Intel 82559 ユーザーズマニュアル

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10/100 Mbps Ethernet Controller Family Open Source Software Developer Manual  
155
 
 
82550 and 82551QM Specific 
Information
B
This appendix applies to the Intel
®
 82550 and 82551QM devices.
B.1
IPCB
The IP command block (IPCB) is new and used to activate the new offloading features of the 
82550 and 82551. The value of the command field for IPCB is 9h. The relevant aspects of the 
IPCB for each feature is described in the following subsections. This section summarizes the most 
useful combinations of the IPCB fields.
NOTE: Source address insertion is not allowed when IPCB is used. Thus, the no source address insertion 
(NSAI) bit of the configure command must be 1.
Table 69.  IPCB Structure
Odd Word (D31:D16)
Even Word (D15:D0)
Offset
E
L
S
I
CID (5 bits)
000
N
C CMD = 1001
C X O
K U
XXXX XXXX XXXX (12 bits)
0h
Link Address (32 bits)
4h
TBD Array Address (32 bits)
8h
Maximum TCP Payload
E
O
F
0
IPCB Byte Count (14 bits)
Ch
TBD Number
Transmit Threshold
IP Activation (12 bits)
Activation (20 bits)
10h
TCP Header Offset (8 bits)
IP Header Offset (8 bits)
VLAN (16 bits)
14h
Transmit Buffer #0 Address (32 bits)
18h
Reserved (32 bits)
Total TCP Payload (16 bits)
E
L
0
Transmit Buffer #0 Size (14 bits)
1Ch
Reserved (14 bits)
Table 70.  IP Activation Bits (Byte 13)
15
14
13
12
11
10
9
8
0
0
0
Scheduled 
Send
Reserved
Reserved
Insert 
VLAN
Hardware 
Parse
Table 71.  IP Activation Bits (Byte 12)
7
6
5
4
3
2
1
0
Large Send
TCP/UDP 
Number
TCP/UDP 
Checksum
IP 
Checksum
X
X
X
X