WG82574L S LBA8 Intel, WG82574L S LBA8 Datasheet - Page 156

• Manufacturer Part Number: WG82574L S LBA8
• Manufacturer: Intel

Specifications of WG82574L S LBA8

• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: 0C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Compliant

7.2.10.1.7
7.2.10.2
Figure 32.
7.2.10.2.1
156
VLAN Field
The VLAN field is used to provide the 802.1Q/802.1ac tagging information. The VLAN
field is ignored if the VLE bit is 0b or if the EOP bit is 0b.
Context Transmit Descriptor Format
Context Transmit Descriptor Format
The context descriptor provides access to the enhanced checksum off load and TCP
segmentation features available in the 82574.
A context descriptor differs from a data descriptor as it does not point to packet data.
Instead, this descriptor provides access to on-chip contexts that support the transmit
checksum offloading or the segmentation feature of the 82574. A context refers to a
set of parameters loaded or unloaded as a group to provide a particular function.
To select this descriptor format, the DEXT bit in the command field should be set to 1b
and TDESC.DTYP should be set to 0x0000. In this case, the descriptor format is defined
as shown in
IP and TCP/UDP Checksum Control
The first Qword of this descriptor type contains parameters used to calculate the two
checksums, which can be offloaded.
15
PRI
13
Figure
0
8
3
TUCSE
63
MSS
63
CFI
12
2
RSV
32.
Status
1
11
TUCSE, TUCSS, TUCSO are
TCP/UDP Checksum Controls
VLAN tag
DD
0
IDE SNAP DEXT RSV
7
48
48
0
47
47
HDRLEN
6
TUCSO
descriptor format
DEXT must =1
5
for context
Command
40
40
39
RSV
39
4
TUCSS
36 35
RS
STA
3
32
32
TSE
82574 GbE Controller—Inline Functions
31
31
TUCMD
2
IPCSE
IPCSE, IPCSS, IPCSO are IP
Checksum Controls
IP
24
1
23
DTYP
TCP
20
0
16
PAYLEN
19
IPCSO
15
DTYP must =0000
3
descriptor format
for context
DTYP
8
2
IPCSS
7
1
0
0
0