nRF52840 Programming issues with CMSIS-DAP / pyOCD

RE: nRF52840 Programming issues with CMSIS-DAP / pyOCD

tomatosoup — Wed, 19 Apr 2023 22:12:04 GMT

Ok, I think my direction with that the module was locked is wrong.

The real issue was that this module doesn't have a 32k Crystal. Thus, running FW which relies on this crystal will put it into a kind of locked state.

The elpotronic programmer was still able to program it reliable as it also controls the power supply and thus was able to program it before the module tried to switch to the 32k crystal.

Adding these configs to prj.conf helped:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC_CALIBRATION=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_500PPM=y

RE: nRF52840 Programming issues with CMSIS-DAP / pyOCD

Sigurd — Tue, 18 Apr 2023 12:29:35 GMT

Hi,

[quote user="tomatosoup"]Now, the question is just why the elpotronic programmer was able to erase and program this locked module..[/quote]

Access port protection is disabled by issuing an ERASEALL command via CTRL-AP.

https://infocenter.nordicsemi.com/topic/ps_nrf52840/dif.html?cp=5_0_0_3_7_1#concept_udr_mns_1s

RE: nRF52840 Programming issues with CMSIS-DAP / pyOCD

tomatosoup — Mon, 17 Apr 2023 19:51:09 GMT

Oh no, I might have found the reason. This module might come locked by default. This command "fixed" it.

sudo openocd -f interface/cmsis-dap.cfg -f target/nrf52.cfg -c init -c "reset init" -c halt -c "nrf52_recover"

Now, the question is just why the elpotronic programmer was able to erase and program this locked module..