What does it mean when debugger head lands on 0x00000000?

[Tyler]

I'm running on a nrf51822 chip, using Keil and a JLink Segger programmer. I'm running on SDK 12.2.0 and I believe I was correct in choosing pca 10028 s130 but I'm not 100% sure. I had to modify the target device when I started with the ble_app_template.

When I am running the debugger, It will go through the power manager loop 1 or 2 times, reset to be beginning, repeat a few times, and then the execution code jumps to 0x00000000 and loops there forever. If I operate outside debugger mode, it just loops 1-6 times and then resets (I know because I am advertising a loop count as part of some ble beacon information).

[Daniel Wang]

I think that means that the program is reset. After a reset, the vector table is usually defined at the start of the memory space (address 0x00000000).

Have you tried debugging? devzone.nordicsemi.com/.../

Are you using a nRF51-DK? If so, it should not have been necessary to change target device...

[Tyler]

Thanks for the link to that thread, I'll take a look at it. I am actually developing on a board from a manufacturer who makes watch devices in china and sells to whoever. I actually just opened up an nrf51422 devkit (hopefully the model difference won't throw off what I learn too much) so I can load my firmware onto there and activate some pins for uart to debug with.

[Tyler]

I just tried putting a break point on the app_error.c app_error_handler_bare (the other one wasn't compiled in) function and it doesn't appear to be called before 0x00000000 gets targeted. Is this because I am not using the app_error_handler instead of bare?

[Tyler]

Well, I just answered that question. I put in 'DEBUG' in the pre-processor symbols and it calls the app_error_handler function instead now and still doesn't call it before hitting 0x00000000.

[Daniel Wang]

Have you flashed the soft-device? You should flash soft-device S130 v.2 if you use sdk 12.2. You can flash the softdevice using nrfjprog command-line