Processor—Interfaces

Figure 3.

PCI Express* Related Register Structures in the Processor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI-PCI

 

 

 

 

 

 

 

 

 

 

 

Bridge

 

 

 

PCI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI

PEG0

 

representing

 

 

 

Compatible

 

 

 

 

Express*

 

root PCI

 

 

 

Host Bridge

 

 

 

 

 

 

 

 

 

 

 

 

 

Device

 

 

Express ports

 

 

 

Device

 

 

 

 

 

 

 

(Device 1 and

 

 

 

(Device 0)

 

 

 

 

 

 

 

Device 6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DMI

 

 

 

 

 

 

 

 

 

 

 

 

PCI Express* extends the configuration space to 4096 bytes per-device/function, as compared to 256 bytes allowed by the conventional PCI specification. PCI Express* configuration space is divided into a PCI-compatible region (that consists of the first 256 bytes of a logical device's configuration space) and an extended PCI Express* region (that consists of the remaining configuration space). The PCI-compatible region can be accessed using either the mechanisms defined in the PCI specification or using the enhanced PCI Express* configuration access mechanism described in the PCI Express* Enhanced Configuration Mechanism section.

The PCI Express* Host Bridge is required to translate the memory-mapped PCI Express* configuration space accesses from the host processor to PCI Express* configuration cycles. To maintain compatibility with PCI configuration addressing mechanisms, it is recommended that system software access the enhanced configuration space using 32-bit operations (32-bit aligned) only. See the PCI Express Base Specification for details of both the PCI-compatible and PCI Express* Enhanced configuration mechanisms and transaction rules.

PCI Express* Lanes Connection

The following figure demonstrates the PCIe* lane mapping.

Intel® Xeon® Processor E3-1200 v3 Product Family

 

Datasheet – Volume 1 of 2

June 2013

24

Order No.: 328907-001