Why SystemInit or startup_nrf51.s could not be reached

[Luis Alberto]

I'm working with a custom hardware board made by hand which works properly, but since we make a batch with a pick and place machine, something seems to be wrong with the board. We are using the same PCB board and components. The behaviour of the bad boards is that they are not able to reach the SystemInit from a simple blink project (with no soft device) in which the good one does. I set a break point in the arm_startup_nrf51.s first instructions but it does not stops there, instead it is stopped somewhere else, the callstack is says 0xFFFFFFFE. Also I've notice that the erase process (Full erase) takes longer in the board that works. I just can think that is a hardware issue, but I have meassure the voltage supply, crystal and everything seems to be the same as the working board.

Any guess or test to know what could be wrong? Thanks.

[Nguyen Hoan Hoang]

Check the debug console to see if it detects the processor ID properly. Try to lower the speed of jtag. You may have bad solder joints or a short circuit on the jtag lines. This may explains the 0xffffffff values hence erase was very fast.

[Luis Alberto]

Well, I did lower the programing frequency to 20KHz just to be sure and it did work. I'm now testing how far can I go without getting problems. Weird thing that the verification process did not notice anything. Thanks!