Specification Sheet

DMIBAR Registers
146 Datasheet, Volume 2 of 2
6.9 DMI VC1 Resource Control (DMIVC1RCTL)—Offset
20h
Controls the resources associated with PCI Express Virtual Channel 1.
Access Method
Default: 1000100h
Type: MEM
(Size: 32 bits)
Offset: [B:0, D:0, F:0] + 20h
3
1
2
8
2
4
2
0
1
6
1
2
8 4 0
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0
VC1E
RSVD
VC1ID
RSVD
PAS
RSVD
FC_FSM_STATE
TCMVC1M
TCVC1M
TC0VC1M
Bit
Range
Default &
Access
Field Name (ID): Description
31
0h
RW
VC1E: Virtual Channel 1 Enable:
0: Virtual Channel is disabled.
1: Virtual Channel is enabled. See exceptions below.
Software should 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 should be
set in both Components on a Link.
2. To disable a Virtual Channel, the VC Enable bits for that Virtual Channel should be
cleared in both Components on a Link.
3. Software should ensure that no traffic is using a Virtual Channel at the time it is
disabled.
4. Software should fully disable a Virtual Channel in both Components on a Link
before re-enabling the Virtual Channel.
30:27
0h
RO
Reserved (RSVD): Reserved.
26:24
1h
RW
VC1ID: Virtual Channel 1 ID: Assigns a VC ID to the VC resource. Assigned value
should be non-zero. This field can not be modified when the VC is already enabled.
23:20
0h
RO
Reserved (RSVD): Reserved.
19:17
0h
RW
PAS: Port Arbitration Select: 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.
16:13
0h
RO
Reserved (RSVD): Reserved.
12:8
1h
ROV
FC_FSM_STATE: This register is for Save Restore to restore the FC fsm