https://devzone.nordicsemi.com/f/nordic-q-a/52378/uicr-and-ram-discrepanciesHI, I&#39;ve been using the Nordic Command Line Tools to do the following: program an example hex file to the SoC read the code, ram, and uicr registers and save to file A program a different example hex file read the code, ram, and uicr registersen-USTelligent Community 13Mon, 23 Sep 2019 10:44:13 GMThttps://devzone.nordicsemi.com/thread/211192?ContentTypeID=1Mon, 23 Sep 2019 10:44:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1bf595ee-8c41-40f8-979e-444a5471ff72Einar Thorsrud<p>Hi,</p> [quote user=""]I&#39;ve noticed that the ram file C never matches ram file A.[/quote] <p>This is expected. Unused RAM will be uninitialized, so even if you program firmware that does exactly the same and runs the code in the exact same way, the RAM content will still not be identical. Also, even with a dead-simple application that does not depend on the outside world, it would be difficult to get the same RAM content, since for instance, you would need to stop and read the RAM content at the exact same point (to get the same stack contact).&nbsp;</p> [quote user=""]I&#39;ve noticed the UICR files C and A match sometimes but not always.[/quote] <p>&nbsp;Using the&nbsp;--chiperase option will do a complete erase, including UICR. Therefore, the flash you read back after programming should be identical on all chips. A possible reason for UICR to be different is if the UICR is being written to by your firmware, which is sometimes done. Is that the case?</p><div style="clear:both;"></div>