Altera JNEye User Manual
Page 170
Figure 3-19: Channel Output Hybrid Eye Diagrams and BER Analysis
The CTLE is a PCI-Express 8GT CTLE behavior model output stage. The JNEye's link optimization
algorithm has identified the optimal gain setting at 10 dB level. Similar to the TX output case, when the
receiver CDR is enabled or included in the simulation, two sets of CTLE outputs are shown. The first set
of outputs is with the ideal clock and the second one is with the CDR recovered clock. The total jitter is 1
UI (at BER < 10
-12
, with ideal clock) or 0.54 UI (with CDR recovered clock). The eye diagram opening
height is 0 mV (with ideal clock) and 41 mV (with recovered clock). The eye diagram opening is marginal
to PCI-Express 8GT requirements. Therefore, further equalization of the signal with DFE is needed.
UG-1146
2015.05.04
Analysis
3-19
Tutorial: PCI Express 8GT
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