标签: plls

AlteraPowerCalculatorUserGuide……

UsingPLLsinCycloneDevices……

【应用手册】AN578:ManualPlacementofCMUPLLsandATXPLLsinStratixIVGXandGTDevicesThisapplicationnotedescribesthestepsinvolvedinthemanualplacementofCMUphase-lockedloops(PLLs)andATXPLLsinAltera’sStratix®IVGXandGTFPGAs.Altera’sQuartus®IIsoftwareautomaticallyplacestheCMUPLLsandATXPLLsbydefault.ThedefaultplacementofCMUPLLsbytheQuartusIIsoftwaremaynotbeoptimumforallbondedconfigurations,exceptforthePCIExpress(PIPE)×8bondedconfigurationandtheBasic×8bondedconfiguration.CheckthedefaultplacementtodecideifitisoptimumforskewrequirementsinyourBasic(PMADirect)×Nbondeddesign.Ifitisnot,manualplacementoftheCMUPLLsisrecommended.ThedefaultplacementofATXPLLsbytheQuartusIIsoftwareisperformedarbitrarilyforallbondedconfigurations,exceptforthePCIExpress(PIPE)×8bondedconfiguration.Checkthedefaultplacementtodecideifitisoptimumforskewrequirementsinyourdesign.Ifitisnot,manualplacementoftheATXPLLsisrecommended.ThisapplicationnoteusestheBasic(PMADirect)xNbondedconfigurationasanexamplescenario,whereskewisacriticalparameterandisdependentonthelocationofthetransmitterPLL(CMUPLLorATXPLL).AN578:ManualPlacementofCMUPLLsandATXPLLsinStratixIVGXandGTDevicesMay2009AN-578-1.0IntroductionThisapplicationnotedescribesthestepsinvolvedinthemanualplacementofCMUphase-lockedloops(PLLs)andATXPLLsinAltera’sStratixIVGXandGTFPGAs.Altera’sQuartusIIsoftwareautomaticallyplacestheCMUPLLsandATXPLLsbydefault.Thedefaultplacement……