it is seem that APPROTECT permanently enabled

[Ryon_pan]

Hello,

Every time I restart the power(power on reset) and then use the command nrfjprog to download, the following error will appear

After I use the nrfjprog --recover command, I can download the firmware, but the power on reset, and then the readback protection prompted above appears again when i download the firmware again.

So it seems as long as power on reset, readback protection will be re-enabled.

So my question is how to permanently disable readback protection?

[Jared]

Hi,

Ryon_pan said:

yes,i know how to read out these registers.but my question is how to keep readback protection disabled?

To disable readback protection you would have to:

1. Start with a CTRL-AP ERASEALL operation (nrfjprog -e)
2. Program code compiled with an MDK 8.44.1 or later, without ENABLE_APPROTECT defined.
3. Write HwDisabled (0x5A) to UICR.APPROTECT
4. Perform any reset to run the code. The programmed code from step 2 will open access port by writing to APPROTECT.DISABLE during start-up.

regards

Jared