Word Swap Non-Frame Data = 0 And Byte Swap Non-Frame Data = 0; Word Swap Non-Frame Data = 1 And Byte Swap Non-Frame Data = 0; Word Swap Non-Frame Data = 0 And Byte Swap Non-Frame Data = 1; Table 70: Send Buffer Descriptor (Little-Endian 32-Bit Format) With No Swapping - Broadcom NetXtreme/NetLink BCM5718 Series Programmer's Manual

BCM5718 Programmer's Guide

Word Swap Non-Frame Data = 0 and Byte Swap Non-Frame Data = 0

This would require the software to use the following little-endian data structure on the host:

Table 70: Send Buffer Descriptor (Little-Endian 32-Bit format) with No Swapping

Byte #
Bit # 31
MSB
MSB
In this case, the data structure takes on a slightly new format because the words have been swapped.

Word Swap Non-Frame Data = 1 and Byte Swap Non-Frame Data = 0

This requires the software to use the following little-endian data structure on the host:

Table 71: Send Buffer Descriptor (Little-Endian 32-Bit format) with Word Swapping

Byte #
Bit # 31
MSB
MSB
The disadvantage of this approach is if the host operating system supported a 64-bit data type for a physical
address, the host device driver would have to swap the two 32-bit words that comprise the 64-bit address that
the host operating system used.

Word Swap Non-Frame Data = 0 and Byte Swap Non-Frame Data = 1

This requires the software to use the following big-endian data structure on the host:

Table 72: Send Buffer Descriptor (Big-Endian 32-bit format) with Byte Swapping

Byte #
Bit # 31
MSB
MSB
Broadcom
®
January 29, 2016 • 5718-PG108-R
3 2
Reserved
Length
3
Length
Reserved
0
Reserved
Length
1
15
Host Address
2 1
15
Host Address
1 2
15
Host Address
Endian Control (Byte and Word Swapping)
0
VLAN
Flags
0
Flags
VLAN
3
VLAN
Flags
0x00
0x04
0x08
0x0C
0x00
0x04
0x08
0x0C
0x00
0x04
0x08
0x0C
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