TASKS_CONSTLAT is not working on NRF54L15

[gandyhuang]

HI,

I am using "NRF_POWER->TASKS_CONSTLAT = 1;" to enable CONSTLAT, but when i  printf("TASKS_CONSTLAT %d",NRF_POWER->CONSTLATSTAT); the result is still 0; how can i  config it? thanks

  

[Emil Lenngren]

Do you use BLE or MPSL? In that case I guess you need to use this function https://github.com/NordicSemiconductor/nrfx/blob/32f47b3f6cadb175266e3a9c5faf4a730ad76ac0/drivers/include/nrfx_power.h#L361 because MPSL will also switch to/from constant latency during radio events. Note that I haven't tested if it works myself nor checked which Kconfig settings must be applied.

[gandyhuang]

HI,

 I am using the ESB_PTX sample,and set CONFIG_SOC_NRF_FORCE_CONSTLAT  in pro.conf, then i find that it will trigger NRF_POWER_TASK_CONSTLAT in soc.c(line 153), I set a breakpoint at line 160 to check the CONSTLATSTAT, but it's always disable;  

[Simonr]

Hi

We need some more time to reproduce this as I haven't heard back from the developers yet. I'll get back to you on Monday with another update here.

Best regards,

Simon

[Simonr]

Hi

We've tried reproducing this with the ESB_PTX sample, but the CONFIG_SOC_NRF_FORCE_CONSTLAT Kconfig option lets constant latency mode work just fine. Setting it directly in main.c also works on our end.

Can you share some details on your setup as well as upload your .conf file so we can take another look or provide some steps for us to reproduce this on our end.

Best regards,

Simon

[gandyhuang]

HI Simon,

I tested it again，you can find the code in attached file, set 

CONFIG_SOC_NRF_FORCE_CONSTLAT=y in pro.conf file, and "

LOG_INF("CONSTLAT=%d",NRF_POWER->CONSTLATSTAT); 

" in main.c; the log is below(DK: PCA10156 V0.8.1)

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
I: Enhanced ShockBurst ptx sample
D: HF clock started
I: Initialization complete
I: Sending test packet
I: CONSTLAT=0 (I think It's should 1 when enable)
D: TX FAILED EVENT

esb_ptx_2.zip