Datasheet

PCI Express Non-Transparent Bridge
Intel
®
Xeon
®
Processor C5500/C3500 Series
Datasheet, Volume 1 February 2010
290 Order Number: 323103-001
3.21.1.13 SBDF: Secondary Bus, Device and Function
This register contains the Bus, Device and Function for the secondary side of the NTB
when PPD.Port Definition is configured as NTB/NTB Section 3.19.3.23, “PPD: PCIE Port
Definition” .
Note: The region between the two NTBs is in no mans land and does not matter what value
BDF is set to, but the same value must be programmed in both NTBs on each side of
the link. The default values have been set to unique bus values midway in the bus
region to simplify validation. The SBDF has been made programmable in case end user
wishes to move the SBDF for specific validation needs.
Note: This register is only valid when configured as NTB/NTB. This register has no meaning
when configured as NTB/RP or RP.
3.21.1.14 CBDF: Captured Bus, Device and Function
This register contains the Bus, Device and Function for the secondary side of the NTB
when PPD.Port Definition is configured as NTB/RP Section 3.19.3.23, “PPD: PCIE Port
Definition” .
Note: When configured as a NTB/RP, the NTB must capture the Bus and Device Numbers
supplied with all Type 0 Configuration Write Requests completed by the NTB and supply
these numbers in the Bus and Device Number fields of the Requester ID for all
Requests initiated by the NTB. The Bus Number and Device Number may be changed at
run time, and so it is necessary to re-capture this information with each and every
Configuration Write Request.
Note: When configured as a NTB/RP, if NTB must generate a Completion prior to the initial
device Configuration Write Request, 0’s must be entered into the Bus Number and
Device Number fields
Note: This register is only valid when configured as NTB/RP. This register has no meaning
when configured as NTB/NTB or RP.
Register:SBDF
Bar:PB01BASE, SB01BASE
Offset:5Ch
Bit Attr Default Description
15:8 RW 7Fh
Secondary Bus
Value to be used for the Bus number for ID-based routing.
Hardware will leave the default value of 7Fh when this port is USD
Hardware will increment the default value to 80h when this port is DSD
7:3 RW 00000b
Secondary Device
Value to be used for the Device number for ID-based routing.
2:0 RW 000b
Secondary Function
Value to be used for the Function number for ID-based routing.