User guide

DUT Output Timing/Jitter - Procedures
This section shows how to set up and use the DUT Output Timing/Jitter
measurement. As an example, we measure the output timing and jitter behavior
of a shielded cable.
This requires the following steps:
• Preparing the measurement (see “How to Prepare the DUT Output Timing/
Jitter Measurement” on page 250)
• Executing the measurement (see “How to Execute the DUT Output Timing/
Jitter Measurement” on page 251)
• Optimizing the view of the results (see “How to Optimize the View of the
Results” on page 251)
How to Prepare the DUT Output Timing/Jitter Measurement
To use the DUT Output Timing/Jitter measurement to test a shielded cable:
1
Disable the pattern generator outputs by pressing the 0V (Disable) button in
the PG Setup -> Data Output screen.
2
Use a shielded cable to connect the pattern generator's Data Out port and the
error detector's Data In port.
3
Terminate all non-connected pattern generator output ports with 50 Ω.
4
Use a shielded cable to connect the pattern generator's Data Out port and the
error detector's Data In port.
5
Switch to the Pattern menu and press Pattern Select. Select an appropriate
pattern, for example a pure 2^15-1 PRBS, for both the pattern generator and
the error detector.
6
For the pattern generator setup you need to specify the logic levels and the bit
rate. Select LVPECL levels and Gb Ethernet (1.06250Gb/s) as clock speed. See
“Setting up the Pattern Generator - Concepts ” on page 121 for more
information.
7
Set up the error detector so that the input range and the termination matches
the pattern generator's levels:
– Select an Input Range from 1V to 3V
– Set the Data Termination to 1.3V
– Set the Clock Setup to Clock Data Recovery to get the error detector's
clock from the incoming data stream.
8
Enable the pattern generator outputs by pressing the 0V (Disable) button.
6 Advanced Analysis
250 Agilent J-BERT N4903B High-Performance Serial BERT