82551QM Datasheet, PDF (67/120 Pages) Intel Corporation – Fast Ethernet Multifunction PCI/CardBus Controller

Networking Silicon — 82551QM
Figure 21. Modem PCI Configuration Registers
Reserved
38h
Max_Lat
Min_Gnt
Modem Power Management Capabilities
Modem Interrupt
Next Item Ptr
Capability ID
3Ch
DCh
Reserved
Modem Data
Modem Power Management CSR
E0h
The modem configuration registers define the resources required by the modem function. It is
meaningful in a multifunction card design only. Some of the modem configuration registers are a
reflection of their matched Ethernet registers. The registers’ values are pre-defined by hardware,
initialized by the EEPROM, or configurable through software. The shaded fields are described in
detail in the following subsections.
9.2.1
Modem Configuration ID Register
The Modem Configuration ID field is a Dword register composed of the Device ID and Vendor ID.
It is a read only register and its value is loaded from the EEPROM.
9.2.2
Modem Command Register
The Modem Command field is a 16-bit word register and provides basic control over the modem’s
ability to respond to PCI/CardBus accesses. The Command register’s structure is shown in Table
23.
Table 23. Power Management Control and Status Register
Bits Default Read/Write
Description
15:10
9
8
7
6
5
4
3
2
1
0
000000b
0b
0b
0b
0b
0b
0b
0b
0b
0b
0b
Read Only
Read Only
Read/Write
Read Only
Read/Write
Read Only
Read Only
Read Only
Read Only
Read/Write
Read/Write
Reserved. These bits are reserved and should be set to 000000b.
Fast Back-to-Back.
System Error Enable.
Wait Cycle Enable.
Parity Error Enable.
VGA (define).
Memory Write and Invalidate.
Special Cycle.
Master Enable.
Memory Access Enable.
I/O Access Enable.
Datasheet
61