User guide

For more information on input timing adjustment of N4876A, refer to the section
“N4876A System Setup Adjustment” on page 490.
Clock Multiplier Window
The Clock Multiplier enables BER measurements using the forwarded clock as
sampling clock for Serial BERT.
The Clock Multiplier window contains the following elements:
You can use the Track PG Clock Frequency check box to toggle between frequency
and multiplier provided by Pattern Generator and the Input frequency and multiplier
provided in the Clock Multiplier window.
If the Track PG Clock Frequency check box is not selected, then you can provide
the values of the clock multiplier. Following are the valid values:
• Multiplier: 1 Freq Range : 1GHz to to 13.5GHz
• Multiplier: 2 Freq Range : 1GHz to to 6.75GHz
If the Track PG Clock Frequency check box is selected, then the firmware will
control both frequency as well as the multiplier value. In this case the de-emphasis
box (Clock Multiplier) is clocked by a Half Rate Clock (DataRate/2) provided by the
Pattern Generator. So the two parameters of the Pattern Generator have now
influence on the clock multiplier’s frequency and multiplier. First it’s the data rate
of the instrument (can be changed from the Pattern Generator – Bit Rate Setup
dialog) and the Half Rate Clock check box (can be changed from the Pattern
Generator Clock/Trigger Output).
2 Setting up External Instrument(s)
54 Agilent J-BERT N4903B High-Performance Serial BERT
Track PG Clock Frequency