7−13
7.19 Power Management Capabilities Register

The power management capabilities register indicates the capabilities of the PCI7x21/PCI7x11 controller related to

PCI power management. See Table 7−16 for a complete description of the register contents.

Bit 15 14 13 12 11 109876543210
Name Power management capabilities
Type RURRRRRRRRRRRRRRR
Default 0111111000000010
Register: Power management capabilities
Offset: 46h
Type: Read/Update, Read-only
Default: 7E02h

Table 7−16. Power Management Capabilities Register Description

BIT FIELD NAME TYPE DESCRIPTION
15 PME_D3COLD RU
PME support from D3cold. This bit can be set to 1 or cleared to 0 via bit 15 (PME_D3COLD) in the PCI
miscellaneous configuration register at offset F0h in the PCI configuration space (see Section 7.23).
The PCI miscellaneous configuration register is loaded from ROM. When this bit is set to 1, it indicates
that the PCI7x21/PCI7x11 controller is capable of generating a PME wake event from D3cold. This bit
state is dependent upon the PCI7x21/PCI7x11 VAUX implementation and may be configured by using
bit 15 (PME_D3COLD) in the PCI miscellaneous configuration register (see Section 7.23).
14−11 PME_SUPPORT R PME support. This 4-bit field indicates the power states from which the PCI7x21/PCI7x11 controller
may assert PME. This field returns a value of 1111b by default, indicating that PME may be asserted
from the D3hot, D2, D1, and D0 power states.
10 D2_SUPPORT R D2 support. Bit 10 is hardwired to 1, indicating that the PCI7x21/PCI7x11 controller supports the D2
power state.
9 D1_SUPPORT R D1 support. Bit 9 is hardwired to 1, indicating that the PCI7x21/PCI7x11 controller supports the D1
power state.
8−6 AUX_CURRENT R
Auxiliary current. This 3-bit field reports the 3.3-VAUX auxiliary current requirements. When bit 15
(PME_D3COLD) is cleared, this field returns 000b; otherwise, it returns 001b.
000b = Self-powered
001b = 55 mA (3.3-VAUX maximum current required)
5 DSI R Device-specific initialization. This bit returns 0 when read, indicating that the PCI7x21/PCI7x11
controller does not require special initialization beyond the standard PCI configuration header before
a generic class driver is able to use it.
4 RSVD R Reserved. Bit 4 returns 0 when read.
3 PME_CLK R PME clock. This bit returns 0 when read, indicating that no host bus clock is required for the
PCI7x21/PCI7x11 controller to generate PME.
2−0 PM_VERSION R Power-management version. This field returns 010b when read, indicating that the PCI7x21/PCI7x11
controller is compatible with the registers described in the PCI Bus Power Management Interface
Specification (Revision 1.1).