Agilent Technologies J-BERT N4903, User Manual

Page: 133 / 434

you can click Cancel . The status message bar will indicate if this function
is unsuccessful.
The following settings may affect the result of the auto align function:
•
Data Inverted
• BER Threshold
T I P
Alternatively, you can also press the Auto Align button on the front panel.
Sync Now
Click this button to manually start a pattern synchronization. See “What
Type of Synchronization Should You Use?” on page 141 for information
on when you should use this function.
Note that this button is not available in bit recovery mode.
0/1 THReshold Center
Starts an auto-search function that sets the 0/1 threshold to the
optimum point of the incoming data eye on the vertical voltage axis
without changing the data input delay. This function can be used for
determining the optimum 0/1 threshold for asymmetric data eyes, or
for patterns with an unequal mark density.
The status message bar will indicate if this function is unsuccessful. This
function clears the
Avg. 0/1 Threshold checkbox.
N O T E
This function uses the alignment BER Threshold to determine the top and bottom
eye edges.
Data Center
This button starts an auto-search function that aligns the data signal
with the clock signal so that the error detector samples at the optimum
point of the data eye in the time axis. This automatically compensates
for delays in the clock/data paths, preventing unnecessary errors. The
0/1 decision threshold is not changed. The status message bar will
indicate if this function is unsuccessful.
N O T E
Ensure that the received clock frequency is stable before using Data Center.
Setting up the Error Detector
4
Agilent J-BERT N4903 High-Performance Serial BERT 133