User guide

• Error Location Capture cannot be used.
• The function Error Detector Pattern tracks the Pattern Generator Pattern is
disabled. This function is not re-enabled when the BRM is terminated.
• BRM does not work above 11.5 Gb/s when the CDR is enabled.
BRM indicators:
• The mode is indicated in the status panel and in the BER Bar.
• The mode is indicated in all screen dumps and log files.
• The Measurement User Interface shows when this mode is used.
Sampling Point Setup - Procedures
In most cases you will set up the sampling point automatically. Even if you wish
to make some manual adjustments, it is recommended to start with automatically
aligning the sampling point.
N O T E
Before adjusting the sampling point, make sure the pattern synchronization mode
is set up properly. See “Pattern Synchronization - Procedures” on page 216 for
details.
How to Set the Optimum Sampling Point Automatically
1
Click Sampling Point Setup menu item from the ED Setup submenu.
2
Select an appropriate BER threshold from the BER Threshold list.
3
Press Auto Align to automatically set the optimum sampling point.
You can stop the search for the optimum sampling point at any time by pressing
Cancel.
How to Adjust the Data Input Delay
1
Click Sampling Point Setup menu item from the ED Setup submenu.
2
Select the Avg. 0/1 Threshold checkbox to use a good start point on the vertical
voltage axis.
3
Click Data Center to move the sampling point horizontally towards the center
of the eye at the selected voltage. You may click Cancel at any time.
4
Now you can use the numeric keypad or front panel knob to manually adjust
the value in the Data Delay field.
5 Setting up the Error Detector
196 Agilent J-BERT N4903B High-Performance Serial BERT