How do I reboot FLPR?

[Fridtjof]

Hello!

We are developing a product which uses the FLPR cpu on the nRF54L15. We are basing ourselves on the Zephyr IPC samples and have copied the code from the Nordic flpr snippet into our project (so we are essentially using the snippet, but manually). This means FLPR is automatically set up and started on boot, which is practical but also a bit mysterious. Honestly I'm a bit unsure where the code which actually sets up and runs FLPR is in ncs.

Sometimes, FLPR hardfaults. In those cases it would be nice if the application cpu could reboot flpr only. How can we do this? Is it a matter of writing directly to the FLPR registers listed in the nRF54L15 PS, or are there library calls we can use?

Best regards,
Fridtjof

[Edvin]

Hello Fridtjof,

I asked our R&D, and there is no NCS API that you can use to reset the FLPR CPU only. You can reference the nordic_vpr_launcher_init(), and perhaps use some of that to reset the FLPR, but I imagine it is pretty similar to what you are already doing.

Best regards,

Edvin

[Fridtjof]

Thanks, Edvin. I thought this might be the answer, but getting confirmation is helpful. I will look into nordic_vpr_launcher_init() and the nRF54 datasheet.