Table 4-9: Example Signal Paths; Table 4-10: Settings And Results - Xilinx RocketIO X User Manual

Simulation Transmitter Emphasis and Receiver Equalization Settings

Table 4-9: Example Signal Paths

Many different PCB materials and connectors are available in the market, and using
different PCB material or a different connector will definitely change these settings in
Table
optimum settings might be different depending on the trace width, PCB stack-up (layer
thicknesses), and so on. However, these numbers can be a good start. These numbers can
change depending upon semiconductor process corners, temperature, supply voltage, etc.
Note:
Therefore, Xilinx emphasizes that these numbers are only estimates (i.e., ballpark numbers);
hence, Xilinx is not responsible if these are not the optimum settings for a particular application.
More detailed descriptions of the transmit pre-emphasis and receive equalization are
given in this chapter, and users are encouraged to read those sections to understand the
pre-emphasis and equalization features before trying them out.

Table 4-10: Settings and Results

None
Parameter
10
TXDOWNLEVEL 1000
[3:0]
TXEMPHLEVEL 0000
[3:0]
RXFER[9:0] 1111110111 1111111111 1111111111 1111110111 1111111001 1111111001 1111110111
RXLOOPFILTER 01
[1:0]
RXLOOPFILTER 101
[1:0]
Notes:
1. The eye described here is the simulated eye after the equalizer.
2. Measured as a pk-pk differential RX voltage.
3. All other control signals are set to their default settings.
RocketIO™ X Transceiver User Guide
UG035 (v1.5) November 22, 2004
Trace
Long trace for 6.25 Gb/s
and 3.125 Gb/s
Medium trace for 6.25 Gb/s
and 3.125 Gb/s
Short trace for 6.25 Gb/s
and 3.125 Gb/s
Medium trace for 10 Gb/s
Short trace for 10 Gb/s
"None" trace for 10 Gb/s,
6.25 Gb/s, and 3.125 Gb/s
4-10. Even if the same PCB material and connector are used as described here, the
These numbers are based on simulation only, and not based on actual characterization.
None None Short
6 3 10
1000 1000 1000
0000 0000 0000
01 01 01
100 010 101
www.xilinx.com
1-800-255-7778
package -|- 3" FR4 -|- VHDM-HSD connector -|- 40" FR4
-|- VHDM-HSD connector -|- 3" FR4 -|- package
package -|- 3" FR4 -|- VHDM-HSD connector -|- 20" FR4
-|- VHDM-HSD connector -|- 3" FR4 -|- package
package -|- 3" FR4 -|- VHDM-HSD connector -|- 7" FR4
-|- VHDM-HSD connector -|- 3" FR4 -|- package
package -|- 3" FR4 -|- Gbx connector -|- 10" FR4 -|- Gbx
connector -|- 3" FR4 -|- package
package -|- 3" FR4 -|- Gbx connector -|- 2" FR4 -|- Gbx
connector -|- 3" FR4 -|- package
package -|- package
Short Short Medium
6 3 10
1000 1000 1000
0000 0000 0010
01 01 01
100 010 101
Signal Path
Medium Medium Long
6 3 6
1000 1000 1000
0100 0000 0100
1111111001 1111111001 1101100001 1111100001
01 01 01
100 010 100
R
Long
3
1000
0100
01
010
113