Intel PCI User Manual

106

If the signature bits (15:14) and bit 1 (Load Subsystem IDs) of word 0Ah are valid, this word is 
read in to initialize the Subsystem ID.

If the signature bits (15:14) and bit 1 (Load Subsystem IDs) of word 0Ah are valid, this word is 
read in to initialize the Subsystem Vendor ID.

7

Internal VREG Power 
Down Control

82541xx and 82547GI/EI Only
This bit is used to define the usage of the internal 1.2 V dc and 1.8 V dc 
regulators to supply power.
0b = Yes (default).
1b = No (external regulators used).
Note: Reserved bit for all other Ethernet controllers.

6:5

Reserved

Reserved for future use. Set these bits to 0b.

4

Reserved

Reserved for copper PHY. Set this bit to 0b.

3

Power Management

When set to 1b (default), enables full support for power management.
When set to 0b, the Power Management Registers set is read only. The 
Ethernet controller does not execute a hardware transition to D3.
Note: Reserved bit for the 82541PI/GI/EI and 82547GI/EI (set to 1b).
Note: Reserved bit for the 82541ER (set to 0b).

2

PME  Clock

When set to 0b (default), indicates that the PCICLK is not required for 
PME# output.
When set to 1b, indicates that the PCICLK is required for PME# output.
Note: Reserved bit for the 82541xx and 82547GI/EI (set to 0b).

1

Load Subsystem IDs

When set to 1b (default), indicates that the Ethernet controller is to load its 
PCI Subsystem ID and Subsystem Vendor ID from the EEPROM (words 
0Bh, 0Ch).
When set to 0b, indicates that the Ethernet controller is to load the default 
PCI Subsystem ID and Subsystem Vendor ID.

0

Load Vendor/Device 
IDs

When set to 0b (default), indicates that the Ethernet controller is to load the 
default values for PCI Vendor and Device IDs.
When set to 1b (default for the 82541xx and 82547GI/EI only), indicates 
that the Ethernet controller is to load its PCI Vendor and Device IDs from 
the EEPROM (words 0Dh, 0Eh).

a.

Not applicable to the 82541xx, 82547GI/EI or 82540EP/EM.