PCIe Clock Jitter Tool
We have been using the Si5338 as clock source for several PCIe products with very good results. Long/lossy links have been stable and error free for years. So I believe our implementation is good.
The clock is connected with two coaxes directly to the scope and the eye diagram as measured with the scope is super-clean in infinite persistence.
When using the PCIe Clock Jitter Tool, I'm seing strange results with big data sets from a Lecroy Waverunner 8404. The Waverunner reports nothing suspicious regarding min/max edge rates, but the Jitter Tool reports increasingly higher edge rates the bigger a data set is. in a 200k edges data set, the tool reports an average edge rate of about 2.0 V/ns, and a max edge rate of almost 26 kV/ns...
Also there is significant stepping in the TIE, Period, and Cycle-Cycle waveforms.
Hope you can look into this, as the tool is really useful. I've attached the report output.
I can provide scope data files on request.
I'm not 100% sure that this is jitter tool issue. It may be SI issues, or scope issues as well. But as the scope measurements ar so different from the Jitter tool measurements, I'm posting here first.
Oct 28 2017, 4:44 PM