PCI Express* Registers (D1:F0)
Bit
Access &
Default
Description
10
RO
0b
Power Controller Control (PCC): If a Power Controller is
implemented, this field when written sets the power state of the slot
per the defined encodings. Reads of this field must reflect the value
from the latest write, even if the corresponding hotplug command is
not complete, unless software issues a write without waiting for the
previous command to complete in which case the read value is
undefined.
Depending on the form factor, the power is turned on/off either to the
slot or within the adapter. Note that in some cases the power
controller may autonomously remove slot power or not respond to a
power-up request based on a detected fault condition, independent of
the Power Controller Control setting.
The defined encodings are:
0 = Power On
1 = Power Off
If the Power Controller Implemented field in the Slot Capabilities
register is set to 0b, then writes to this field have no effect and the
read value of this field is undefined.
9:8
RO
Power Indicator Control (PIC): If a Power Indicator is
01b
implemented, writes to this field set the Power Indicator to the
written state. Reads of this field must reflect the value from the latest
write, even if the corresponding hot-plug command is not complete,
unless software issues a write without waiting for the previous
command to complete in which case the read value is undefined.
00 = Reserved
01 = On
10 = Blink
11 = Off
7:6
RO
11b
Attention Indicator Control (AIC): If an Attention Indicator is
implemented, writes to this field set the Attention Indicator to the
written state.
Reads of this field must reflect the value from the latest write, even if
the corresponding hot-plug command is not complete, unless
software issues a write without waiting for the previous command to
complete in which case the read value is undefined. If the indicator is
electrically controlled by chassis, the indicator is controlled directly by
the downstream port through implementation specific mechanisms.
00 = Reserved
01 = On
10 = Blink
11 = Off
Datasheet
199
INTEL [ INTEL ]
