Fixing radio notification and flash write/erase conficts.

RE: Fixing radio notification and flash write/erase conficts.

Ole Bauck — Wed, 16 Mar 2016 13:58:48 GMT

Timeslot should not have these problems. Timeslot is more suitable than radio notfications for critical operations.

There is no plan to fix radio notification flash erata for s110, it will maybe be fixed for s130, most likely for s132. So use timeslot instead.

RE: Fixing radio notification and flash write/erase conficts.

Jordan Archer — Tue, 15 Mar 2016 21:54:56 GMT

Going to high priority didn't help. It reduced the rate of causing problems, but it still existed. As I recall, I think time slot showed some of the same symptoms. I didn't really have time to totally isolate what's going on.

Do you know for sure that time slot will solve the issue? I hate to re-spend the time doing that again and finding another hole. These take a while to chase down. Actually if I had one request, that would be to add a SD call to return a simple count of radio events. Then I could tell if something happened at any time during my processing.

And for references, I'm using S110.

Back to the original question. Is there any plan to fix the radio notification/flash notification errata?

RE: Fixing radio notification and flash write/erase conficts.

Ole Bauck — Tue, 15 Mar 2016 16:53:51 GMT

If you are using S132 you can utilize the pa/lna feature. Use fork to connect your own tasks to the pa or lna event or both:

NRF_PPI->FORK[ppi_set_ch].TEP = (uint32_t)&NRF_...->TASKS_...;
NRF_PPI->FORK[ppi_clr_ch].TEP = (uint32_t)&NRF_...->TASKS_...;

RE: Fixing radio notification and flash write/erase conficts.

Ole Bauck — Tue, 15 Mar 2016 16:27:04 GMT

Yes that is a problem. You can try to set the interrupt priority to APP_PRIORITY_HIGH and no other interrupt priority at that level. Most of the drivers should be using APP_PRIORITY_LOW, check nrf_drv_config.h. I cannot guarantee that the SoftDevice will not block the interrupt, but it should give the application some time during the connection event. I would recommend using timeslot instead.

RE: Fixing radio notification and flash write/erase conficts.

Jordan Archer — Tue, 15 Mar 2016 15:52:00 GMT

What I've caught is occasionally getting only one radio notification. This causes the radio notification to be out of sequence. It's rare, but if you do enough flash operations, this triggers. UART traffic may make this worse.

My theory is that because radio notification are interrupts, if softdevice signals a radio event, but that doesn't get serviced immediately because of a pending or active flash operation. The second radio notification interrupt is sent, before the first is serviced by the application level. So it only sees one interrupt when two happened. So it's not that the notification got lost. It's that the nature of radio even interrupts is that you can have only one pending.

RE: Fixing radio notification and flash write/erase conficts.

Ole Bauck — Tue, 15 Mar 2016 14:10:56 GMT

I meant do you get two radio notifications when doing a flash operation. If flash operation gives two radio notifications and no radio radio notifications is happening in between, then there will be no problem, only less time to do critical tasks. For example: flash start -> flash end -> radio start -> radio end will work fine, but radio start -> flash start -> flash end -> radio end will lead to time between radio start and radio end where the application thinks the radio is off. I will check with the developers if this is the case. I don't think timeslots should be affected by the flash operations, but need to check this also.

RE: Fixing radio notification and flash write/erase conficts.

Jordan Archer — Mon, 14 Mar 2016 20:03:29 GMT

It's been a while since I looked at timeslots, but I think it had the same problem. It's actually the radio notification that gets out of sync, not the flash. With active flash operations the radio free time could be shifted by quite a bit. Long enough to push you out of the window and then get stepped on by another radio operation. It changes the dynamics of the problem, but it still exists.

RE: Fixing radio notification and flash write/erase conficts.

Ole Bauck — Mon, 14 Mar 2016 10:43:20 GMT

You could use timeslot API instead, see this tutorial.

Don't you get two notifications on flash write/erase? If this is the case how can you get out of sync?