Programming error JLinkARM.dll CORESIGHT_WriteAPDPReg

[Roger Clark]

Can someone tell me what these errors actually mean

JLinkARM.dll CORESIGHT_WriteAPDPReg returned error -1. JLinkARM.dll CORESIGHT_WriteAPDPReg returned error -102.

When programming a custom nRF52832 board using JLink.

I seem to intermittently get them, and no matter how many times I run nrfjprog --reset --f nRF52 it keeps giving the error

Strangely if I open in JFlash and try repeatedly to connect, after about 5 attempts the problem seems to resolve its self.

I'm wondering if this is a power supply problem ?

But knowing what the message means would be useful

Thanks

[Roger Clark]

Update.

I have changed the code which is running on the board, to the beacon example (Hex file for the PCA10040) to rule out something in my code, but I get the same problem.

There seems to be some difference between what JFlash does to connect and what nrfjprog does, because I can run nrfjprog over and over again, to reset the nRF52 and it never connects

However if I run JFlash it seems to connect after a few attempts.

Then once JFlash has successfully connected I can run nrfjprog over and over again, and it works OK.

But after a few minutes of not interacting with the board, nrfjprog fails to connect.

I've checked the supply voltage and its 3.3V, so I don't think its a supply voltage issue.

I could be a supply noise issue, but get the same problem when its running from its internal lipo cell (via a regulator), but I will look at the 3.3V with a scope to check for noise