Arria 10: Remote Update may brick FPGA and Factory Fallback won't work

Hello Farabi,

thanks for the reply. As mentioned before, if I enable the watchdog as described in your post, the fallback mechanism kicks in.

But this leaves me with 2 critical questions:

1. When we do not use the watchdog (RU_WATCHDOC_ENABLE = 0). The factory fallback does not work when the application image is misaligned. Why does the factory fallback not happen in this case? I expect a misaligned application load to trigger a CRC error.
2. Our application design is not actively serving the watchdog. We are using the Avalon IP "Remote Update Intel FPGA IP" Version 19.1.0. We do not set any of the Watchdog Registers in the application image, so I would have expected that the watchdog would trigger and cause a factory image fallback. But his is not happening. The documentation indicates, that a watchdog timeout may occur after entering application user mode. Hence I would expect that an application image, that does not service the watchdog would trigger a factory fallback. Why is this not the case?

Having these questions open gives the whole fallback mechanism an unreliable touch. So I would be very thankful if this behavior could be clarified.

Thanks.

kind regards

Fabian