliconErrata
describestheadvisoriesandusagenotesfor differentversionsofsilicon.
SPRS357— TMS320F28044DigitalSignalProcessorDataManualcontainsthepinout,signal
descriptions,aswellaselectricalandtimingspecificationsfor theF28044device.
SPRZ255— TMS320F28044DSP SiliconErrata
describestheadvisoriesandusagenotesfor differentversionsofsilicon.
CPUUser'sGuides—
SPRU051— TMS320x28xx,28xxxSerialCommunicationInterface(SCI)ReferenceGuide describesthe
SCI,whichisatwo-wireasynchronousserialport,commonlyknownasaUART. TheSCI modules
supportdigitalcommunicationsbetweentheCPUandother asynchronousperipheralsthatuse the
standardnon-return-to-zero(NRZ)format.
SPRU059— TMS320x28xx,28xxxSerialPeripheralInterface(SPI)ReferenceGuide describestheSPI-
ahigh-speedsynchronousserialinput/output(I/O)port -that allowsaserialbitstreamof
programmedlength(onetosixteenbits)tobeshiftedintoandoutofthedeviceataprogrammed
bit-transferrate.
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RelatedDocumentationFromTexasInstruments www.ti.com
SPRU074— TMS320x28xx,28xxxEnhancedControllerAreaNetwork(eCAN)ReferenceGuide
describestheeCAN thatusesestablishedprotocoltocommunicateseriallywith other controllersin
electricallynoisyenvironments.
SPRU430— TMS320C28xDSPCPUandInstructionSetReferenceGuidedescribesthecentral
processingunit(CPU)andtheassemblylanguageinstructionsoftheTMS320C28xfixed-point
digitalsignalprocessors(DSPs).It alsodescribesemulationfeaturesavailableontheseDSPs.
SPRU513— TMS320C28xAssemblyLanguageToolsUser'sGuide describestheassemblylanguage
tools(assemblerandothertoolsusedtodevelopassemblylanguagecode), assemblerdirectives,
macros,commonobjectfileformat,andsymbolicdebuggingdirectivesfor theTMS320C28xdevice.
SPRU514— TMS320C28xOptimizingCCompilerUser'sGuide describestheTMS320C28x™C/C++
compiler.ThiscompileracceptsANSIstandardC/C++sourcecodeandproducesTMS320DSP
assemblylanguagesourcecodefor theTMS320C28xdevice.
SPRU566— TMS320x28xx,28xxxPeripheralReferenceGuide describestheperipheralreferenceguides
ofthe28xdigitalsignalprocessors(DSPs).
SPRU608— TheTMS320C28xInstructionSetSimulatorTechnicalOverview describesthesimulator,
availablewithintheCodeComposerStudiofor TMS320C2000IDE,that simulatestheinstruction
setoftheC28x™core.
SPRU625— TMS320C28xDSP/BIOSApplicationProgrammingInterface(API)ReferenceGuide
describesdevelopmentusingDSP/BIOS.
SPRU712— TMS320x28xx,28xxxSystemControlandInterruptsReferenceGuidedescribesthe various
interruptsandsystemcontrolfeaturesofthe280xdigitalsignalprocessors(DSPs).
SPRU721— TMS320x28xx,28xxxInter-IntegratedCircuit(I2C)ModuleReferenceGuidedescribes
thefeaturesandoperationoftheinter-integratedcircuit (I2C) module.
SPRU722— TMS320x280x,2801x,2804xBootROMReferenceGuidedescribesthepurpose and
featuresofthebootloader(factory-programmedboot-loadingsoftware).It alsodescribesother
contentsofthedeviceon-chipbootROMandidentifieswherealloftheinformationislocatedwithin
thatmemory.
SPRU790— TMS320x280x,2801x,2804xEnhancedQuadratureEncoderPulse(eQEP) Module
ReferenceGuidedescribestheeQEPmodule,whichisusedfor interfacingwith alinearorrotary
incrementalencodertogetposition, direction,andspeedinformationfromarotatingmachine in
highperformancemotionandpositioncontrolsystems.It includesthemoduledescriptionand
registers
SPRU791— TMS320x28xx,28xxxEnhancedPulseWidthModulator(ePWM) ModuleReference Guide
describesthemainareasoftheenhancedpulsewidthmodulatorthat includedigitalmotorcontrol,
switchmodepowersupplycontrol,UPS(uninterruptiblepower supplies), andother formsof power
conversion
SPRU807— TMS320x280x,2801x,2804xEnhancedCapture (eCAP)ModuleReferenceGuide
describestheenhancedcapture module.It includesthemoduledescriptionandregisters.
