Datasheet, Volume 2
191
Processor Configuration Registers
2.12.9
DMIVC1RCTL—DMI VC1 Resource Control Register
This register controls the resources associated with PCI Express Virtual Channel 1.
B/D/F/Type:
0/0/0/DMIBAR
Address Offset:
20–23h
Reset Value:
01000000h
Access:
RO, RW
Size:
32 bits
BIOS Optimal Default
00000h
Bit
Attr
Reset
Value
RST/
PWR
Description
31
RW
0b
Uncore
Virtual Channel 1 Enable (VC1E)
0 = Disabled.
1 = Enabled. See exceptions below.
Software must use the VC Negotiation Pending bit to check
whether the VC negotiation is complete. When VC Negotiation
Pending bit is cleared, a 1 read from this VC Enable bit indicates
that the VC is enabled (Flow Control Initialization is completed for
the PCI Express port). A 0 read from this bit indicates that the
Virtual Channel is currently disabled.
BIOS Requirement:
1.
To enable a Virtual Channel, the VC Enable bits for that Virtual
Channel must be set in both Components on a Link.
2.
To disable a Virtual Channel, the VC Enable bits for that
Virtual Channel must be cleared in both Components on a
Link.
3.
Software must ensure that no traffic is using a Virtual Channel
at the time it is disabled.
4.
Software must fully disable a Virtual Channel in both
Components on a Link before re-enabling the Virtual Channel.
30:27
RO
0h
Reserved
26:24
RW
001b
Uncore
Virtual Channel 1 ID (VC1ID)
Assigns a VC ID to the VC resource. Assigned value must be non-
zero. This field can not be modified when the VC is already
enabled.
23:20
RO
0h
Reserved
19:17
RW
000b
Uncore
Port Arbitration Select (PAS)
Configures the VC resource to provide a particular Port Arbitration
service. Valid value for this field is a number corresponding to one
of the asserted bits in the Port Arbitration Capability field of the VC
resource.
16:8
RO
0h
Reserved
7
RO
0b
Uncore
Traffic Class m / Virtual Channel 1 (TCMVC1M)
6:1
RW
00h
Uncore
Traffic Class / Virtual Channel 1 Map (TCVC1M)
This field indicates the TCs (Traffic Classes) that are mapped to the
VC resource. Bit locations within this field correspond to TC values.
For example, when bit 6 is set in this field, TC6 is mapped to this
VC resource. When more than one bit in this field is set, it indicates
that multiple TCs are mapped to the VC resource. To remove one
or more TCs from the TC/VC Map of an enabled VC, software must
ensure that no new or outstanding transactions with the TC labels
are targeted at the given Link.
BIOS Requirement:
Program this field with the value 010001b,
which maps TC1 and TC5 to VC1.
0
RO
0b
Uncore
Traffic Class 0 / Virtual Channel 1 Map (TC0VC1M)
Traffic Class 0 is always routed to VC0.