Datasheet

Datasheet, Volume 2 139
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Processor Integrated I/O (IIO) Configuration Registers
3.2.8.8 DMIVCPRCTL—DMI VCP Resource Control Register
Controls the resources associated with the DMI Private Channel (VCp).
DMIVCPRCTL
Bus: 0 Device: 0 Function: 0 MMIO BAR: DMIRCBAR
Offset: 2C
Bit Attr
Reset
Value
Description
31 RW-LB 0b
Virtual Channel Private Enable
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 RV 0h Reserved
26:24 RW-LB 010b
Virtual Channel Private ID
Assigns a VC ID to the VC resource. This field can not be modified when the VC is
already enabled. No private VCs are precluded by hardware and private VC
handling is implemented the same way as non-private VC handling.
23:8 RV 0h Reserved
7RO 0b
Traffic Class 7/ Virtual Channel 0 Map
Traffic Class 7 is always routed to VCm.
6:1 RW-LB 00h
Traffic Class / Virtual Channel private Map
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.
0RO 0b
Traffic Class 0 / Virtual Channel Private Map
Traffic Class 0 is always routed to VC0.