Interfaces
Intel
®
Core
TM
i7-620LE/UE, i7-610E, i5-520E and Intel
®
Celeron
®
Processor P4500, P4505 Series
Datasheet Addendum
April 2010
20
Document Number: 323178-002
2.2.2
PCI Express Port Bifurcation
When bifurcated, the wires which had previously been assigned to lanes 15:8 of the
single x16 primary port (Port 0) are reassigned to lanes 7:0 of the x8 secondary port
(Port 1). This assignment applies whether the lane numbering is reversed or not. The
controls for the secondary port (Port 1) and the associated virtual PCI-to-PCI bridge
can be found in PCI Device 6.
When the primary port is not bifurcated, Device 6 is hidden from the discovery
mechanism used in PCI enumeration, such that configuration of the device is neither
possible nor necessary.
Figure 4.
PCI Express* Related Register Structures in the
Intel
®
Core
TM
i7-620LE/UE, i7-610E, i5-520E and Intel
®
Celeron
®
Processor
P4500, P4505 Series
PCI-PCI Bridge
representing root
PCI Express port
(Device 1)
PCI-PCI Bridge
representing root
PCI Express port
(Device 6)
PCI Compatible
Host Bridge Device
(Device 0)
PCI Express
Device
PCI Express
Device
Port 0
Port 1
DMI