82551QM Datasheet, PDF (69/120 Pages) Intel Corporation – Fast Ethernet Multifunction PCI/CardBus Controller

Networking Silicon — 82551QM
9.2.7
9.2.8
Modem Memory Base Address Register
The Modem Memory BAR is a Dword register that specifies the memory base address for
accessing the 82551QM’s modem port. The required memory space is 4 KB. The memory space is
used for both control registers and CIS mapping.
Modem CardBus CIS Pointer
The CIS pointer is a Dword, hard-coded, read only register. The CIS pointer indicates whether or
not the CIS structure is located in the memory address space. The physical location of the CIS
structure is in the serial EEPROM. The EEPROM format is described in Section 5.7, “Serial
EEPROM Interface”.
Bits
31:4
3:0
R/W Default
R
0010h
R
2h
Description
Modem CIS Pointer (above the control registers)
CIS in the Memory Base Address Register
9.2.9
Modem Subsystem Vendor ID Register
The Modem Subsystem Vendor ID is a 16-bit read only register. Its value is loaded from the
EEPROM and is a reflection of register 2Ch in Function 0, LAN (Ethernet) function.
9.2.10
Modem Subsystem ID Register
The Modem Subsystem ID is a 16-bit, read only register. Its value is loaded from the EEPROM and
is a reflection of register 2Eh in Function 0, LAN (Ethernet) function.
9.2.11
Modem Capabilities Pointer
The Modem Capability Pointer is a hard-coded, byte register that contains the value DCh. It
provides an offset within the Configuration Space for the location of the power management
registers.
9.2.12
Modem Interrupt Register
The Modem Interrupt register specifies whether or not the modem requires an interrupt. This
register is hard-coded identically to register 3Ch in Function 0, LAN (Ethernet). It indicates that
the modem requires interrupt support.
Note: The modem and Ethernet functions share the same INTA# pin.
9.2.13
Modem Power Management Capabilities Register
The Modem Power Management Capabilities register is a Dword field that indicates if this
function has power management capability. It also identifies which power management capabilities
are supported. The 82551QM reports a value of FE31h if it is connected to an auxiliary power
source; and 7E21h, otherwise.
Datasheet
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