# Low Power Support - My FreeRTOSConfig.h dosn't have "configUSE\_TICKLESS\_IDLE", I can just define one, right?

**URL:** <https://forums.freertos.org/t/low-power-support-my-freertosconfig-h-dosnt-have-configuse-tickless-idle-i-can-just-define-one-right/10678>\
**Category:** Kernel\
**Created:** [September 15, 2020, 11:52pm UTC](https://forums.freertos.org/t/low-power-support-my-freertosconfig-h-dosnt-have-configuse-tickless-idle-i-can-just-define-one-right/10678 "2020-09-15T23:52:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Yuki2983](https://avatars.discourse-cdn.com/v4/letter/y/ccd318/32.png) [@Yuki2983](https://forums.freertos.org/u/Yuki2983)\
**Post date:** [September 15, 2020, 11:52pm UTC](https://forums.freertos.org/t/low-power-support-my-freertosconfig-h-dosnt-have-configuse-tickless-idle-i-can-just-define-one-right/10678/1 "2020-09-15T23:52:45Z")

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My platform: STM32WB55x device, 512K Flash, 512K Ram, 32Mhz main freq., M4F core.

Various documents still available on the official site, like this:

> **[Tickless Low power features in FreeRTOS](https://www.freertos.org/low-power-tickless-rtos.html)**
>
> Low power tickless features in FreeRTOS

Mentions defining “configUSE\_TICKLESS\_IDLE” to 1 or 2 in FreeRTOSConfig.h

I looked up the port I’m using but there is no configUSE\_TICKLESS\_IDLE in my “FreeRTOSConfig.h”.

However in other part of the FreeRTOS source code there most definitely is an implementation for “portSUPPRESS\_TICKS\_AND\_SLEEP()”.

My question is I could simple add a line of

#define configUSE\_TICKLESS\_IDLE 1

in the FreeRTOSConfig.h file right?

Or things are much more complicated than this and I’m messing up different versions here? I’ve added that definition and complied and it passed.

Can anyone please shed any light? I want to be 100% sure.

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**Author:** ![jefftenney](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/jefftenney/32/1314_2.png) [@jefftenney](https://forums.freertos.org/u/jefftenney)\
**Post date:** [September 16, 2020, 5:08am UTC](https://forums.freertos.org/t/low-power-support-my-freertosconfig-h-dosnt-have-configuse-tickless-idle-i-can-just-define-one-right/10678/2 "2020-09-16T05:08:35Z")

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Yes, you can add that #define to FreeRTOSConfig.h and you’ll get tickless idle. If you have a debugger, you can put breakpoints in vPortSuppressTicksAndSleep() and see that the feature is active and working.