Transceiver reference lock issue

Hi,

I describe another observation of this issue.

Some of the failed boards fail at High temperature only, I think it means High temperature of Arria 10.

At the cool duration, such boards work fine, rx_is_lockedtoref goes to High and it receives rx data correctly. And after heat up, sustaining supplying power to the board, the interface is continuing fine work. It would mean all clocks and connections are fine even at the high temperature.

However, after power off and on once, rx_is_lockedtoref does not go to High after configuration.

It looks, capability for lock-to-ref.

How about that? And does anyone have any idea?

Thanks,

TerryU