Intel PCI User Manual

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The following list provides explanations of the various PCI registers and their bit fields:

Vendor ID

This uniquely identifies all Intel PCI products. This field may be auto-loaded 
from the EEPROM at power on or upon the assertion of PCI_RST#. A value of 
8086h is the default for this field upon power up if the EEPROM does not 
respond or is not programmed. 

Device ID 

This uniquely identifies the Ethernet controller. This field may be autoloaded 
from the EEPROM at power on or upon the assertion of RST#. The default value 
for this field is used upon power up if the EEPROM does not respond or is not 
programmed.

Command Reg. The layout is listed in 

. Shaded bits are not used by this implementation 

and are hard wired to 0b.

Status Register  The layout is listed in 

. Shaded bits are not used by this implementation 

and are hard wired to 0b.

Revision

Sequential stepping number starting with 00h for the A0 revision of the Ethernet 
controller. Refer to the PCI/PCI-X Family of Gigabit Ethernet Controllers 
Specification Update for the latest stepping information.

Class Code 

The class code, 020000h identifies the Ethernet controller as an Ethernet adapter.

1Ch

Base Address 3 (unused)

20h

Base Address 4 (unused)

2h4

Base Address 5 (unused)

28h

Cardbus CIS Pointer (not used)

2Ch

Subsystem ID

Subsystem Vendor ID

30h

Expansion ROM Base Address

34h

Reserved

Cap_Ptr

38h

Reserved

3Ch

Max_Latency 

(00h)

Min_Grant 

(FFh)

Interrupt Pin

(01h)

Interrupt Line

a.

Refer to 

.