Altera JNEye User Manual
Page 173
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![background image](/files/763732/content/doc173.png)
Figure 3-22: Phase Noise of Reference Clock and Its Transitions through PLL and CDR
At the output of the PCI-Express 8G receiver’s 1-Tap DFE, the following figures show that the DFE has
further opened the eye diagram with a total jitter of 1 UI (at BER < 10
-12
, with ideal clock and sinusoidal
jitter from the transmitter reference clock) and 0.53 UI (with CDR recovered clock) and eye diagram
opening height of 0 mV (with ideal clock) and 66 mV (with recovered clock). The BER bathtub curve and
contour show good behavior and successfully meet the PCI-Express 8GT RX requirements (TJ < 0.7 UI
and eye diagram height > 25 mV; refer to PCI-Express Base Specification 4.3).
3-22
Analysis
UG-1146
2015.05.04
Altera Corporation
Tutorial: PCI Express 8GT
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