Intel PCI User Manual

112

This word is loaded into the Circuit Control Register (CIRC) for setting PCI-X driver strength. See 

 and 

 for suggested values.

Note: PCI-X is not applicable to the 82540EP/EM, 82541xx, and 82547GI/EI.

If the signature bits are valid and Power Management is not disabled, the value in this field is used 

in the PCI Power Management Data Register when the Data_Select field of the Power 

Management Control/Status Register (PMCSR) is set to 0 or 4. This indicates the power usage and 
heat dissipation of the networking function (including the Ethernet controller and any other devices 

managed by the Ethernet controller) in tenths of a watt. For example:

If word22h = 290E, POWER CONSUMPTION (in 1/10W, hex), then:

bits 15:8 = 29h Power in D0a, 29h = 4.1W

bits 7:0 = 0Eh Power in D3h, 0Eh = 1.4W

If the signature bits are valid and Power Management is not disabled, the value in this field is used 
in the PCI Power Management Data Register when the Data_Select field of the Power 

Management Control/Status Register (PMCSR) is set to 3 or 7. This indicates the power usage and 

heat dissipation of the networking function (including the Ethernet controller and any other devices 
managed by the Ethernet controller) in tenths of a watt as described in 

.

Words 23h through 2Eh of the EEPROM are reserved areas for the 82541ER.

Words 23h through 2Fh of the EEPROM are reserved areas for the 82544GC/EI.