Regarding the Issue of Frequency Modification for nRF54L15

[listenYes]

Hi!
    I'm currently attempting to develop software using the nRF54L15 and NCS v2.9.0 (previously, I used the nRF52840 and NCS v2.9.0). Both development processes are carried out in the VS Code environment.
    However, I've noticed abnormal issues during BLE Mesh debugging. The specific manifestations are as follows:

1. In the nRF Connect plugin, the nRF54L15 - DK development board often cannot be erased. When I click the "erase board" button, an error occurs. At this time, the chip seems to be in a locked state, and I have to use the "Erase all" function in the "Programmer" software to fix it.
2. Every time I click the "Debug" button in the nRF Connect plugin, it takes a long time (more than 10 seconds) to enter the debugging interface. Moreover, debugging fails and cannot proceed, which is manifested as follows:
   (1) In VS Code, except for the "Stop" and "Pause" buttons, other debugging buttons are grayed out and ineffective (I think the debugging is already running at this time). After clicking the "Pause" button and then clicking the "Restart" button, subsequent debugging will most likely fail.
   (2) In OZone, when clicking the "Download & Reset Program" button, it will most likely prompt "UsageFault", and only in a few cases can it jump to the debugging interface.
   However, the nRF52840 and nRF52833 development boards work normally. My supplier told me that the reason is "since Bluetooth is used, debugging will disrupt the timing, which in turn leads to hardware failures." But this cannot explain the fact that the same project can be debugged on the nRF52840.
   So I suspect that the debugging failure is caused by the nRF54L15's CPU running too fast (because its default frequency is 128MHz). I want to reduce its frequency to 64MHz, the same as that of the nRF52840. However, I can't find the macro definition (similar to the CONFIG_xxx macro definition) to modify the frequency. But the datasheet shows that the nRF54L15 can be selected between 128MHz and 64MHz. So how can I switch to the 64MHz frequency?

[Elfving]

Hi,

Is this a completely default DK without anything soldered on or switches flipped? Does this work completely on the nRF52840DK? (I guess it could be the nrfutil or nrfjprog version that is at fault).

Do you have the newest version of the extension installed?

Regards,

Elfving

[listenYes]

Hi,

Yes!

To verify the above issues, I rebuilt the development environment on a new Windows 11 (64-bit) computer, so the software and extensions should be up-to-date. The development board is also an official board purchased from the vendor, completely unmodified. The example program used is "mesh light" (relative path: v2.9.0\nrf\samples\bluetooth\mesh\light), which was compiled and run directly without any changes. The nRF52840DK is indeed working properly for debugging. Now I want to modify the CPU frequency of the nRF54L15-DK to 64MHz to test its functionality. However, I clearly haven't found any relevant macro definitions that can reduce the main frequency from 128MHz to 64MHz.

Regards,

Listen

[Elfving]

listenYes said:

Now I want to modify the CPU frequency of the nRF54L15-DK to 64MHz to test its functionality. However, I clearly haven't found any relevant macro definitions that can reduce the main frequency from 128MHz to 64MHz.

I do not think that is what is at fault here, this should be possible with a brand new DK.

Are you able to debug when flashing any other samples? Do you flash the DK using the onboard debugger?

Regards,

Elfving

[listenYes]

Hi

Yes!

I'm using the onboard debugger. I directly connect the data cable to the ports on the development board for debugging and development (the nRF52840DK uses a micro USB, while the nRF54L15DK uses a Type-C USB). If it's a "Hello world" example program, there's no problem at all. I can debug both the 52840 and 54L15 development boards normally, whether in VS Code or Ozone. Meanwhile, I've also found a way to reduce the frequency of the 54L15. After testing, I found that the problem still exists, which indeed has nothing to do with the frequency. However, I've now discovered a new situation when debugging the "mesh light" example program using the 54L15 - DK board. Regarding the second point I mentioned before, "Every time I click the 'Debug' button in the nRF Connect plugin, it takes a long time to enter the debugging interface." After my observation, in fact, it's not a malfunction. It takes more than ten seconds to enter the debugging interface (at this time, only the pause and stop buttons work), and it takes more than thirty seconds or even longer to complete the initialization of the debugging interface (the run and other buttons become effective). Secondly! If I erase the development board in VS Code, directly click "Debug with Ozone", and then click the "Download & Reset Program" button in Ozone, Ozone will pop up a "UsageFault" error and debugging cannot be carried out. If I erase the development board in VS Code, then click the "Flash" button, or click the "Debug" button to enter debugging and then exit, the program will be downloaded to the chip first. Then, if I click "Debug with Ozone" and then click the "Download & Reset Program" button in Ozone, Ozone will become available for debugging. Although the "UsageFault" error still pops up occasionally, it can jump to the main function after resetting, and the "Step over current subroutine" button, "Step into current subroutine" button, and breakpoint operations are all available. So it seems that Ozone can't directly download the program for debugging and needs to download the program through other means first. Also, Ozone debugging is not very stable. If I click the "Resume program execution" button to let it run completely, stopping or pausing at this time will cause a "UsageFault" error. But it can continue to be debugged after resetting. I don't know if such problems are caused by the Bluetooth protocol stack, but they've really brought great trouble to my development. Because when using VS Code, entering the debugging interface is extremely slow, while using Ozone can't ensure stable debugging.

[Elfving]

Hi,

listenYes said:

Regarding the second point I mentioned before, "Every time I click the 'Debug' button in the nRF Connect plugin, it takes a long time to enter the debugging interface.

I've just tried this with a new 54L15DK. With the device recovered, I'm pressing debug in the VSC actions panel. It then takes about 10s for the flashing to finish (I follow along on the terminal to see what it is working on) and then about 4 for the debug interface to open. I guess how quickly this happens depends on how beefy your computer is, though mine did spend 14s without it really being slow. 30 seems a bit too slow though.

listenYes said:

If I erase the development board in VS Code, directly click "Debug with Ozone", and then click the "Download & Reset Program" button in Ozone, Ozone will pop up a "UsageFault" error and debugging cannot be carried out.

I might be seeing the same thing here, though this is a hardfault.

Could you make sure that you've updated to the latest version of the NCS extensions, and provide me this support info?

Regards,

Elfving

[listenYes]

Hi,

Here is my configuration parameters:

This is the JSON file I obtained:

// IMPORTANT: The following data can contain sensitive or confidential information about your environment.
// If you do not want others to see this information, make sure to remove it before sharing the data.

// For help and support, visit Nordic Semiconductor's DevZone at https://devzone.nordicsemi.com/.

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I've masked some of its content (since this post is public). The masked content is as follows:

The data of serialNumber:

Some environment variable paths under environment:

Some environment variable paths under inherited:

If you directly click the "Debug with Ozone" button and then click the button in the top-left corner of Ozone (the red-bordered section), it will result in the following HardFault error pop-up:

If you first click the "Flash" button to download the program to the chip in advance, then click the "Debug with Ozone" button, and finally click any one of the three buttons in the top-left corner of Ozone (the red-bordered section), it will result in the following UsageFault error pop-up:

However, clicking the reset button occasionally allows debugging to proceed.