Intel E3-1105C AV8062701048800 Scheda Tecnica

Intel

®

 Xeon

®

 and Intel

®

 Core™ Processors For Communications Infrastructure

May 2012

Datasheet - Volume 1 of 2

Document Number: 327405

-

001

35

The controllers in Port 1 cannot be used to function with the controller in Port 2. 

Therefore, the x16 lanes of Port 1 must not be combined with the x4 lanes of Port 2.

The following details apply to the 3 controllers in Port 1, as Port 2 cannot be bifurcated. 

The configuration of the PCIe* bus is statically determined by the pre-boot software 

prior to initialization. The pre-boot software determines the configuration by looking at 

the two configuration pins, CFG[6:5], that determine whether the additional 2 

controllers of the 16 lanes need to be enabled or not. These strap values are read upon 

power up and the pre-boot software enables the appropriate number of controllers in 

use as follows:

No strapping is required to enable the additional four lanes (lanes [16-19]) in any of 
the permissible modes as it has a single dedicated controller.

The CFG[6:5] inputs have a default value of [1:1] if they are not terminated on the 

board. By default, a single x16 controller is enabled. When a logic 0 is required on the 

strap, it is recommended that they be pulled down to ground with a 1 K Ohm resistor

If the x16 controller is enabled by the hardware strapping and a x8 device is plugged 

in, the controller automatically operates in the x8 mode. The same is true for any 

controller that is connected to a device operating at narrower lane widths.

Hot plug is not supported on these PCIe* interfaces. If a device is not present at power 

up, it is not detected when it is plugged in after power up. Also, the strap values are 

read upon power up and the pre-boot software enables the appropriate controller 

based on the value read on CFG[6:5]. Hence, if a device of lower lane width than the 

width of the controller that is enabled is plugged in before power up, then it is 

automatically detected. But if a device with higher lane width is plugged in, the device 

is not detected. The same is true for the number of controllers enabled. If a single 

controller is enabled at power up, then a single device of any width equal to or lower 

than the width of the controller is detected.

For example, if upon power up, the value on CFG [6:5] is [1:1], then the 1x16 

controller is enabled. A single device of width x16 will be detected upon power up. But 

if two devices of any lower width are plugged in; only the device connected to Device 1, 

Function 0 will be detected.

00

1x8 +2x4

01

Reserved

2x8

1x16