Intel G640T CM8062301002204 User Manual

Datasheet, Volume 2

179

This is for PCI Express Slot related registers.

15:9

RO

0h

8

RO

0b

Uncore

Reserved for Data Link Layer State Changed (DLLSC)
This bit is set when the value reported in the Data Link Layer Link 

Active field of the Link Status register is changed. In response to a 

Data Link Layer State Changed event, software must read the Data 

Link Layer Link Active field of the Link Status register to determine 

if the link is active before initiating configuration cycles to the hot 

plugged device.

7

RO

0b

Uncore

Reserved for Electromechanical Interlock Status (EIS)
If an Electromechanical Interlock is implemented, this bit indicates 

the current status of the Electromechanical Interlock.
0 = Electromechanical Interlock Disengaged

1 = Electromechanical Interlock Engaged

6

RO-V

0b

Uncore

Presence Detect State (PDS)
In band presence detect state:
0 = Slot Empty

1 = Card present in slot
This bit indicates the presence of an adapter in the slot, reflected 

by the logical "OR" of the Physical Layer in-band presence detect 

mechanism and, if present, any out-of-band presence detect 

mechanism defined for the slot's corresponding form factor. Note 

that the in-band presence detect mechanism requires that power 

be applied to an adapter for its presence to be detected.
Consequently, form factors that require a power controller for hot-

plug must implement a physical pin presence detect mechanism.
0 = Slot Empty

1 = Card Present in slot
This register must be implemented on all Downstream Ports that 

implement slots. For Downstream Ports not connected to slots 

(where the Slot Implemented bit of the PCI Express Capabilities 

Register is 0b), this bit must return 1b.

5

RO

0b

Uncore

Reserved for MRL Sensor State (MSS)
This register reports the status of the MRL sensor if it is 

implemented.
0 = MRL Closed

1 = MRL Open

4

RO

0b

Uncore

Reserved for Command Completed (CC)
If Command Completed notification is supported (as indicated by 

No Command Completed Support field of Slot Capabilities 

Register), this bit is set when a hot-plug command has completed 

and the Hot-Plug Controller is ready to accept a subsequent 

command. The Command Completed status bit is set as an 

indication to host software that the Hot-Plug Controller has 

processed the previous command and is ready to receive the next 

command; it provides no guarantee that the action corresponding 

to the command is complete.
If Command Completed notification is not supported, this bit must 

be hardwired to 0b.