https://devzone.nordicsemi.com/f/nordic-q-a/5036/pstorage_store-and-pstorage_update-execution-timeHello Where can I find operating characteristics of pstorage_store and pstorage_update? Actually, I observe that about 100 ms are needed to update 4 bytes data. For me, it seems a little long for an internal memory access. Is it normal ? en-USTelligent Community 13Wed, 07 Jan 2015 11:46:18 GMThttps://devzone.nordicsemi.com/thread/17756?ContentTypeID=1Wed, 07 Jan 2015 11:46:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:46072c78-b291-4e62-b196-8d6ab6bcb8edting&#178;<p>Thank you very much!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/17755?ContentTypeID=1Wed, 07 Jan 2015 10:44:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a98c17a0-b79c-4d40-8910-8ed2db87b44fStefan Birnir Sverrisson<p>Hi</p> <p>According to the nRF51822 PS v3.1 table 61, flash write operation takes up to 46.3us and flash erase takes up to 22.3ms. Flash erase can be performed on minimum a whole page, i.e. 1024 bytes. Flash write can be done on minimum one word, i.e. 4 bytes.</p> <p>What happens when you issue an pstorage_update is as follows:</p> <ul> <li>The so called swap page is erased</li> <li>The data of the updated page that is not being updated is written to the swap page</li> <li>The page is erased</li> <li>The update data is written to the flash page</li> <li>The the remainder of the page that is not to be updated is written back to the page from the swap page</li> </ul> <p>So the pstorage_update command actually contains at least two flash erase commands and multiple flash write commands, which explains how long it takes.</p><div style="clear:both;"></div>