2.10.8PromiscuousReceiveMode
Architecture
WhenthepromiscuousreceivemodeisenabledbysettingtheRXCAFENbitinthereceive
multicast/broadcast/promiscuouschannelenableregister(RXMBPENABLE),nonaddressmatchingframes
thatwouldnormallybefilteredaretransferredtothepromiscuouschannel.Addressmatchingframesthat
wouldnormallybefilteredduetoerrorsaretransferredtotheaddressmatchchannelwhentheRXCAFEN
andRXCEFENbitsinRXMBPENABLEareset.Aframeisconsideredtobeanaddressmatchingframe
onlyifitisenabledtobereceivedonaunicast,multicast,orbroadcastchannel.Framesreceivedto
disabledunicast,multicast,orbroadcastchannelsareconsiderednonaddressmatching.
MACcontrolframesaddressmatchonlyiftheRXCMFENbitinRXMBPENABLEisset.TheRXCEFEN
andRXCSFENbitsinRXMBPENABLEdeterminewhethererrorframesaretransferredtomemoryornot,
buttheydonotdeterminewhethererrorframesareaddressmatchingornot.Shortframesareaspecial
typeoferrorframes.
AsinglechannelisselectedasthepromiscuouschannelbytheRXPROMCHbitinRXMBPENABLE.The
promiscuousreceivemodeisenabledbytheRXCMFEN,RXCEFEN,RXCSFEN,andRXCAFENbitsin
RXMBPENABLE.Table6showstheeffectsofthepromiscuousenablebits.Properframesareframes
thatarebetween64bytesandthevalueinthereceivemaximumlengthregister(RXMAXLEN)bytesin
lengthinclusiveandcontainnocode,align,orCRCerrors.
Table6.ReceiveFrameTreatmentSummary
AddressMatchRXCAFENRXCEFENRXCMFENRXCSFENReceiveFrameTreatment
00XXXNoframestransferred.
01000Properframestransferredtopromiscuouschannel.
01001Proper/undersizeddataframestransferredto
promiscuouschannel.
01010Properdataandcontrolframestransferredto
promiscuouschannel.
01011Proper/undersizeddataandcontrolframes
transferredtopromiscuouschannel.
01100Proper/oversize/jabber/code/align/CRCdataframes
transferredtopromiscuouschannel.Nocontrolor
undersized/fragmentframesaretransferred.
01101Proper/undersized/fragment/oversize/jabber/code/
align/CRCdataframestransferredtopromiscuous
channel.Nocontrolframesaretransferred.
01110Proper/oversize/jabber/code/align/CRCdataand
controlframestransferredtopromiscuouschannel.
Noundersizedframesaretransferred.
01111Allnonaddressmatchingframeswithandwithout
errorstransferredtopromiscuouschannel.
1X000Properdataframestransferredtoaddressmatch
channel.
1X001Proper/undersizeddataframestransferred
toaddressmatchchannel.
1X010Properdataandcontrolframestransferredto
addressmatchchannel.
1X011Proper/undersizeddataandcontrolframes
transferredtoaddressmatchchannel.
1X100Proper/oversize/jabber/code/align/CRCdataframes
transferredtoaddressmatchchannel.Nocontrol
orundersizedframesaretransferred.
1X101Proper/oversize/jabber/fragment/undersized/code/
align/CRCdataframestransferredtoaddress
matchchannel.Nocontrolframesaretransferred.
EthernetMediaAccessController(EMAC)/ManagementDataInput/Output(MDIO) 48SPRUEQ6–December2007
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