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6ChronosGUI
6.1UsingSoftware-EnabledAutomaticPLLSelection
ChronosGUI
Afterthesetupwizardcompletes,starttheGUIinterfacefromtheStartmenu(Start→Texas
Instruments→ChronosEval→TIChronosGUI.exe).
ConnecttheUSBcabletotheEVM.IfMicrosoftWindowspromptsyouforanappropriatedriver,donot
usetheautomaticsearchoption.Selectamanualinstallation.Whenpromptedforthedriverlocation,
browsetotheChronosGUIfilefolderthatwascreatedduringinstallation.(Iftheoperatingsystemdoes
notaskforadriver,noadditionalactionisneeded.)
OncetheUSBdriverinstallationcompletes,theGUIsoftwareshouldconnectproperlyandbereadyfor
use.AgreenlightintheUSBcommunicationboxindicatesagoodUSBconnection;aredlightindicatesa
faultyUSBconnection.Iftheconnectionisnotestablished,attempttore-installthedrivers.
Figure5showstheChronosGUIusedtonavigatetheEVMsoftware.
Figure5.TIChronosSoftwareGUI
ThesoftwareillustrationFigure5showstheon-chipPLLstructureoftheCDCE421.Throughthisscreen,
theusercanchangetheInputFrequency,PFDChargePump,LoopFilter,andOutputType.Theother
featuresareselectedbythesoftware;user-selectableoptionsaredescribedinthissection.
Step1.ICBlockConfigurationandInputCalculator.
BeforeprogrammingthePLL,thespecificEVMblockthatisbeingprogrammedmustbeselectedin
theICBlockConfigsectionoftheGUI.ForanyblockintheEVMbeingused,thefirstrowof
calculationsisusefulwhentryingtoinvestigatetheinputfrequencytotheCDCE421neededtoobtain
adesiredoutputfrequency.TheinputfrequencyisobtainedbypressingtheCalculatebutton.
Step2.StoreCrystalFrequency.
IfacrystalinputisusedforBlockBoftheEVM,thecrystalfrequencymustbeenteredintothespace
provided;clickontheDevice_EEPROMdrop-downmenuatthetopofthesoftwareGUI.Amenuitem
labeledSaveBlockB–XTALFreqtoEEPROMappears;thismenuitemmustbeselected.Thecrystal
SCAU020–March200710.9MHz–1175MHzLowPhaseNoiseClockEvaluationBoard9
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