nRF52840 readback protection after reset

[Lecram69]

Hi,

Build an application without SD but with MBR. MBR is at address 0x0000 - 0x1000. Application is at 0x1000 - 0xF0000. At the beginning of the application is the ISR vector. 

Application is also working after programming. 

However after a reset the application goes into readback protection. Did I forget something to do when disabling and removing SD? is there some docu available? 

Maybe the reset handler is not found? How can I debug this?

[Hung Bui]

Hi Marcel, 

If you are using revision 3 of nRF52840 chip (Fx0) the readback protection is enable by default after a reset if it's not disabled by the software. Please have a look here.

So it's normal that the application goes into readback protection if you don't disable it in the software. 

If you want to disable APPROTECT, please follow the instruction in the documentation. 

[Lecram69]

Seems like it is rev 3 nRF52840. Thanks!