Intel BX80633I74960X PCI Express* Related Register Structures in the Processor, PCI Express* Port

Interfaces—Processor
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* Port

The PCI Express* interface on the processor is a single, 16-lane (x16) port that can also be configured at narrower widths. The PCI Express* port is being designed to be compliant with the PCI Express Base Specification, Revision 3.0.

PCI Express* Lanes Connection

The following figure demonstrates the PCIe* lane mapping.

Desktop 4th Generation Intel® Core™ Processor Family, Desktop Intel® Pentium® Processor Family, and Desktop Intel® Celeron® Processor Family

December 2013	Datasheet – Volume 1 of 2
Order No.: 328897-004	25