Advanced Eye Toolbar
Advanced Eye Analysis provides the ability to Measure TJ (Total Jitter), DJ (Deterministic Jitter) and RJ (Random Jitter) on patterns longer than PRBS16, such as PRBS31. The software also provides the ability to perform mask testing based on BER eye contours. Advanced Eye Analysis also allows you to perform the RJ, DJ, and TJ measurements directly from within FlexDCA without the use of the spreadsheet. Advanced eye measurements are located on the Adv Eye toolbar in Eye/Mask mode.
Advanced Eye (Adv Eye) Toolbar
Toolbar 1 of 2
Toolbar 2 of 2
Eye Mode's Advanced Eye measurements provide the ability to make the jitter and interference measurements listed on the toolbar. To perform these measurements on PAM4 signals, install the additional option 9FP (or 9TP) PAM-N Analysis software license. Since these measurements are made on an eye diagram, the pattern itself can be of any type or length, such as PRBS31. (Jitter Mode's measurements are limited to patterns up to PRBS16.) When performing a jitter measurement, you can specify a fixed value of RJ to use during jitter decomposition. The selected fixed RJ is applied to all advanced-eye jitter measurements: TJ, DJ, RJ, and Jn. When performing a interference measurement, you can specify a fixed value of RN to use during noise decomposition. The selected fixed RN is applied to all advanced-eye noise measurements: TI, DI, and RN.
All Advanced Eye measurements are compatible with both NRZ and PAM4 waveforms.
Advanced Eye measurements requires FlexDCA revision A.02.50 and above.
Eye Contour Lines
Advanced Eye includes the ability to draw eye contour lines on NRZ and PAM4 eye diagrams as shown in the picture below. Eye contours provide additional insights into the quality of an eye diagram. Contour lines are scaled to BER. They mark the border within an eye where a specific fixed Symbol Error Ratio (BER) occurs. The following picture shows two contour lines on Channel 1A. One line marks the 1.0 x 10−9 border and one line marks the 1.0 x 10−15 border. On Channel 2A, contour lines are placed on all three eyes of the PAM4 waveform. With eye contours, you can create the following items:
- Up to 16 groups of lines placed on any displayed eye diagram.
- Each group can contain up to eight individual contour lines.
- Multiple eye contour groups can be placed on the same eye.
- When applied to a PAM4 waveform, the group's lines are displayed within each of the three eye openings.
- An Eye Contours legend is displayed next to the waveform and identifies each contour line.
To create a group of eye contour lines
- Click the Add Eye Contour button on the Adv Eye tab to open the Eye Contour Group Setup dialog box. Or, click Measure > Eye/Mask > Adv Eye > Add Eye Contour.
- Select the source waveform and contour lines and then close the dialog.
To edit an existing eye contour group or to move it to a different waveform
- Click on the group in the Eye Contour table to select the group.
- Click Setup, which is located beneath the table to open the Eye Contour Group Setup dialog box. The dialog is populated with the current settings of the selected group. Make any needed changes, including source waveform, and close the dialog.
To Use a Fixed RJ or Fixed RN Value
Advanced eye leverages the DCA-X's ability to measure ultra-low levels of Random Jitter (RJ). This can be used to obtain fixed RJ values. The following steps fix RJ or RN to a value measured using a short pattern, which reduces the time required to make Advanced Eye measurements.
- Configure your test setup for the measurement. Select a pattern that is shorter than the pattern which will be used for the jitter or noise measurements.
- Place the 86100D in Jitter Mode and measure the RJ or RN.
- Place the 86100D in Eye/Mask Mode.
- Configure the pattern that will be used for making the measurements.
- In the Eye Mode's Adv Eye tab, click desired measurement button. For DJ (rms), TJ, RJ, or JN measurements, enter the fixed RJ that you made in step 2 above. For DI, TI, and RN measurements, enter the fixed RN.
- The measurement results are displayed in the measurement table.
You could also measure the RJ using a spectrum analyzer or some other method.
If you want to use a different RJ value for each waveform, separately measure each waveform or use the Advanced Eye Analysis application described in the next section.
Advanced Eye Analysis Application
The Advanced Eye Analysis application is run from the menu by clicking Apps > Automated Test Apps > Advanced Eye Analysis (401). This application does not require the use of a spreadsheet. It provides the following benefits:
- Guided procedure for obtaining a fixed RJ value using Jitter Mode and then using this value in Eye Mode's Advanced Eye toolbar measurements. The pattern length used for measuring the fixed RJ can be different from the pattern length used for the Eye Mode toolbar measurements. (Requires Option 200, Enhanced Jitter Analysis.)
- Ability to concurrently measure each lane of a multi-lane device while using a different fixed RJ value for each lane.
- Comprehensive report of the measurement results which can be printed and saved to a file.
Legacy Advanced Eye Analysis Spreadsheet Application
The Advanced Eye Analysis spreadsheet application is a Microsoft Office Excel 2003/Excel 2007 based workbook which runs on a PC and controls the 86100D. Normally, you will want to use the FlexDCA's Advanced Eye toolbar measurements or the Advanced Eye Analysis application as described above. However, if you want to perform amplitude measurments on patterns longer than 216, you must use this spreadsheet application.
The spreadsheet controls the instrument via LAN or GPIB communication. An option 401 license allows you to download the spreadsheet from Keysight.com and install run it on a PC or the 86100D. Either setup requires that you also purchase and install Microsoft Excel.