External PCIe clock reference


I have a system with two PCIe hosts (both roots) accessing other devices through a PCIe switch (one of the hosts is behind a Non-transparent port).
Because of other reasons, I need to generate the PCIe reference clock externally to the Jetson module, so my question is, how can I make the PCIe links in the module work with an external clock signal? Is that even possible?


I’m afraid Tegra doesn’t support this (PCIe reference clock being taken from the external sources) configuration.

Hi @vidyas thanks for your reply.
I was affraid of that… however, my understanding is that agents in a PCIe bus can actually use different reference clocks. Isn’t that right?
So then I could actually have the Jetson module and the PCIe switch connected to it working with different clocks and I would not need to use the same clock i both.
Do you think that is possible? Do you think any modifications/configurations are needed for that?

You are right that PCIe spec supports such configurations but as I mentioned, Tegra HW doesn’t support it.