Slot Capabilities Register
| Bit | Description | Attributes | Implementation |
|---|---|---|---|
| 0 | Attention Button Present. When set, this bit indicates that an Attention Button for this slot is electrically controlled by the chassis | HwInit | RW from APB |
| 1 | Power Controller Present. When set, this bit indicates that a software programmable Power Controller is implemented for this slot/adapter (depending on form factor). | HwInit | RW from APB |
| 2 | Allows the Port and system software to detect the MRL being opened | HwInit | RW from APB |
| 3 | Prevents removal of adapter from slot | HwInit | RW from APB |
| 4 | Allows user to request hot-plug operations | HwInit | RW from APB |
| 5 | Allows user to request hot-plug operations | HwInit | RW from APB |
| 6 | Provides visual identification of slots | HwInit | RW from APB |
| 14:7 |
Slot Power Limit Value. In combination with the Slot Power Limit Scale
value, specifies the upper limit on power supplied by the slot (see Section 6.9) or
by other means to the adapter. Power limit (in Watts) is calculated by multiplying
the value in this field by the value in the Slot Power Limit Scale field except when
the Slot Power Limit Scale field equals 00b (1.0x) and Slot Power Limit Value
exceeds EFh, the following alternative encodings are used:
F0h: 250 W Slot Power Limit
F1h: 275 W Slot Power Limit
F2h: 300 W Slot Power Limit
F3h to FFh: Reserved for Slot Power Limit values above 300 W
This register must be implemented if the Slot Implemented bit is
Set. Writes to this register also cause the Port to send the
Set_Slot_Power_Limit Message. The default value prior to
hardware/firmware initialization is 0000 0000b.
|
HwInit | In Root Port mode, write into this register causes Controller to transmit a Set_Slot_Power_Limit Message. |
| 16:15 |
Slot Power Limit Scale. Specifies the scale used for the Slot Power Limit
Value (see Section 6.9). Range of Values:
00b: 1.0x
01b: 0.1x
10b: 0.01x
11b: 0.001x
This register must be implemented if the Slot Implemented bit is Set. Writes
to this register also cause the Port to send the Set_Slot_Power_Limit Message. The
default value prior to hardware/firmware initialization is 00b.
|
HwInit | In Root Port mode, write into this register causes Controller to transmit a Set_Slot_Power_Limit Message. |
| 17 | Electromechanical Interlock Present. When set, this bit indicates that an Electromechanical Interlock is implemented on the chassis for this slot. | HwInit | RW from APB |
| 18 |
No Command Completed Support. When set, 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 if the hot-plug capable
Port is
able to accept writes to all fields of the Slot Control register
without delay between successive writes.
|
HwInit | RW from APB |
| 31:19 | Physical Slot Number. This field indicates the physical slot number attached to this Port. This field must be hardware initialized to a value that assigns a slot number that is unique within the chassis, regardless of the form factor associated with the slot. This field must be initialized to zero for Ports connected to devices that are either integrated on the system board or integrated within the same silicon as the Switch device or Root Port. | HwInit | RW from APB |