Intel G640T CM8062301002204 User Manual

Datasheet, Volume 2

183

31:24

RO

00h

Uncore

23

RO

0h

22:16

RO

00h

Uncore

Reserved for Maximum Time Slots (MTS) 

15

RO

0b

Uncore

Reject Snoop Transactions (RSNPT)
0 = Transactions with or without the No Snoop bit set within the 

TLP header are allowed on this VC.

1 = Any transaction for which the No Snoop attribute is applicable 

but is not Set within the TLP Header will be rejected as an 

Unsupported Request

14:8

RO

0h

7:0

RO

01h

Uncore

Port Arbitration Capability (PAC)
Indicates types of Port Arbitration supported by the VC resource. 

This field is valid for all Switch Ports, Root Ports that support peer- 

to-peer traffic, and RCRBs, but not for PCI Express Endpoint 

devices or Root Ports that do not support peer-to-peer traffic.
Each bit location within this field corresponds to a Port Arbitration 

Capability defined below. When more than one bit in this field is 

set, it indicates that the VC resource can be configured to provide 

different arbitration services.
Software selects among these capabilities by writing to the Port 

Arbitration Select field (see below).
Defined bit positions are:
Bit 0

Non-configurable hardware-fixed arbitration scheme, 

such as, Round Robin (RR)

Bit 1

Weighted Round Robin (WRR) arbitration with 32 phases

Bit 2

WRR arbitration with 64 phases

Bit 3

WRR arbitration with 128 phases

Bit 4

Time-based WRR with 128 phases

Bit 5

WRR arbitration with 256 phases

Bits 6–7 Reserved
Processor only supported arbitration indicates "Non-configurable 

hardware-fixed arbitration scheme".