F-tile Architecture and PMA and FEC Direct PHY IP User Guide

ID 683872
Date 1/25/2023
Public

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8.2.6. Running Eye Viewer Tests

The Transceiver Toolkit supports internal eye measurements for Intel® Agilex™ F-Tile devices. The Eye Viewer section in every RX Channel tab under the Channel Parameters pane allows you to set up and run eye measurement tests.

  1. Select either Eye Width or Eye Height or both that you want to measure.
  2. Set Bit Error Rate to measure Eye Width and Bit Error Rate to measure Eye Height as shown in the following figure. Valid bit error rate range is from 1.0E-1 to 1.0E-12. The default bit error rate for NRZ is 1.0E-12, and for PAM4 is 1.0E-4.
    Figure 130. Setting the BER and Eye Measurement Options
  3. Specify the file path to store the results in CSV format.
  4. Click Start Eye Viewer. Make sure the RX channel is receiving data before starting eye measurement.
When measurement completes, the eye height and eye width results are shown in the following figures. For FGT NRZ signals, the Eye Center-to-top (Middle) and Eye Center-to-bottom (Middle) values are with reference to the center of the eye. Measurement from eye center to the top of the eye is a positive value. Measurement from the eye center to the bottom of the eye is a negative value. The Middle Eye Height is calculated by Eye Center-to-top (Middle) minus Eye Center-to-bottom (Middle). Eye width is reported in units of UI and seconds. For PAM4 signals, eye height of three eyes are shown. The Eye Center-to-top and Eye Center-to-bottom values of the top, middle and bottom eyes are referenced to the center of the middle eye. Measurement above center of the middle eye is a positive value; and measurement below is a negative value. The Eye Height is calculated by Eye Center-to-top minus Eye Center-to-bottom. A negative Eye Height value means the eye is closed. Only the worst eye width of the three eyes is shown.
Figure 131. FGT NRZ Eye Height and Eye Width Results
Figure 132. FGT PAM4 Eye Height and Eye Width Results