https://devzone.nordicsemi.com/f/nordic-q-a/1595/softdevice-s110-0x20000000---0x20000003-is-specialHi there, We&#39;re looking to use the entire 16 KB of RAM on the nRF51822 when the S110 is disabled. We&#39;ve come across an odd case, where doing this: memset(0x20000004, 0x0, 0x1FFC); works OK: that successfully zeroes all the memory from 0x20000004en-USTelligent Community 13Wed, 12 Feb 2014 11:04:21 GMThttps://devzone.nordicsemi.com/thread/7054?ContentTypeID=1Wed, 12 Feb 2014 11:04:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b0a555cf-233a-415d-82c7-29e3c0d6e5feOle Morten<p>That document is definitely recommended reading for anyone even considering working with the S110. Good luck! :-)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/7053?ContentTypeID=1Wed, 12 Feb 2014 11:03:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8af4bcd3-2566-4204-8148-dd8298187b34Andre Pang<p>Oh, well. That sounds like a rather handy document to read, then :). Sorry, I checked all the documentation I had, but appear to be missing that one! Cheers Ole.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/7052?ContentTypeID=1Wed, 12 Feb 2014 09:53:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b2417640-5be7-4385-b29e-85903030acbcOle Morten<p>As you can see in the <a href="https://www.nordicsemi.com/eng/content/download/13238/213065/file/S110_SoftDevice_Specification_v1.2.pdf">S110 Softdevice Specification</a>, the S110 reservers 4 bytes of RAM even when not enabled, so you&#39;ll not be able to use those 4 bytes yourself, no matter if the S110 is enabled or disabled.</p><div style="clear:both;"></div>