82801DB Datasheet, PDF (478/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

AC ’97 Audio Controller Registers (D31:F5)
14.1.23
PCS—Power Management Control and Status Register
(Audio—D31:F5)
Address Offset:
Default Value:
Lockable:
54h
0000h
No
Attribute:
Size:
Power Well:
R/W, R/WC
16 bits
Resume
Bit
Description
PME Status (PMES) — RW/C.
15 ^{0 = Software clears this bit by writing a 1 to it.}
1 = This bit is set when the AC ’97 controller would normally assert the PME# signal independent of
the state of the PME_En bit. This bit resides in the resume well.
14:9 Reserved — RO.
PME Enable (PMEE) — R/W.
8 ^{0 = Disable.}
1 = Enable. When set, and if corresponding PMES is also set, the AC'97 controller sets the
AC97_STS bit in the GPE0_STS register
7:2 Reserved — RO.
Power State — R/W. This field is used both to determine the current power state of the AC ’97 control-
ler and to set a new power state. The values are:
00 = D0 state
01 = not supported
1:0 10 = not supported
11 = D3_HOT state
When in the D3_HOT state, the AC ’97 controller’s configuration space is available, but the I/O and
memory spaces are not. Additionally, interrupts are blocked.
If software attempts to write a value of 10b or 01b in to this field, the write operation must complete
normally; however, the data is discarded and no state change occurs.
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Intel^® 82801DB ICH4 Datasheet