https://devzone.nordicsemi.com/f/nordic-q-a/60193/nrf51822-unknown-mbr-data-from-flash-read-backHi, I have a question about unknown flash data from MBR area which start from offset 0x0000035C, 20 bytes data show as below. Data[20] : FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 01 00 00 20 I have done below two experiments: First one is programen-USTelligent Community 13Wed, 15 Apr 2020 11:29:39 GMThttps://devzone.nordicsemi.com/thread/244694?ContentTypeID=1Wed, 15 Apr 2020 11:29:39 GMT137ad170-7792-4731-bb38-c0d22fbe4515:323d6204-20f2-4461-887d-4e62333b101bEinar Thorsrud<p>Hi,</p> <p>This does not look familiar to me. Which SoftDevice version so you use?</p><div style="clear:both;"></div>