SPRU924— TMS320x280x,2801x,2804xHigh-ResolutionPulseWidthModulatorReference Guide
describestheoperationofthehigh-resolutionextensiontothepulsewidthmodulator(HRPWM).
ApplicationReports—
SPRAA58— TMS320x281xtoTMS320x280xMigrationOverviewdescribesdifferencesbetweenthe
TexasInstrumentsTMS320x281xandTMS320x280xDSPstoassist inapplicationmigrationfrom
the281xtothe280x.Whilethemainfocusofthisdocumentismigrationfrom281xto280x, users
consideringmigratinginthereversedirection(280xto281x)willalsofindthisdocumentuseful.
8 ReadThisFirst SPRU716D–November2004–RevisedApril2010
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www.ti.com RelatedDocumentationFromTexasInstruments
SPRA550— 3.3VDSPforDigitalMotorControl describesascenarioofa3.3-V-onlymotorcontroller
indicatingthatformostapplications,nosignificantissueofinterfacingbetween3.3Vand5V
exists.On-chip3.3-V analog-to-digitalconverter(ADC)versus5-VADCisalsodiscussed.
Guidelinesforcomponentlayoutandprintedcircuit board(PCB) designthat canreducesystem
noiseandEMIeffectsaresummarized.
SPRA820— OnlineStackOverflowDetectionontheTMS320C28xDSPpresentsthemethodologyfor
onlinestackoverflowdetectionontheTMS320C28x™DSP.C-sourcecodeisprovidedthat
containsfunctionsforimplementingtheoverflowdetectiononbothDSP/BIOS™and
non-DSP/BIOSapplications.
SPRA861— RAMDISK:ASampleUser-DefinedCI/ODriverprovidesaneasywaytousethe
sophisticatedbufferingofthehigh-levelCIO functionsonanarbitrarydevice. Thisapplicationreport
presentsasampleimplementationofauser-defineddevicedriver.
SPRA873— Thermo-ElectricCoolerControlUsingaTMS320F2812DSP &DRV592PowerAmplifier
presentsathermoelectriccoolersystem consistingofaTexasInstrumentsTMS320F2812 digital
signalprocessor(DSP)andDRV592power amplifier. TheDSPimplementsadigital
proportional-integral-derivativefeedbackcontrollerusinganintegrated12-bitanalog-to-digital
convertertoreadthethermistor, anddirectoutput ofpulse-width-modulatedwaveformsto the
H-bridgeDRV592poweramplifier.Acompletedescriptionoftheexperimentalsystem,along with
softwareandsoftwareoperatinginstructions, isprovided.
SPRA876— ProgrammingExamplesfor theTMS320F281xeCANcontainsseveralprogramming
examplestoillustratehowtheeCANmoduleissetupfor differentmodesofoperationtohelpyou
comeuptospeedquicklyinprogrammingtheeCAN.AllprojectsandCANalyzerconfigurationfiles
areincludedintheattachedSPRA876.zipfile.
SPRA953— ICPackageThermal Metricsdescribesthetraditionalandnewthermalmetricsandwillput
theirapplicationinperspectivewithrespect tosystem leveljunctiontemperatureestimation.
SPRA958— RunninganApplicationfromInternalFlashMemoryontheTMS320F281xDSP(Rev. B)
coverstherequirementsneededtoproperlyconfigureapplicationsoftwarefor executionfrom
on-chipflashmemory. Requirementsfor bothDSP/BIOS™andnon-DSP/BIOSprojectsare
presented.Examplecodeprojectsareincluded.
SPRA963— ReliabilityDataforTMS320LF24xandTMS320F281xDevices describesreliability data for
TMS320LF24xandTMS320F281xdevices.
SPRA989— F2810,F2811,andF2812ADCCalibration describesamethodfor improving theabsolute
accuracyofthe12-bitanalog-to-digitalconverter(ADC)foundontheF2810/F2811/F2812devices.
Thisapplicationnoteisaccompaniedbyanexampleprogram (ADCcalibration.zip)that executes
fromRAMontheF2812eZdsp.
SPRA991— SimulationFulfillsitsPromisefor EnhancingDebugandAnalysis-AWhitePaperdescribes
simulationenhancementsthatenabledeveloperstospeedupthedevelopmentcycle byallowing
themtoevaluatesystemalternativesmore effectively.
TMS320C28x,C28xaretrademarksofTexasInstruments.
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