[nRF52840] What do the addressess [0x10001200-0x1000121F] mean

[Ben.su]

Hi Nordic guys.

I come with that case, the nRF52840 works unexpectedly after erasing the chip. That's

Background

1. Erase the chip
   1. By JFlash; or
   2. By Programmer.
2. Flash the hex which built with the source code
3. Reboot

Result

1. No log output from UART;
2. I don't even know if the nRF52840 runs or not.

Analysis

1. Read back the entire flash from the one which was erased and the one which was NOT erased;
2. Compare the hex files;
3. Find that it is only the last bit difference at address 0x1000120C.

Question

1. Why does the flash map of nRF52840 in JFlash contain the address [0x10001000 - 0x10001FFF]?
2. What does 0x1000120C mean;
3. How can I fix this issue when I erase the chip?

[Susheel Nuguru]

Not sure if I understood the issue clearly.

Are you saying that when you erase the chip there is a bit that is not being erased at a particular address? 

Find that it is only the last bit difference at address 0x1000120C.

It is the NFCPINS configuration in the UICR page.

[Ben.su]

Hi Susheel,

That's the case. I'm using pins P0.09 and P0.10 which are the NFCPINS. And I think I can set them as the GPIO pin with the configuration CONFIG_NFCT_PINS_AS_GPIOS=y.

Thanks for the update.

BR

Ben