Datasheet

Processor Configuration Registers
236 Datasheet, Volume 2
2.12.27 LCTL2—Link Control 2 Register
B/D/F/Type: 0/0/0/DMIBAR
Address Offset: 98–99h
Reset Value: 0002h
Access: RWS, RWS-V
Size: 16 bits
Bit Access
Reset
Value
RST/
PWR
Description
15:12 RWS 0000b Powergood
Compliance De-emphasis (ComplianceDeemphasis)
For 8 GT/s Data Rate: This field sets the Transmitter Preset
level in Polling.Compliance state if the entry occurred due to
the Enter Compliance bit being 1b. The encodings are defined
in PCIe Specification, Section 4.2.3.2.
For 5 GT/s Data Rate: This bit filed sets the de-emphasis level
in Polling.Compliance state if the entry occurred due to the
Enter Compliance bit being 1b.
0001b = -3.5 dB
0000b = -6 dB
When the Link is operating at 2.5 GT/s, the setting of this bit
has no effect. Components that support only 2.5 GT/s speed
are permitted to hardwire this bit to 0b.
For a Multi-Function device associated with an Upstream Port,
the bit in Function 0 is of type RWS, and only Function 0
controls the component's Link behavior. In all other Functions
of that device, this bit is of type RsvdP.
The Reset Value of this bit is 0b.
This bit is intended for debug, compliance testing purposes.
System firmware and software is allowed to modify this bit only
during debug or compliance testing.
11 RWS 0b Powergood
Compliance SOS (compsos)
When set to 1b, the LTSSM is required to send SKP Ordered
Sets periodically in between the (modified) compliance
patterns. For a Multi-Function device associated with an
Upstream Port, the bit in Function 0 is of type RWS, and only
Function 0 controls the component's Link behavior. In all other
Functions of that device, this bit is of type RsvdP. The Reset
Value of this bit is 0b. Components that support only the
2.5 GT/s speed are permitted to hardwire this field to 0b.
10 RWS 0b Powergood
Enter Modified Compliance (entermodcompliance)
When this bit is set to 1b, the device transmits modified
compliance pattern if the LTSSM enters Polling.Compliance
state.
Components that support only the 2.5 GT/s speed are
permitted to hardwire this bit to 0b.
Reset Value of this field is 0b.