Does the SoftDevice handle disabling POFWARN on flash writes & erases?

[deangereaux]

We're using the nRF52840 along with SoftDevice s140 version 7.01 for a medical device.  Reviewing the nRF52840  Errata sheet, Rev2, there is an errata "242 NVMC: NVMC operations during POFWARN cause the CPU to hang."  The hang occurs when POFWAR is asserted during a write or erase operation.  The workaround is to disable POFWARN before a write and erase operation.  Obviously a medical device can not hang.   Digging further there is a SoftDevice API called sd_power_pof_enable() which  enables/disables the POFWARN signal.

My Question is:  Does the SoftDevice call this function before/after erase and writes (inside of sd_flash_write() and sd_flash_page_erase())?  Or is this something our code has to do?

Thanks,

Dean 

[ovrebekk]

Hi Dean

This is not handled by the SoftDevice, no, so it is up to the application to disable POFWARN before calling the sd_flash functions, and enable it again afterwards. Are you planning to use any SDK flash libraries, or are you going to access the sd_flash_ API directly?

Best regards
Torbjørn

[deangereaux]

Yes, we are using the FDS (Flash Data Storage) SDK library.

Thanks for the response.

Dean