https://devzone.nordicsemi.com/f/nordic-q-a/21204/read-back-protection-and-code-in-ramRecently I have put some code of my application into RAM. When I do not enable read back protection mechanism everything works, however when I want to enable protecting my whole code and put some code into RAM I get into hardfault. I have tried differenten-USTelligent Community 13Mon, 10 Apr 2017 12:54:37 GMThttps://devzone.nordicsemi.com/thread/82984?ContentTypeID=1Mon, 10 Apr 2017 12:54:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5087bfa3-97df-473c-91e6-0e049ee02121Hung Bui<p>Hi AlBundy,</p> <p>You are correct, the readback protection mechanism on the NRF51 is not perfect and there is a security hole that allow a debugger to access the CPU&#39;s registers to read the content of the flash. But it should be enphasize that this is only possible when an attacker has physical access to a device and is able to connect a debugger to the product.</p> <p>If you looking for a better security of the flash code, I would suggest to use nRF52 where the issue is fixed.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/82983?ContentTypeID=1Mon, 10 Apr 2017 12:00:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0b3fcff5-325a-44c2-a0e4-60ea961a0813Al Bundy<p>I have placed quite a lot of code in RAM, so I guess it can be everything but probably it accesses some constant string array. But as far as I know it is still possible to dump memory of nrf51 even if read back protection is enabled?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/82982?ContentTypeID=1Mon, 10 Apr 2017 11:43:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cebd8500-ebab-4e2b-a358-e0271689bd9aHung Bui<p>Hi Albundy,</p> <p>What exactly you do in the RAM code ? Do you access any flash in code region 1 or code region 0 ? When RBP is enable either <code>all</code> or <code>region 0</code>, the code from RAM can&#39;t access those protected code area.</p><div style="clear:both;"></div>