How to change SYS_CLOCK_TICKS_PER_SEC from 1000 to 168000 at runtime?

[NamrataGagare-eaton]

Background Context:
I'm working on an application using STM32H743ZI and STM32U575ZI_Q with Zephyr RTOS v3.7.1 running at 168MHz. I need to dynamically change the system tick frequency from the default 1000 to 168000 at runtime.

Current Setup:
// prj.conf
CONFIG_SYS_CLOCK_TICKS_PER_SEC=1000

Desired Runtime Change:
// Runtime target
SYS_CLOCK_TICKS_PER_SEC = 168000

Primary Questions:
Is runtime tick frequency change supported?

• Can SYS_CLOCK_TICKS_PER_SEC be modified after system initialization?
• Are there Zephyr APIs to change the system tick rate dynamically?

Any experience, warnings, or alternative approaches would be greatly appreciated!

Thanks,
Namrata Gagare

[yvesll]

Zephyr does not support modify system clock tick frequency at run time. It shall be certain value at compile stage and kernel timer is highly depended on it. You can use an alternative timer supported by your platform under drivers/timer.