Specification Sheet
PCI Express* Controller (x8) Registers
452 Datasheet, Volume 2 of 2
13.41 Slot Capabilities (SLOTCAP)—Offset B4h
PCI Express Slot related registers allow for the support of Hot Plug.
Access Method
Default: 40000h
Type: CFG
(Size: 32 bits)
Offset: [B:0, D:1, F:1] + B4h
3
1
2
8
2
4
2
0
1
6
1
2
8
4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PSN
NCCS
EIP
SPLS
SPLV
HPC
HPS
PIP
AIP
MSP
PCP
ABP
Bit
Range
Default &
Access
Field Name (ID): Description
31:19
0h
RW_O
PSN: Physical Slot Number: Indicates the physical slot number attached to this Port.
BIOS Requirement: This field should be initialized by BIOS to a value that assigns a
slot number that is globally unique within the chassis.
18
1h
RO
NCCS: No Command Completed Support: When set to 1b, this bit indicates that this
slot does not generate software notification when an issued command is completed by
the Hot-Plug Controller. This bit is only permitted to be set to 1b if the hotplug capable
port is able to accept writes to all fields of the Slot Control register without delay
between successive writes.
17
0h
RO
EIP: Reserved for Electromechanical Interlock Present: When set to 1b, this bit
indicates that an Electromechanical Interlock is implemented on the chassis for this
slot.
16:15
0h
RW_O
SPLS: Slot Power Limit Scale: Specifies the scale used for the Slot Power Limit Value.
00: 1.0x
01: 0.1x
10: 0.01x
11: 0.001x
If this field is written, the link sends a Set_Slot_Power_Limit message.
14:7
0h
RW_O
SPLV: Slot Power Limit Value: In combination with the Slot Power Limit Scale value,
specifies the upper limit on power supplied by slot. Power limit (in Watts) is calculated
by multiplying the value in this field by the value in the Slot Power Limit Scale field.
If this field is written, the link sends a Set_Slot_Power_Limit message.
6
0h
RO
HPC: Reserved for Hot-plug Capable: When set to 1b, this bit indicates that this slot is
capable of supporting hot-plug operations.
5
0h
RO
HPS: Reserved for Hot-plug Surprise: When set to 1b, this bit indicates that an
adapter present in this slot might be removed from the system without any prior
notification. This is a form factor specific capability. this bit is an indication to the
operating system to allow for such removal without impacting continued software
operation.
4
0h
RO
PIP: Reserved for Power Indicator Present: When set to 1b, this bit indicates that a
Power Indicator is electrically controlled by the chassis for this slot.
3
0h
RO
AIP: Reserved for Attention Indicator Present: When set to 1b, this bit indicates that
an Attention Indicator is electrically controlled by the chassis.