Altera IP Compiler for PCI Express - Manual (Page 313)

August 2014 Altera Corporation IP Compiler for PCI Express User Guide
A. Transaction Layer Packet (TLP) Header
Formats
TLP Packet Format without Data Payload
Table A–2 through A–3 show the header format for TLPs without a data payload.
When these headers are transferred to and from the IP core as tx_desc and rx_desc,
the mapping shown in
Table A–1 is used
Table A–1. Header Mapping
Header Byte tx_desc/rx_desc Bits
Byte 0 127:120
Byte 1 119:112
Byte 2 111:104
Byte 3 103:96
Byte 4 95:88
Byte 5 87:80
Byte 6 79:72
Byte 7 71:64
Byte 8 63:56
Byte 9 55:48
Byte 10 47:40
Byte 11 39:32
Byte 12 31:24
Byte 13 23:16
Byte 14 15:8
Byte 15 7:0
Table A–2. Memory Read Request, 32-Bit Addressing
+0 +1 +2 +3
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
Byte 0 0 0 0 0 0 0 0 0 0 TC 0 0 0 0 TD EP Attr 0 0 Length
Byte 4 Requestor ID Tag Last BE First BE
Byte 8 Address[31:2] 0 0
Byte 12 Reserved
Table A–3. Memory Read Request, Locked 32-Bit Addressing
+0 +1 +2 +3
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
Byte 0 0 0 0 0 0 0 0 1 0 TC 0 0 0 0 TD EP Attr 0 0 Length
Byte 4 Requestor ID Tag Last BE First BE
August 2014