Writing/Erasing the flash with radio on and BLE communication on-going.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Amanda Hsieh — Mon, 02 Sep 2019 09:27:18 GMT

Hi Justin,

As my colleagues explained in this post. I suggest you study the fstorage library's handling of that return code. See line 511 of nrf_fstorage_sd.c and flash_fstorage example in SDK 15.3 for the detail.

-Amanda H.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Justin — Fri, 30 Aug 2019 13:49:24 GMT

[quote userid="77782" url="~/f/nordic-q-a/51216/writing-erasing-the-flash-with-radio-on-and-ble-communication-on-going/207118"][/quote]

NRF_EVT_FLASH_OPERATION_SUCCESS - The command was successfully completed.
NRF_EVT_FLASH_OPERATION_ERROR - The

Where to add the callbacks for these events in my application? Any code example would be of great help.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Amanda Hsieh — Fri, 30 Aug 2019 11:32:34 GMT

Hi,

In Experimental: Flash Storage/Writing data section, you can see how to handle the event return from nrf_fstorage_write().

sd_flash_write() will be communicated to the application with exactly one of the following events:

NRF_EVT_FLASH_OPERATION_SUCCESS - The command was successfully completed.
NRF_EVT_FLASH_OPERATION_ERROR - The command could not be started.

-Amanda H.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Justin — Thu, 29 Aug 2019 19:03:26 GMT

Hi Amanda,

Thanks for your valuable inputs. I am able to write into flash using Flash Storage.

My question is if the write fails is there any event generated so that it can be retried?

I want to specifically use Experimental Flash Storage or sd_flash_write() API.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Amanda Hsieh — Thu, 22 Aug 2019 13:24:56 GMT

Hi,

[quote user="johnmjustin"]how FDS works?[/quote]

Please see this Experimental: Flash Data Storage:

FDS uses Experimental: Flash Storage as the backend to write to flash. Flash Storage, in turn, relies on the SoftDevice to execute the write. Flash Data Storage supports synchronous read operations and asynchronous writes.

[quote user="johnmjustin"]Where do we give the memory address where I want to start writing[/quote]

Please see Flash Storage.

[quote user="johnmjustin"]I am confused when should I use sd_flash*** API and FDS.[/quote]

FDS is a file system, and with sd_flash you just write bytes directly to flash.

you can read about the benefits of FDS here, (the points under "The module has been designed to provide the following benefits: ")

When the SoftDevice is enabled, flash operations should be done using the sd_flash_xx api. For writing to flash, sd_flash_write() should be used. To simplifying storing data to flash, the library flash data storage (FDS) can be used.

-Amanda H.

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Justin — Thu, 22 Aug 2019 03:12:25 GMT

HI Amanda,

Thanks for your email.

I am not able to understand how FDS works? Where do we give the memory address where I want to start writing? In the input parameter of structures no where we provide memory address.

I am confused when should I use sd_flash*** API and FDS. Also to write few bytes should I go with sd_flash_write() api or FDS?

RE: Writing/Erasing the flash with radio on and BLE communication on-going.

Amanda Hsieh — Wed, 21 Aug 2019 10:57:34 GMT

Hi Justin,

If you look at the NVMC — Non-volatile memory controller documentation, you'll see that there is an NVMC->CONFIG register where you can set the flash to read enable, write enable or erase enable. The SoftDevice takes over control of the NVMC when it's running which is why you have to use the sd_flash_page_erase() API when the SoftDevice is active instead of programming the NVMC directly.

When the SoftDevice is enabled, flash operations should be done using the sd_flash_xx api. For writing/erasing to flash, sd_flash_write() / sd_flash_page_erase() should be used. If you try to access the NVMC directly when the SoftDevice is enabled, it will result in a hardfault. See this, this and this link.

To simplifying storing data to flash, the library flash data storage (FDS) and nRF5 SDK v15.3.0: Flash Data Storage Example can be used.

-Amanda H.