https://devzone.nordicsemi.com/f/nordic-q-a/22167/protect-flash-region-from-fdsHi, So I have a HEX file with unit specific data that I upload to 0x00062000. This data is about 80kb so it leaves some space incase I need a bootloader in the future. Furthermore I store some data generated from device usage with the FDS. Everythingen-USTelligent Community 13Mon, 22 May 2017 10:53:09 GMThttps://devzone.nordicsemi.com/thread/87131?ContentTypeID=1Mon, 22 May 2017 10:53:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:896f7e2f-64c6-4bbd-825c-368b771ba6a0Petter Myhre<p>FDS shouldn&#39;t overwrite your data as long as you have configured correctly.</p> <p>The default setting is:</p> <pre><code>#define FDS_VIRTUAL_PAGES 3 </code></pre> <p>Then the three last pages of flash will be used by FDS (as long as you don&#39;t have a bootloader).</p><div style="clear:both;"></div>