Datasheet

Datasheet, Volume 2 223
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 Access
Reset
Value
RST/
PWR
Description
31 RW 0b Uncore
Virtual Channel 1 Enable (VC1E)
0 = Virtual Channel is disabled.
1 = Virtual Channel is 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 (RSVD)
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 cannot be modified when the VC is already
enabled.
23:20 RO 0h Reserved (RSVD)
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 (RSVD)
7RO 0bUncoreTraffic Class m / Virtual Channel 1 (TCMVC1M)
6:1 RW 00h Uncore
Traffic Class / Virtual Channel 1 Map (TCVC1M)
This 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. In
order 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.
0RO 0bUncore
Traffic Class 0 / Virtual Channel 1 Map (TC0VC1M)
Traffic Class 0 is always routed to VC0.