Flash write when BLE is on

[Miguel Ferreira]

Hi,

I have two questions regarding flash writes when BLE is on. So, in a code Im currently working on the sdc flash API is being used when BLE is on (sdc_soc_flash_write_async). I would like to know:
  - Why we need the Async writes when BLE is being used ?
  - What is the difference between using the sdc flash API and the NVS Zephyr module ?

Thank you!

[Vidar Berg]

Hi,

The flash operations need to be scheduled to run between RADIO events to not interfere with the BLE protocol, hence the requirement to use async APIs. You can read more about this in the 'Flash API timing' chapter of the Softdevice controller documentation. Zephyr modules such as NVS will do the same when writing or erasing flash while BLE is enabled, but then through the APIs implemented in soc_flash_nrf.c here: https://github.com/nrfconnect/sdk-zephyr/blob/main/drivers/flash/soc_flash_nrf.c 

Best regards,

Vidar

[Miguel Ferreira]

Thanks for the reply!

So using the NVS API would be the suggested approach correct ?

[Vidar Berg]

No problem. Yes, in general, we recommend using the Zephyr modules to manage flash storage (NVS, Settings, etc.). These modules will work both with and without the Softdevice controller present. 

[Miguel Ferreira]

Thanks very much Vidar Berg  for clarifying my doubts! Will close the ticket :)