Get stuck on mpsl_init(...) function

[witc]

Hi,
I have a custom board with nrf54l15 and it does not have a 32 kHz crystal, it only has a 32 MHz crystal. Sometimes the code gets stuck at this line:

err = mpsl_init(&clock_cfg, CONFIG_MPSL_LOW_PRIO_IRQN, m_assert_handler);

Can it be related to the 32 MHz crystal? For example, maybe the clock does not start?
It only happens sometimes, and because I do not have a 32 kHz crystal, I added in prj.conf:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=n

For the 32 MHz crystal, I am using only the internal C load (no external capacitors).
Can there be a problem with the C load setting, and should I try to change it?

Do you know what to do with this please?

Thank you.

[Edvin]

Hello,

What 32MHz crystal are you using? Do you have the datasheet?

And what did you set for your internal C load for the crystal? (And how did you set it?)

Best regards,

Edvin

[witc]

Hello,

I tried theese: ABM11W-101-32.0000MHZ-T3 and LFXTAL082129, 
I set internal C load like that in overlay:

&hfxo {
    load-capacitors = "internal";
    load-capacitance-femtofarad = <8000>;  // tj. 8 000 fF = 8 pF
};

Should I add anything else?

Thank you.

[Edvin]

I couldn't find the datasheet for the ABM11W 32MHz specific XTAL, but for the LFXTAL082129, it looks like this one:

https://portal.iqdfrequencyproducts.com/products/pn/LFXTAL082129.pdf

So the Load capacitance (CL) is 8pF. This is not what you should insert into the load capacitance in your overlay. 

According to:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/chapters/oscillators.html#ariaid-title2

 

Flip this around, and you will get:

C = 2*CL-Cpin-Cpbc

C = 2*8-1-0 = 15 pF.

So try setting:

&hfxo {
    load-capacitors = "internal";
    load-capacitance-femtofarad = <15000>;
};

I see that on the DK, we are also using an HFXTAL with 8pF load capacitance, and in the board files we use load-capacitance-femtofarad = 15000, so this should be correct. 

Try it, and see if that helps.

Best regards,

Edvin