
27
PC8260PowerQUICCII
2131B–HIREL–02/03
LWE[0:3]
LSDDQM[0:3]
LBS[0:3]
LocalBusWriteEnable
O
ThewriteenablepinsareoutputsoftheLocalbusGPCM.Thesepins
selectspecificbytelanesforwriteoperations.
LocalBusSDRAMDQM
O
TheDQMpinsareoutputsoftheSDRAMcontrolmachine.Thesepins
selectspecificbytelanesofSDRAMdevices.
LocalBusUPMbyteselect
O
ThebyteselectpinsareoutputsoftheUPMinthememorycontroller.
Theyareusedtoselectspecificbytelanesduringmemoryoperations.
ThetimingofthesepinsisprogrammedintheUPM.Theactualdriven
valuedependsontheaddressandsizeofthetransactionandtheport
sizeoftheaccesseddevice.
LSDA10
LGPL0
LocalBusSDRAMA10
O
Outputfromthe60xbusSDRAMcontroller.Thispinispartofthe
addresswhenarowaddressisdrivenandispartofthecommandwhen
acolumnaddressisdriven.
LocalBusUPMGeneral
PurposeLine0
O
ThisisoneofsixgeneralpurposeoutputlinesfromtheUPM.Thevalues
andtimingofthispinareprogrammedintheUPM.
LSDWE
LGPL1
LocalBusSDRAMWrite
Enable
O
OutputfromthelocalbusSDRAMcontroller.Thispinshouldbe
connectedtoSDRAM’sWEinput.
LocalBusUPMGeneral
PurposeLine1
O
ThisisoneofsixgeneralpurposeoutputlinesfromtheUPM.Thevalues
andtimingofthispinareprogrammedintheUPM.
LOE
LSDRAS
LGPL2
LocalBusOutputEnable
O
TheoutputenablepinisanoutputoftheLocalbusGPCM.Thispin
controlstheoutputbufferofmemorydevicesduringreadoperations.
LocalBusSDRAMRAS
O
OutputfromtheLocalbusSDRAMcontroller.Thispinshouldbe
connectedtotheSDRAMRASinput.
LocalbusUPMGeneral
PurposeLine2
O
ThisisoneofsixgeneralpurposeoutputlinesfromUPM.Thevalues
andtimingofthispinareprogrammedintheUPM.
LSDCAS
LGPL3
LocalBusSDRAMCAS
O
OutputfromtheLocalbusSDRAMcontroller.Thispinshouldbe
connectedtoSDRAM’sCASinput.
LocalBusUPMGeneral
PurposeLine3
O
ThisisoneofsixgeneralpurposeoutputlinesfromtheUPM.Thevalues
andtimingofthispinareprogrammedintheUPM.
LGTA
LUPWAIT
LGPL4
LPBS
LocalBusGPCMTA
I
ThisinputpinisusedfortransactionterminationduringGPCM
operation.Thispinrequiresanexternalpullupresistorforproper
operation.
LocalBusUPMWait
I
ThisisaninputtotheUPM.Anexternaldevicemayholdthispinlowto
forcetheUPMtowaituntilthedeviceisreadyforthecontinuationofthe
operation.
LocalBusUPMGeneral
PurposeLine4
O
ThisisoneofsixgeneralpurposeoutputlinesfromUPM.Thevalues
andtimingofthispinisprogrammedintheUPM.
LocalBusParityByte
Select
O
Insystemsinwhichthedataparityisstoredinaseparatechip,this
outputisusedasthebyteselectforthatchip.
LGPL5
LocalBusUPMGeneral
PurposeLine5
O
ThisisoneofsixgeneralpurposeoutputlinesfromtheUPM.Thevalues
andtimingofthispinareprogrammedintheUPM.
LWR
LocalWrite
O
Thelocalwritepinisanoutputfromthelocalbusmemorycontroller.Itis
usedtodistinguishbetweenreadandwritetransactions.
Table4.
ExternalSignals(Continued)
Pin
SignalName
Type
Description