Intel G640T CM8062301002204 User Manual

192

Datasheet, Volume 2

This register controls the resources associated with PCI Express Virtual Channel 1.

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

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

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

7

RO

0b

Uncore

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.