User guide

data rate / Acquisition Depth
For example: If you have a data rate of 2.5 GHz and an Acquisition Depth of
128 Kbit, the frequency resolution is 19.0735 kHz.
The relations are illustrated in the following figure:
N O T E
A high Acquisition Depth requires a high degree of computational effort and hence
time.
•
Sample Point Offset
By default, the sampling point for the measurement is positioned 0.5 clock
periods or UI ahead of the present analyzer sampling point.
If the sampling point is set in the middle of the eye, this corresponds to the
transition point of the incoming signal. If you have set the sampling delay
manually, this is the time offset from that point.
This option allows you to fine-tune the sampling point. The unit is UI (unit
intervals). This makes the setting independent of the present clock frequency.
Set the FFT window for the FFT Calculation. The following windows are provided:
• Uniform
• Hanning (sometimes also called Hann)
• Hamming
• Blackman
The "uniform" window is no window at all. This setting supplies the original error
record to the FFT.
6 Advanced Analysis
354 Agilent J-BERT N4903B High-Performance Serial BERT