CANNOT FLASH softdevice into NRF51822 WITH NRFGO

[Fenglong]

I've been working with writing and erasing flash. And somehow I can't flash softdevice 6.0 into the NRF51822 G0 chip with NRFGO. The error information poped up is "An error condition was detected in the JLinkARM DLL".

Still I can erase the whole flash with NRFGO.

My NRFGO is 1.16.0.3031

Based on the previous discussion related to this topic, I also tried typing the following in the J-Link commander. But still doesn't fix it. " r w4 4001e504 2 w4 4001e50c 1 w4 4001e514 1 qc "

[Hung Bui]

Hi Fenglong,

We have a command line tool: nrfjprog.exe included in the SDK for flash programming and erasing. Could you try to use that tool and let me know the result ? (You can click cmd and type nrfjprog) I would prefer a screen shot.

I suspect that there maybe an issue with Segger Jlink driver. Could you try to uninstall and install the latest one ?

[Fenglong]

Thanks a lot, Hung!

Actually I'm able to recover the device now. Let me share my experience because that may be useful to other developers.

After the power source is removed, it took time for the device DVDD to GND voltage to drop to 0V. I couldn't recover the device yesterday, because I didn't wait long enough for the voltage to fully decay before re-applying the power source to the device.

This may be related to the power management design of the chip. So for future reference, we just make sure the DVDD to GND voltage drops to zero and then add back the power.

I haven't tried the nrfjprog.exe. If there is a pure software solution to fix the problem, it will be much better. I will keep you posted related to this.

thanks, Fenglong

[Hung Bui]

Hi Fenglong,

Most likely you have a large capacitor connected on the VDD that requires a long discharge period. The device won't enter brownout reset mode until the supply voltage drops below 1.8V.