62 Keysight M8040A High-Performance BERT Getting Started Guide
3 Using the M8040A High-Performance BERT
11 Click on Data Out corresponding to the M8045A (M1) and select the
line coding PAM-4.
Fi
gure 26 Select line coding
12 Click on Clk Gen corresponding to the M8045A (M1) and set the
f
requency as 10 GHz.
13 Click on Data In corresponding to the M8046A (M2) and select the line
coding PAM-4.
14 Enable the output of the pattern generator by clicking on the Output
State button as shown in Figure 27 on page -62.
Figure 27 Enable pattern generator output
In the CLK/2 mode, for symbol rates above 25 GBaud, an external
bandpass filter has to be used on the clock input of M8046A. The filter
has to be removed for symbol rates below 25 GBaud. However, in the
CLK/1 mode, no external bandpass filter is required.
When the line coding “PAM-4” is selected for the loopback mode, it is
recommended to adjust the pattern generator data output de-emphasis
for the post cursor for error free operation (e.g. +0.05 at 25 Gbaud).