Altera 40-Gbps Ethernet MAC and PHY MegaCore Function User Manual
Page 65
Figure 3-16: Byte Order on the Avalon-ST Interface Lanes With Preamble Pass‑Through
Describes the byte order on the Avalon-ST interface when the preamble pass-through feature is turned
on. Recall that the IP core overwrites the Start byte you provide on the client interface, but does not
overwrite the SFD byte.
Destination Address[40] is the broadcast/multicast bit (a type bit), and Destination Address[41] is a
locally administered address bit.
SFD
Preamble Start
Destination Address
(DA)
Data (D)
Source Address (SA)
Type/
Length
Octet 7 6 5 4 3 2 1 0 5 4 3 2 1 0 5 4 3 2 1 0 1 0 00 ... NN
Bit
[63:56]
[55:48]
[47:40]
[39:32]
[31:24]
[23:16]
[15:8]
[7:0]
[47:40]
[39:32]
[31:24]
[23:16]
[15:8]
[7:0]
[47:40]
[39:32]
[31:24]
[23:16]
[15:8]
[7:0]
[15:8]
[7:0]
MSB[7:0]
...
LSB[7:0]
3-18
Order of Transmission
UG-01088
2014.12.15
Altera Corporation
Functional Description