https://devzone.nordicsemi.com/f/nordic-q-a/12364/regarding-flash-in-nrf51Hi. I am using PCA10028 board an SDK10.0.0. nRF51&#39;s Max flash size is 256KB. Q1. &quot;s130_nrf51_1.0.0_softdevice.hex&quot; size is 302KB already. How can we make HEX file less than 256KB? Q2. I used &quot;flashwrite&quot; example. It said &quot;start flash address en-USTelligent Community 13Tue, 08 Mar 2016 08:10:21 GMThttps://devzone.nordicsemi.com/thread/46761?ContentTypeID=1Tue, 08 Mar 2016 08:10:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8be3a2bf-0fbb-4bab-9063-4fb9c44b7b33roger.k<p>Thanks a lot</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/46760?ContentTypeID=1Mon, 07 Mar 2016 00:59:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6a94ed93-a47f-497b-b0a4-03a6c054fad5RK<p>Q1 - hex size irrelevant - hex files are around 2.5x as big as the actual binary they represent. Only the size of the binary actually matter.</p> <p>Q2 - what is 0x3fc00(261,120)? Where did you see that? 3fc00 is the last 1k of flash</p> <p>Q3 - this is explained in the nRF51 reference manual. They&#39;re configuration regions, UICR is programmable, FICR isn&#39;t.</p><div style="clear:both;"></div>