Flash memory erased issue

[pkr2258]

hello,

Download the app uart example of central, turn off the power,

then turn on the power again after a few days When I tried to do it, nothing happened.

So, after verifying, the flash was deleted as shown below.

- sdk 17.1.0

- nRF52-DK

When re-writing again, the motion is normal... 
I wonder what the problem is.

thank.

[Sigurd]

Hi,

What version of the DK you are using?

[pkr2258]

hello,

The version is below.

nRF52-DK  ( PCA10040 / 3.0.0 / 2022.10 )

SDK 17.1.0

thank

[Noah_iR]

I'm developing a product with the nrf5340, and I've experienced the same symptoms twice.

[Sigurd]

Hi,

pkr2258 said:

nRF52-DK  ( PCA10040 / 3.0.0 / 2022.10 )

This uses the latest version of the nRF52832 IC.

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/dif.html?cp=5_2_0_15_1#concept_udr_mns_1s

By default, access port protection is enabled on this device. If you did not take any steps in order to keep access port protection disabled, then you likely erased the flash when you connected the debugger and tried to read out the flash.

[hyojoon]

Hi all

nrf5340

Zephyr v3.1.99-ncs1-fork (NCS v2.1)

I found the same symptoms.

Most of it happened during aging.

net core and app core all deleted.

They were samples that we already flushed several times.

And there was no flash approach using J-lnik or other debug ports during aging.

To be precise, the aging samples(4 samples) did not work, and it was confirmed that all flash was erased through j-link.

There was no message that the protection was hung when connecting the j-link.

[Sigurd]

Hi,

If a device for some reason stops functioning, for any number of reasons(a bad battery, some external damage, etc), and you try to connect a debugger to it, and the device has access port protection enabled, you are then not able to read the flash. A CTRL-AP.ERASEALL operation from the debugger will erase the flash, and open the access port protection.

Using J-link, you might get this kind of pop-up.

https://infocenter.nordicsemi.com/topic/ps_nrf5340/debugandtrace.html?cp=4_0_0_7_1#access_port_protection

[hyojoon]

Yes I know that popup/

But When I was connect sample to J-link 

The pop-up window did not appear.

As mentioned above, it was fusing a few times. In other words, the protect function is already disabled.

When connecting the problematic sample to j-link, the pop-up did not occur, and 0xFF was read from all flash at the time of read.

[Sigurd]

Hi,

hyojoon said:

nrf5340

hyojoon said:

As mentioned above, it was fusing a few times. In other words, the protect function is already disabled.

I'm not sure what you mean by fusing here. The case in this thread is originally created for nRF52832. If you are having issues, please create a new case for your issue: https://devzone.nordicsemi.com/support/add