PCI Configuration Registers
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 280
PME Status 15
RW2C
0x0
This bit is set when the device asserts the WAKE signal
independent of the PME enable bit. Writing 1 this bit will clear it
and cause the device to stop asserting WAKE
Data Scale
14:13
RO
0x1
Indicates the scaling factor that is used when interpreting the value
of the data register (offset 7 in PM capability space). The device
hardwires this value to 1 to indicate a scale of 1x
Data Select 12:9
RW
0x0
Indicates which data is to be reported via the Data register (offset
7 in PM capability space)
PME Enable 8
RW
0x1
Enables the device to generate PME when this bit is set to 1.
When 0, PME generation is disabled
Reserved
7:4
RO
0x00
–
No Soft
Reset
3
RO
0x1
No_Soft_Reset
When set (1), this bit indicates that devices transitioning from
D3hot to D0 because of PowerState commands do not perform an
internal reset. Configuration Context is preserved. Upon transition
from the D3hot to the D0 Initialized state, no additional operating
system intervention is required to preserve Configuration Context
beyond writing the PowerState bits.
When clear (0), devices do perform an internal reset upon
transitioning from D3hot to D0 via software control of the
PowerState bits. Configuration Context is lost when performing the
soft reset. Upon transition from the D3hot to the D0 state, full
reinitialization sequence is needed to return the device to D0
Initialized.
Regardless of this bit, devices that transition from D3hot to D0 by
a system or bus segment reset will return to the device state D0
Uninitialized with only PME context preserved if PME is supported
and enabled.
Reserved
2
RO
0x0
–
Power State 1:0
RW
0x0
Indicates the current power state of the device when read.
When written, it sets the device into the specified power state
00: D0 – Select D0
01: D1 – Select D1
10: D2 – Select D2
11: D3-Hot – Select D3
These bits may be used by the system to set the power state. The
register is implemented as two banks of two bits each. Can be
written from both configuration space and from the PCI register
space as the PM_STATE bits. When written from the PCI bus, only
values of 0 and 3 are accepted. This is the register returned on
reads of this register from configuration space. The second bank
catches all writes values. The value of the second register is
returned when the PM_STATE bits are read from register space.
The idea of these registers is to a) Provide compatible operation
to 5701 b) Allow implementation of other power states though
firmware.
Name
Bits
Access
Default
Value
Description