Intel PCI User Manual

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Software Developer’s Manual
105
EEPROM Interface
5.6.7
Initialization Control Word 1 (Word 0Ah)
The first word read by the Ethernet controller contains initialization values that:
Sets defaults for some internal registers
Enables/disables specific features
Determines which PCI configuration space values are loaded from the EEPROM
Table 5-5. Initialization Control Word 1 (Word 0Ah)
Bit
Name
Description
15:14
Signature
The Signature field represents a signature of 01b (default), indicating to the 
Ethernet controller that there is a valid EEPROM present. 
If the Signature field is not 01b, the other bits in this word are ignored, no 
further EEPROM read is performed, and default values are used for the 
configuration space IDs.
13
64/32 BAR
When set to 0b (default), enables 64-bit memory mapping.
When set to 1b, disables 64-bit memory mapping
Note: Set to 1b for the 82540EP/EM.
12
IPS0
When set to 0b (default), does not invert the Power State Output bit 0 
(CTRL_EXT[14]). 
When set to 1b, inverts the Power State Output invert bit 0 
(CTRL_EXT[14]).
Note: Reserved bit for the 82541xx and 82547GI/EI (set to 0b).
11
FRCSPD
Force Speed bit in the Device Control register (CTRL[11]).
When set to 0b (default), does not force speed.
When set to 1b, forces speed (default for the 82540EP/EM).
For 10/100/1000 Mb/s systems using TBI mode (82544GC/EI)/internal 
SerDes (82546GB/EB and 82545GM/EM)
a
, set this bit to 0b.
Note: Reserved bit for the 82541xx and 82547GI/EI (set to 0b).
10
FD
Full Duplex (mapped to CTRL[0] and TXCW[5]).
When set to 1b (default), enables full duplex (TBI mode/internal SerDes 
only).
When set to 0b, disables full duplex (TBI mode only/internal SerDes).
Note: Reserved bit for the 82541PI/GI/EI and 82547GI/EI (set to 1b).
Note: Reserved bit for the 82541ER (set to 0b).
9
LRST
Link Reset (mapped to CTRL[3]). 
When set to 0b, enables Auto-Negotiation at power up or when asserting 
RST# without driver intervention. 
When set to 1b, disables Auto-Negotiation at power up or when asserting 
RST# without driver intervention.
Note: Reserved bit for the 82541xx and 82547GI/EI (set to 0b).
8
IPS1
When set to 0b (default), does not invert the Power State Output bit 1 
(CTRL_EXT[16]). 
When set to 1b, inverts the Power State Output invert bit 1 
(CTRL_EXT[16]).
Note: Reserved bit for the 82541xx and 82547GI/EI (set to 0b).