User guide

Instead of UI (one Unit Interval is equal to one system clock period), the relative
time can also be specified in seconds.
• The Voltage is the decision threshold voltage at this measurement point. The
voltages of the measurement points can be set as absolute voltages, as offset
voltages, or as percentages. This is done on the Parameters page of the
Properties dialog.
By default, the six measurement points are symmetrically placed, as illustrated in
the figure below:
These settings can be changed, and up to 32 measurement points can be defined.
N O T E
Critical areas at the error detector are generally close to ±0.5 UI.
Fast Eye Mask - Procedures
This section shows how to set up and perform a Fast Eye Mask measurement. As
an example we measure the eye of a shielded cable.
This requires the following steps:
• Preparing the Fast Eye Mask Measurement. (See “How to Prepare the Fast Eye
Mask Measurement” on page 310 ).
• Executing the Fast Eye Mask Measurement. (See “How to Execute the Fast
Eye Mask Measurement” on page 310 ).
Advanced Analysis 6
Agilent J-BERT N4903B High-Performance Serial BERT 309