Intel 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - DATASHEET VOLUME 2 01-2011 Datasheet page 202

B/D/F/Type:
Address Offset:
Reset Value:
Access:
Size:
BIOS Optimal Default
Bit
6
5
4
3:0
202
0/0/0/DMIBAR
98–99h
0002h
RWS, RWS-V
16 bits
0h
Reset RST/
Attr
Value PWR
Powerg
ood
RWS 0b
Powerg
RWS 0b
ood
Powerg
RWS 0b
ood
Powerg
RWS 2h
ood
Processor Configuration Registers
Description
Selectable De-emphasis (selectabledeemphasis)
When the Link is operating at 5 GT/s speed, this bit selects the
level of de-emphasis. Encodings:
1 = -3.5 dB
0 = -6 dB
When the Link is operating at 2.5 GT/s speed, the setting of this bit
has no effect. Components that support only the 2.5 GT/s speed
are permitted to hardwire this bit to 0b.
NOTE: For DMI, this bit has no effect in functional mode as DMI is
half-swing and will use -3.5 dB when de-emphasis is enabled.
Hardware Autonomous Speed Disable (HASD)
1 = Disables hardware from changing the link speed for reasons
other than attempting to correct unreliable link operation by
reducing link speed.
0 = Enable
Enter Compliance (EC)
Software is permitted to force a link to enter Compliance mode at
the speed indicated in the Target Link Speed field by setting this bit
to 1 in both components on a link and then initiating a hot reset on
the link.
Target Link Speed (TLS)
For Downstream ports, this field sets an upper limit on link
operational speed by restricting the values advertised by the
upstream component in its training sequences.
0001b = 2.5 Gb/s Target Link Speed
0010b = 5 Gb/s Target Link Speed
All other encodings are reserved.
If a value is written to this field that does not correspond to a
speed included in the Supported Link Speeds field, the result is
undefined.
The Reset Value of this field is the highest link speed supported by
the component (as reported in the Supported Link Speeds field of
the Link Capabilities Register) unless the corresponding platform /
form factor requires a different Reset Value.
For both Upstream and Downstream ports, this field is used to set
the target compliance mode speed when software is using the
Enter Compliance bit to force a link into compliance mode.
Datasheet, Volume 2