82551IT Datasheet, PDF (56/102 Pages) Intel Corporation – Fast Ethernet PCI Controller

82551IT — Networking Silicon
Table 17. Power Management Capability Register
Bits Default Read/Write
Description
20
0b (PCI)
19
0b
18:16 010b
Read Only
Read Only
Read Only
Reserved PCI.
PME# Clock. The 82551IT does not require a clock to generate a
power management event.
Version. A value of 010b indicates that the 82551IT complies with of
the PCI Power Management Specification, Revision 2.2.
7.1.20
Power Management Control/Status Register (PMCSR)
The Power Management Control/Status is a word register. It is used to determine and change the
current power state of the 82551IT and control the power management interrupts in a standard
manner.
Table 18. Power Management Control and Status Register
Bits Default Read/Write
Description
15
0b
14:13 0b
12:9 0b
8
0b
7:5
0b
4
0b
3:2
0b
1:0
0b
Read/Clear
Read Only
Read Only
Read Clear
Read Only
Read Only
Read Only
Read/Write
PME# Status. This bit is set upon a wake-up event. It is independent
of the state of the PME# Enable bit. If 1b is written to this bit, the bit will
be cleared. It also de-asserts the PME# signal and clears the PME#
status bit in the Power Management Driver Register. When the PME#
signal is enabled, the PME# signal reflects the state of the PME status
bit.
Data Scale. This field indicates the data register scaling factor. It
equals 1b for registers zero through eight and 0b for registers 9
through 15.
Data Select. This field is used to select which data is reported through
the Data register and Data Scale field.
PME Enable. This bit enables the 82551IT to assert PME#.
Reserved. These bits are reserved and should be set to 0b.
Dynamic Data. The 82551IT does not support the ability to monitor
the power consumption dynamically.
Reserved. These bits are reserved and should be set to 0b.
Power State. This 2-bit field is used to determine the current power
state of the 82551IT and to set the 82551IT into a new power state.
The definition of the field values is as follows.
00 - D0
01 - D1
10 - D2
11 - D3
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Datasheet