
PC Card Controller Programming Model
100
September 2005
SCPS110
4.42 Power Management Capabilities Register
The power management capabilities register contains information on the capabilities of the PC Card function
related to power management. The CardBus bridge function supports D0, D1, D2, and D3 power states.
Default register value is FE12h for operation in accordance with PCI Bus Power Management Interface
Specification revision 1.1. See Table 419 for a complete description of the register contents.
PCI register offset:
A2h (Function 0)
Register type:
Read-only, Read/Write
Default value:
FE12h
BIT NUMBER
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESET STATE
1
0
1
0
1
0
Table 419. Power Management Capabilities Register Description
BIT
SIGNAL
TYPE
FUNCTION
This 5-bit field indicates the power states from which the controller function can assert PME. A 0b for any
bit indicates that the function cannot assert the PME signal while in that power state. These 5 bits return
11111b when read. Each of these bits is described below:
15
PME support
RW
Bit 15 defaults to a 1b indicating the PME signal can be asserted from the D3cold state. This bit is
read/write because wake-up support from D3cold is contingent on the system providing an auxiliary power
source to the VCC terminals. If the system designer chooses not to provide an auxiliary power source to
the VCC terminals for D3cold wake-up support, then BIOS must write a 0b to this bit.
1411
R
Bit 14 contains the value 1b to indicate that the PME signal can be asserted from the D3hot state.
Bit 13 contains the value 1b to indicate that the PME signal can be asserted from the D2 state.
Bit 12 contains the value 1b to indicate that the PME signal can be asserted from the D1 state.
Bit 11 contains the value 1b to indicate that the PME signal can be asserted from the D0 state.
10
D2_Support
R
This bit returns a 1b when read, indicating that the function supports the D2 device power state.
9
D1_Support
R
This bit returns a 1b when read, indicating that the function supports the D1 device power state.
86
RSVD
R
Reserved. These bits return 000b when read.
5
DSI
R
Device-specific initialization. This bit returns 0b when read.
4
AUX_PWR
R
Auxiliary power source. This bit is meaningful only if bit 15 (D3cold supporting PME) is set. When this bit
is set, it indicates that support for PME in D3cold requires auxiliary power supplied by the system by way
of a proprietary delivery vehicle.
A 0b in this bit field indicates that the function supplies its own auxiliary power source.
If the function does not support PME while in the D3cold state (bit 15 = 0), then this field must always return
0b.
3
PMECLK
R
When this bit is 1b, it indicates that the function relies on the presence of the PCI clock for PME operation.
When this bit is 0b, it indicates that no PCI clock is required for the function to generate PME.
Functions that do not support PME generation in any state must return 0b for this bit.
20
Version
R
Power management version.
If bit 4 (PCI_PM_VERSION_CTRL) in the device control register (PCI offset 92h, see Section 4.38) is 0b,
this field returns 010b indicating PCI Bus Power Management Interface Specification (Revision 1.1)
compatibility.
If bit 4 (PCI_PM_VERSION_CTRL) in the device control register is 1b, this field returns 011b indicating
PCI Bus Power Management Interface Specification (Revision 1.2) compatibility.
This bit is cleared only by the assertion of GRST.