82551QM Datasheet, PDF (70/120 Pages) Intel Corporation – Fast Ethernet Multifunction PCI/CardBus Controller

82551QM — Networking Silicon
9.2.14
9.2.15
9.2.16
Modem Power Management Control/Status Register
The Modem Power Management Control/Status Register is a word register. It is used to manage the
modem’s power management state. It also enables and monitors power management events. The
Modem Power Management Control/Status Register structure is identical to register E0h in
Function 0, LAN (Ethernet) function.
Modem Data Register
The Modem Data register has similar functionality to register E2h in Function 0, LAN (Ethernet).
The register at location E2h reports power consumption of the modem function. The value of
power consumption and power dissipation are loaded from the EEPROM.
Table 26. Ethernet Data Register
Data Select Data Scale
Data Reported
0-3
4-7
8 - 15
2
D0 to D3 Power Consumption (loaded from
EEPROM)
2
D0 to D3 Power Dissipated (loaded from
EEPROM)
0
Reserved (00h)
Modem Support in PCI Mode
The 82551QM supports a modem interface in PCI mode. The Modem Enable (MDM) bit in the
EEPROM can be activated in PCI systems without the loss of BootROM support. In addition,
BootROM support has been simplified. The 82551QM supports the co-existence of a BootRom
Flash device and a modem device. This is done by setting the MDM bit and clearing the Boot
Disable (BD) bit in the EEPROM. With this configuration, both modem functionality and the
BootRom BAR are active. The selection between the two functions is done through Boot Enable
bit (the least significant bit of the BootRom BAR in the LAN PCI Configuration space). The
82551QM will not support a LAN/modem design if additional companion ASICs are operating on
the Flash/modem interface. This limitation does not affect companion ASICs that reside on the
SMB interface of the 82551QM.
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Datasheet