Processor Configuration Registers
B/D/F/Type:
Address Offset:
Reset Value:
Access:
0/1/0–2/PCI
D0–D1h
0003h
RWS, RWS-V
16 bits
Size:
Reset
Value
RST/
PWR
Bit
Access
Description
Selectable De-emphasis (selectabledeemphasis)
When the Link is operating at 5 GT/s speed, selects the level of
de-emphasis. Encodings:
1 = -3.5 dB
0 = -6 dB
6
RWS
RO
0b
0h
Powergood
Reset Value is implementation specific, unless a specific value
is required for a selected form factor or platform.
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.
5:4
Reserved (RSVD)
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.
Defined encodings are:
0001b = 2.5 Gb/s Target Link Speed
0010b = 5 Gb/s Target Link Speed
0011b = 8 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.
3:0
RWS
3h
Powergood
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.
130
Datasheet, Volume 2