Texas Instruments TMS320TCI648x Network Card User Manual


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double-word0
4
double-wordn-1
acklD rsv
prio
tt ftype
destID
sourcelD
address
rsrv
xamsbs
double-word1
...
double-wordn-2
CRC
PHY
LOG
TRA
LOG
TRA
PHY
5
3
2
2
8
8
29
1
2
64 64
(n-4)*64
64
64
16
16
n*64+32
16
4
2
10
LOG
PHY
10
TRA
2 4
9 * 6 4 + 32
LOG
TRA
16
PHY
16
double-word0
5
acklD sourcelD
rsv
3
prio
2
ftype
tt
2 4
destID
8
1
rsrvaddress
8 29
xamsbs
2
64
double-word8
double-word1
64
5*64
...
64
double-word9
64
CRC
16
LOG
(n-9)*64
16
PHY
double-word10
64
double-wordn-2double-word11
64
(n-13)*64
...
double-wordn-1
6464 16
CRC
n*64+96
n*64+80
PHY =Physicallayer
TRA= Transportlayer
LOG=Logicallayer
2.1.2.3ControlSymbols
SCorPD parameter1stype0 stype1Parameter0 cmd CRC
533553
Delimiter 1stByte 2ndByte 3rdByte
8
SRIOFunctionalDescription
Figure6.1x/4xRapidIOPacketDataStream(Streaming-WriteClass)
Note:Figure6assumesthataddressesare32-bitanddeviceIDsare8-bit.
ThedeviceID,beingan8-bitfield,willaddressupto256nodesinthesystem.If16-bitaddresseswere
used,thesystemcouldaccommodateupto64knodes.
ThedatastreamincludesaCyclicRedundancyCode(CRC)fieldtoensurethedatawascorrectly
received.TheCRCvalueprotectstheentirepacketexcepttheackIDandonebitofthereservedPHY
field.TheperipheralcheckstheCRCautomaticallyinhardware.IftheCRCiscorrect,aPacket-Accepted
controlsymbolissentbythereceivingdevice.IftheCRCisincorrect,aPacket-Not-Acceptedcontrol
symbolissentsothattransmissionmayberetried.
Controlsymbolsarephysicallayermessageelementsusedtomanagelinkmaintenance,packet
delimiting,packetacknowledgment,errorreporting,anderrorrecovery.Alltransmitteddatapacketsare
delimitedbystart-of-packetandend-of-packetdelimiters.SRIOcontrolsymbolsare24bitslongandare
protectedbytheirownCRC(seeFigure7).Controlsymbolsprovidetwofunctions:stype0symbols
conveythestatusoftheporttransmittingthesymbol,andstype1symbolsarerequeststothereceiving
portortransmissiondelimiters.Theyhavethefollowingformat,whichisdetailedinSection3ofthe
RapidIOPhysicalLayer1x/4xLP-SerialSpecification.
Figure7.SerialRapidIOControlSymbolFormat
Controlsymbolsaredelimitedbyspecialcharactersatthebeginningofthesymbol.Ifthecontrolsymbol
containsapacketdelimiter(start-of-packet,end-of-packet,etc.),thespecialcharacterPD(K28.3)isused.
Ifthecontrolsymboldoesnotcontainapacketdelimiter,thespecialcharacterSC(K28.0)isused.This
useofspecialcharactersprovidesanearlywarningofthecontentsofthecontrolsymbol.TheCRCdoes
notprotectthespecialcharacters,butanillegalorinvalidcharacterisrecognizedandflaggedas
Packet-Not-Accepted.Sincecontrolsymbolsareknownlength,theydonotneedenddelimiters.
24SerialRapidIO(SRIO)SPRUE13A–September2006
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