nRF53 NET core flashing, only first 4 KiB flashed unless a mass erase is performed.

[Andre]

I am not sure whether this is an issue with the nRF53 Engineering Example or with the SEGGER software. 

I don't see any errata describing the behaviour I am experiencing:

When I try to run an application on the NET core, it will only write the first 4 KiB to flash. 

I have to do a mass erase of the NET core for the whole application to be written to flash.

I am using SEGGER software version V6.86e with GDB version 9.2

[Einar Thorsrud]

Hi,

Do you see this issue with SEGGER software V6.86f as well? (That includes a fix for programming the nRF53 network core). If not, which PDK version do you have?

[Andre]

Version V6.86f gives different problems. It seems not flash at all.

It keeps giving a popup saying the device is secured. Regardless whether I answer Yes or No, the SEGGER software seems to hang after this. I am using a PDK version 0.8.0

[Einar Thorsrud]

Hi,

I see. I have not been able to reproduce any of the issues using 6.86e or 6.86f with nrfjprog, but perhaps it matters which J-Link tool you use and how. Can you elaborate on how you reproduce this?

[Andre]

I am using Eclipse with the GNU MCU Eclipse plugin and GDB version 9.2. 

I have configured two projects, one for the application core, and one for the network core.

1) I launch a debugger session for the Network Core, 

2) I launch a debugging session for the Application Core,

3) I start the Application core,  (it will execute nrf_reset_network_force_off(NRF_RESET, false);  )

4) I start the Network Core. 

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Using version 6.86e:

Using JFlashLiteExe, I first erase the Network core.

I follow these steps for an empty loop net application.

Result: The application runs as expected.

Then, I will create an application that changes the locations where certain code resides in flash. I archieve this by adding a call to sprintf in my code. When I run the network core, it will hard fault. The location of the hard fault is beyond 0x1001000. The disassembly of the code shows "<UNDEFINED> instruction: 0xffffffff", indicating the flash has not been written.

When I perform a flash erase using JFlashLiteExe, and then perform these steps again, the network core runs as expected. 

---

Using version 6.86f: 

The behaviour is little different then I had before (Previously I swapped the order of launching) 

When I try to erase the network core using JFlashLiteExe, the device is secured message pops up.

When I choose yes, the JFlashLite indicated it succeeded. 

When I launch the network core, the popup comes again.

When I choose yes, the launch fails with "Starting J-Link GDB Server timed out."

When I choose no, the launch continues, but it seems without flashing, as the application halts at 0xdeadbeee. (rather then waiting for the application core to release the network core) 

[Einar Thorsrud]

Hi,

I am a bit surprised that you get this behaviour using 6.86f, as that fixes a known issue with segger complaining about the network core being locked. Perhaps this is related to the GNU MCU Eclipse plugin somehow? That is not something I have experience with or Nordic supports, though.

Apart from the issue fixed in 6.86f, programming and debugging should work well using 6.86e or higher using the segger tools themselves.

[Andre]

Hi,

Looking at SEGGER's change log, it says

"Device protect check for nRF5340_xxAA_NET core of nRF5340 series device according to new hardware revision (v0.9.0 or newer), adapted. SECUREAPPROTECT bit only for nRF5340_xxAA_APP core implemented."

Could it be that this issue occurs because I my PDK is version 0.8.0?