Texas Instruments TMS320C6452 DSP Network Card User Manual


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A.3VLYNQ2.0PacketFormat
bytecnt
10bits
cmd2
10bits
cmd1
10bits
address
<4*10bits
data
N*10bits
eop
10bits
pkttype adrmask
VLYNQ2.0PacketFormat
TheVLYNQ2.0packetformatisshowninFigureA-1anddescribedinTableA-3,where0<N<65.
Multi-bytefieldsaretransferredleast-significantbytefirst.
FigureA-1.PacketFormat(10-bitSymbolRepresentation)
TableA-3.PacketFormat(10-bitSymbolRepresentation)Description
FieldValueDescription
PKTTYPE[3:0]Thisfieldindicatesthepackettype.
0000Reserved
0001Writewithaddressincrement.
0010Reserved
0011Write32-bitwordwithaddressincrement.
0100Reserved
0101Configurationwritewithaddressincrement.
0110Reserved
0111Interrupt
1000Reserved
1001Readwithaddressincrement.
1010Reserved
1011Read32-bitwordwithaddressincrement.
1100Reserved
1101Configurationreadwithaddressincrement.
1110ReservedforVLYNQversion2.0andlater.
1111ReadresponseforallVLYNQversions.
ADRMASK[3:0]Indicateswhichbyteoftheaddressisincludedinthepacket.Onlyaddressbytesthathavechanged
sincethepreviousaddresswillbeincluded.Eachbitcorrespondstoonebyteofaddress.
BYTECNT[7:0]Bytecount.Thisfieldindicatesthetotalnumberofbytesinthepacket.Thisfieldisonlyincludedfor
write,read,andconfigurationpackettypes.Allotherpackettypeshavefixedlengthsanddonot
requirethisfield.
ADDRESS[7:0]Addressbyte0.ThisbyteisincludedonlyifADRMASK[0]issetto1.IfADRMASK[0]isclearedto0,
assumethisbyteisequaltobits7:0ofthepreviousaddress.Readresponsepacketsdonotinclude
thisfield.
ADDRESS[15:8]Addressbyte1.ThisbyteisincludedonlyifADRMASK[1]issetto1.IfADRMASK[1]isclearedto0,
assumethisbyteisequaltobits15:8ofthepreviousaddress.Readresponsepacketsdonotinclude
thisfield.
ADDRESS[23:16]Addressbyte2.ThisbyteisonlyincludedifADRMASK[2]issetto1.IfADRMASK[2]isclearedto0,
thisassumethisbyteisequaltobits23:16ofthepreviousaddress.Readresponsepacketsdonot
includethisfield.
ADDRESS[31:24]Addressbyte3.ThisbyteisonlyincludedifADRMASK[3]issetto1.IfADRMASK[3]isclearedto0,
assumethisbyteisequaltobits31:24ofthepreviousaddress.Readresponsepacketsdonot
includethisfield.
DATADatapayload.Themaximumdatapayloadsizeislimitedtosixteen32-bitwordstoallowittofitinthe
RXFIFO.
EOPEndofpacketindicator,/T/.
SPRUF89–October2007VLYNQProtocolSpecifications47
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