
6
PC8260PowerQUICCII
2131B–HIREL–02/03
Communication
ProcessorModule(CPM)
TheCPMcontainsfeaturesthatallowthePC8260toexcelinavarietyofapplications
targetedmainlyfornetworkingandtelecommunicationmarkets.
TheCPMisasupersetofthePC8260PowerQUICCCPM,withenhancementsonthe
CPperformanceandadditionalhardwareandmicrocoderoutinesthatsupporthighbit
rateprotocolslikeATM(upto155Mbpsfull-duplex)andFastEthernet(100Mbpsfull-
duplex).
ThefollowinglistsummarizesthemajorfeaturesoftheCPM:
Thecommunicationsprocessor(CP)isanembedded32-bitRISCcontroller
residingonaseparatebus(CPMlocalbus)fromthe60xbus(usedbythesystem
core).Withthisseparatebus,theCPdoesnotaffecttheperformanceofthe
PowerPCcore.TheCP handlesthelowerlayertasksandDMAcontrolactivities,
leavingthePowerPCcorefreetohandlehigherlayeractivities.TheCPhasan
instructionsetoptimizedforcommunications,butcanalsobeusedforgeneral-
purposeapplications,relievingthesys-temcoreofsmalloftenrepeatedtasks.
TwoserialDMAs(SDMAs)thatcandosimultaneoustransfers,optimizedforburst
transferstothe60xbusandtothelocalbus.
Threefull-duplex,serialfastcommunicationscontrollers(FCCs)supportingATM
(155Mbps)protocolthroughUTOPIA2interface(therearetwoUTOPIAinterfaces
onthePC8260),IEEE802.3andFastEthernetprotocols,HDLCuptoE3rates(45
Mbps)andtotallytransparentoperation.EachFCCcanbeconfiguredtotransmit
fullytransparentandreceiveHDLC,orvice-versa.
Twomultichannelcontrollers(MCCs)thatcanhandleanaggregateof256x64
KbpsHDLCortransparentchannels,multiplexedonuptoeightTDMinterfaces.
TheMCCalsosupportssuper-channelsofrateshigherthan64Kbpsand
subchannelingofthe64-Kbpschannels.
Fourfull-duplexserialcommunicationscontrollers(SCCs)supporting
IEEE802.3/Ethernet,high-levelsynchronousdatalinkcontrol,HDLC,localtalk,
UART,synchronousUART,BISYNCandtransparent.
Twofull-duplexserialmanagementcontrollers(SMC)supportingGCI,UART,and
transparentoperations.
Serialperipheralinterface(SPI)andI
2
Cbuscontrollers.
Time-slotassigner(TSA)thatsupportsmultiplexingofdatafromanyofthefour
SCCs,threeFCCs,andtwoSMCs.
SoftwareCompatibility
Issues
Asmuchaspossible,thePC8260CPMfeaturesweremadesimilartothoseofthepre-
viousdevices(PC860).ThecodeportseasilyfrompreviousdevicestothePC8260,
exceptfornewprotocolssupportedbythePC8260.
Althoughmanyregistersarenew,mostregistersretaintheoldstatusandeventbits,so
anunderstandingoftheprogrammingmodelsofthe68360,PC860,orPC850ishelpful.
NotethatthePC8260initializationcoderequireschangesfromthePC8260initialization
code.