how to erase application only without erasing uicr with nrfjprog

[helen]

Excuse me：

                      The chip can individually erase the application without erasing the uicr with nrfjprog？Which nrfjprog command is used to erase  the application only，I want to program the .hex file only without erasing uicr.

[Jared]

Hi,

Use the --sectorerase option. See nrfjprog --help to get a complete list over all of the commands and sub-commands.

 If --sectorerase is given, only the targeted non-volatile memory pages, excluding UICR, is erased

regards

Jared 

[helen]

After I only erased the application, I failed to program the new .hex.I want to update the .hex without removing the previous uicr.

[Jared]

Hi,

The hex has to cover the same area as the previous one, as sectorerase will only erase the area of the new hex. If it doesn't cover the area, and you try to program a new hex, nrfjprog will sense that the area is already written to and will return an error.

Alternatively, you can try to use nrjfprog --erasepage and manually erase the application and then use nrfjprog --program to flash the new application. 

regards

Jared