Design in Common for the R4200_R4600_R4000PC and R4400PC

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1、1/28DesignincommonfortheR4200(VRX),R4600(Orion),R4000PCandR4400PC=========================================================================Documentdevelopmenthistory:Rev.0.118June'93.Rev.0.28July'93.FirstcustomerreleaseRev.1.011Oct.'93.Rev.1.12Dec.’93.(Formatchangeon

2、ly).ThisdocumentisintendedtoguidesystemdesignerswhowishtodoasinglesystemdesignwhichcanbeusedwitheithertheR4200orR4600processor.Thiswouldallowasystemmanufacturertoproducetwodifferentsystemsatdifferentprice/performancepointsfromasingledesign.Thisispossibledesigningfor

3、eitherthe208-pinQFPpackageofR4200andR4600,orthe179-pinPGApackageofeach.Inthecaseofchoosingthe179-pinpackage,theR4000PCandR4400PCprocessorswillexpandthechoiceandrangeofsystemsmanufacturablefromthesingledesignevenfurther.ItisnotintendedthatR4200/R4600CPU'swouldbeinter

4、changeablebytheuserinsuchadesign.Thisdocumentaddressesthefollowingdifferenceswhichmaybesignificanttosystemdesigners:1/R4200andR4600pin-out(208-pinQFPpackage)2/R4200,R4600,R4000PCandR4400PCpin-out(179-pinPGApackage)3/Primarycachedifferences(R4000PC,R4200,R4600andR440

5、0PC)4/TLBdifferences""5/Pipelinecomparisons""6/SystemInterfacecomparisons""7/Coprocessor0comparison""8/Maximumratings(R4200andR4600(3V))9/Operatingparameters""10/Clockparameters""11/SystemInterfaceparameters""2/281/208-pinQFPpackage======================R4200andR460

6、0signalsarethesamewhereI/Oisconcernedbutdifferentintheareasofprocessorconfigurationandinitialization.Themajorityofpinshaveanidenticalfunction.Thosethathaveadifferencearemarkedwithanote.Wherepossible,conflictingfunctionswereoverlappedwithNoConnectsontheotherprocessor

7、.Thereare16suchcasesmarkedNote1&2.Inafewcases,functionallydifferentpinswerealignedsuchthatinputsoverlapinputsandoutputsoverlapoutputs.Mostofthesecasescanbedealtwithtrivially,ignoringoptionalorunusedfunctionality.Fortheremaining2or3pins(dependsonsettingsofconfigurati

8、onpinsonR4200),itmaybenecessaryeithertohavejumperswhichcanbeset,ordualtraces,oneofwhichwouldfilledatsystemmanufacturetime.Overlappingfunct