UG526

Detailed Description

9. PCI Express Endpoint Connectivity

The 1-lane PCIe edge connector performs data transfers at the rate of 2.5 GT/s for a Gen1 application. The Spartan-6 FPGA GTP MGT is used for the multi-gigabit per second serial interface.

The SP605 board trace impedance on the PCIe lane supports Gen1 applications. The SP605 supports Gen1 x1.

Table 1-11:

PCIe Edge Connector Connections

P4 PCIe Edge Connector

U1 FPGA Pin Schematic Net Name

Pin Number Pin Name

–

–

B10

A10

J7

C7

D7

A6

B6

PCIE_RX0_N

PCIE_RX0_P

PCIE_TX0_N

(1)

PCIE_TX0_P

(1)

PCIE_CLK_QO_N

(2)

PCIE_CLK_QO_P

(2)

PCIE_250M_N

(3)(6)

PCIE_250M_P

(3)(6)

PCIE_PERST_B_LS

B15

B14

A17

A16

A14

A13

U48.17

(4)

U48.18

(4)

A11

PETn0

PETp0

PERn0

PERp0

REFCLK-

REFCLK+

NQ

Q

PERST

(5)

Notes:

1. Each of the TX0_N/P signals has a 0.1 µF series capacitor.

2. PCIE_CLK_QO_N/P is the PC motherboard 100MHZ REFCLK.

3. Each of the PCIE_250M_N/P signals has a 0.1 µF series capacitor.

4. U48 is an ICS874001 clock multiplier device (U48.17/18 are not P4 pins).

5. The PERST signal from pin P4.A11 is isolated by a series resistor and then level-shifted by U52 before making the FPGA pin U1.J7 connection.

6. PCIE_250M_N/P signals can be a frequency other than 250 MHz, depending on the settings selected by resistor population for U48 ICS874001. The default setting is 125 MHz.

The PCIe interface obtains its power from the DC power supply provided with the SP605 or through the 12V ATX power supply connector. The PCIe edge connector is not used for any power connections.

The board can be powered by one of two 12V sources; J18, a 6-pin (2x3) Mini-Fit-type connector and J27, a 4-pin (inline) ATX disk drive type connector.

The 6-pin Mini-Fit-type connector provides 60W (12V @ 5A) from the AC power adapter provided with the board while the 4-pin ATX disk drive type connector is provided for users who want to power their board while it is installed inside a PC chassis.

For applications requiring additional power, such as the use of expansion cards drawing significant power, a larger AC adapter might be required. If a different AC adapter is used, its load regulation should be better than ±10%.

SP605 power slide switch SW2 turns the board on and off by controlling the 12V supply to the board.

Caution!

Caution! Never apply power to the power brick 6-pin Mini-Fit type connector (J18) and the 4-pin ATX disk drive type connector (J27) at the same time as this will result in damage to the board. Never connect an auxiliary PCIe 6-pin power connector to J18 6-pin Mini-Fit type connector on the SP605 board as this could result in damage to the PCIe motherboard and/or

SP605 Hardware User Guide

UG526 (v1.8) September 24, 2012 www.xilinx.com

31

Chapter 1: SP605 Evaluation Board

SP605 board. The 6-pin Mini-Fit type connector is marked with a no PCIe power label to warn users of the potential hazard.

References

See the Spartan-6 FPGA GTP Transceivers User Guide for more information.

[Ref 6]

Also, see the following websites for more information about the Spartan-6 FPGA Integrated

Endpoint Block for PCI Express:

• Product information, http://www.xilinx.com/products/ipcenter/S6_PCI_Express_Block.htm

• IP data sheets, http://www.xilinx.com/support/documentation/ipbusinterfaceio_pci-express.htm#131486

In addition, see the PCI Express specifications for more information.

[Ref 16]

32

www.xilinx.com

SP605 Hardware User Guide

UG526 (v1.8) September 24, 2012