Datasheet

Processor Configuration Registers
206 Datasheet, Volume 2
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".
B/D/F/Type: 0/6/0/MMR
Address Offset: 110–113h
Reset Value: 00000001h
Access: RO
Size: 32 bits
BIOS Optimal Default 00h
Bit Access
Reset
Value
RST/
PWR
Description