Xilinx ML628, Getting Started Manual

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22 www.xilinx.com ML628 IBERT Getting Started Guide
UG806 (v1.0) May 20, 2011
Running the GTX IBERT Demonstration
The SuperClock-2 module provides LVDS clock outputs for the GTX and GTH transceiver
reference clocks in the IBERT demonstrations.
Figure 1-3, page 9 shows the locations of the
differential clock SMA connectors on the clock module which can be connected to the
reference clock cables. The four SMA pairs labeled CLKOUT provide LVDS clock outputs
from the Si5368 clock multiplier/jitter attenuator device on the clock module. The SMA
pair labeled Si570_CLK provides LVPECL clock output from the Si570 programmable
oscillator on the clock module. For the GTH IBERT demonstration, the output clock
frequencies are preset to 174.690 MHz. For more information regarding the SuperClock-2
module, refer to
UG770 , HW-CLK-101-SCLK2 SuperClock-2 Module User Guide .
Attach the GTX Quad Connector
Attach the Samtec BullsEye connector to GTX Quad 100 ( Figure 1-24 ), aligning the two
indexing pins on the bottom of the connector with the guide holes on the board. Hold the
connector flush with the board and fasten it by tightening the two captive screws.
GTX Transceiver Clock Connections
Refer to Figure 1-22, page 21 to identify the P and N coax cables that are connected to the
two reference clock inputs (CLK0 and CLK1). Connect these cables to the SuperClock-2
Module as follows:
• CLK0_P coax cable
→
SMA connector J5 (CLKOUT1_P) on the SuperClock-2 Module
• CLK0_N coax cable
→
SMA connector J6 (CLKOUT1_N) on the SuperClock-2 Module
• CLK1_P coax cable
→
SMA connector J7 (CLKOUT2_P) on the SuperClock-2 Module
• CLK1_N coax cable
→
SMA connector J8 (CLKOUT2_N) on the SuperClock-2 Module
Note:
Any one of the five differential outputs from the SuperClock-2 Module can be used to source
the GTX reference clock. CLKOUT1_P , CLKOUT1_N, CLKOUT2_P, and CLKOUT2_N are used here
as an example.
GTX TX/RX Loopback Connections
Refer to Figure 1-22, page 21 to identify the P and N coax cables that are connected to the
four receivers (RX0, RX1, RX2 and RX3) and the four transmitters (TX0, TX1, TX2 and TX3).
Use eight SMA female-to-female (F-F) adapters (
Figure 1-25 ), to connect the transmit and
receive cables as shown in Figure 1-26 and detailed below:
• TX0_P
→
SMA F-F Adapter
→
RX0_P
• TX0_N
→
SMA F-F Adapter
→
RX0_N
• TX1_P
→
SMA F-F Adapter
→
RX1_P
X-Ref Target - Figure 1-24
Figure 1-24: BullsEye Connector Attached to Quad 100
UG 8 06_c1_24_041411