Datasheet

Processor Integrated I/O (IIO) Configuration Registers
68 Datasheet, Volume 2
3.3.4.23 SLTCAP—PCI Express* Slot Capabilities Register
The Slot Capabilities register identifies the PCI Express specific slot capabilities. These
registers must be ignored by software on the DMI links.
Note: Hot-plug for PCIe is not supported on Desktop, Platforms.
Register: SLTCAP
Device: 0 (DMI), 3, 5 (PCIe)
Function: 0
Offset: A4h
Bit Attr Default Description
31:19 RWO 0h
Physical Slot Number
This field indicates the physical slot number of the slot connected to the PCI
Express* port and is initialized by BIOS.
18 RO 0h
Command Complete Not Capable
Integrated I/O is capable of command complete interrupt.
17 RWO 0h
Electromechanical Interlock Present
When set to 1, this bit indicates that an Electromechanical Interlock is
implemented on the chassis for this slot and that lock is controlled by Bit 11 in
Slot Control register.
BIOS Note: This capability is not set if the Electromechanical Interlock control
is connected to main slot power control.
16:15 RWO 0h
Slot Power Limit Scale
This field specifies the scale used for the Slot Power Limit Value and is
initialized by BIOS. IIO uses this field when it sends a Set_Slot_Power_Limit
message on PCI Express.
Range of Values:
00 = 1.0x
01 = 0.1x
10 = 0.01x
11 = 0.001x
14:7 RWO 00h
Slot Power Limit Value
This field specifies the upper limit on power supplied by slot in conjunction
with the Slot Power Limit Scale value defined previously
Power limit (in Watts) = SPLS x SPLV.
This field is initialized by BIOS. IIO uses this field when it sends a
Set_Slot_Power_Limit message on PCI Express.
Design Note: Integrated I/O can choose to send the Set_Slot_Power_Limit
message on the link at first link up condition without regards to whether this
register and the Slot Power Limit Scale register are programmed yet by BIOS.
Integrated I/O must then be designed to discard a received
Set_Slot_Power_Limit message without an error.
6:5 RV 0h
Reserved - Hot-Plug is not supported.
4RWO 0h
Power Indicator Present
When set to 1, this bit indicates that a Power Indicator is implemented for this
slot and is electrically controlled by the chassis.
3RWO 0h
Attention Indicator Present
When set to 1, this bit indicates that an Attention Indicator is implemented for
this slot and is electrically controlled by the chassis
2RWO 0h
MRL Sensor Present
When set to 1, this bit indicates that an MRL Sensor is implemented on the
chassis for this slot.
1RWO 0h
Power Controller Present
When set to 1, this bit indicates that a software controllable power controller is
implemented on the chassis for this slot.
0RV 0h
Reserved - Hot-Plug is not supported.