Intel C2550 FH8065401488912 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

September 2014

Datasheet, Vol. 2 of 3

Order Number: 330061-002US

233

The PCI Express interface consists of up to 16 physical lanes and up to four Root Port 

controllers, depending on product SKU. For a given SKU, the number of available lanes 

and controllers may be further reduced and configured using soft straps and bifurcation 

settings. 

 shows the supported configurations assuming all 16 lanes and 4 

controllers are available.

• Product SKU dictates the maximum number of supported physical lanes and Root 

Port Controllers. Reference to 

• Bifurcation may organize the remaining available lanes and controllers.
• During Link training, lane reversal may occur on a per-controller basis.

Interfacing with a x8 PCIe device is supported with bifurcation to either:

• One controller as x16.
• Two controllers, each up to x8 wide.
• Three controllers, one up to x8 wide and two up to x4 wide.

With degraded operation:

• A 16-lane link connected to a x8, x2 or x1 PCIe device.
• An 8-lane link connected to a x2 or x1 PCIe device.
• A 4-lane link connected to a x2 or x1 PCIe device.

Since the smallest bifurcation granularity is x4 (for 4 controllers), attached PCIe x2 or 

x1 devices each require a four-lane controller for connection.

One

x16, x8, x4, x2, x1

For the single controller configuration

Two

x8, x4, x2, x1 and
x8, x4, x2, x1

Independent selection per controller

Three

x8, x4, x2, x1 and

x4, x2, x1 and

x4, x2, x1

Independent selection per controller

One wide channel and two narrow channels

All Four

x4, x2, x1 and

x4, x2, x1 and

x4, x2, x1 and

x4, x2, x1

Independent selection per controller