Dual Application Code in Memory for NRF51822, 256kB flash &amp; 32kB RAMhttps://devzone.nordicsemi.com/f/nordic-q-a/31955/dual-application-code-in-memory-for-nrf51822-256kb-flash-32kb-ramHello All Supporters, I&#39;m developing one NRF51822 based product.so sometimes will need to update application codes as new features arrives.so if my user update(replace)application by OTA successfully and if that application code has bug or some otheren-USTelligent Community 13Mon, 12 Mar 2018 14:08:12 GMTRE: Dual Application Code in Memory for NRF51822, 256kB flash & 32kB RAMhttps://devzone.nordicsemi.com/thread/123954?ContentTypeID=1Mon, 12 Mar 2018 14:08:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b8bca042-96e5-4029-a47d-b5333adbf514H&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> <p>Our&nbsp;DFU does not provide this functionality.</p> <p>You cannot execute from a &quot;golden firmware&quot; version, as the DFU will invalidate this space upon upgrade. If you have a critical bug, you will need to patch this by releasing a new OTA.</p> <p>Even if this was possible, you&#39;re out of space:</p> <p>Total flash size of the nRF51x22_xxAA/AC : 256 kB</p> <p>S130 is 0x1b000 (108kB) long</p> <p>Your application is 80 kB</p> <p>The DFU is 21 kB</p> <p>SWAP_SPACE needs to be &gt;= application_size (80 kB in your case)</p> <p>108 + 21 + 80*2 = 289 kByte, which is greater than 256 kB.</p> <p>&nbsp;</p> <p>Best regards,</p> <p>Håkon</p><div style="clear:both;"></div>