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Last updated: 27 Aug 2020
The Freedom-K64F is an ultra-low-cost development platform for Kinetis K64, K63, and K24 MCUs.

Tickless mode not enabled by default

Topic last updated 30 Aug 2019, by Leszek Grzegorek. 2 replies
Leszek Grzegorek
01 Aug 2019

Looking at the power consumption and possibility to enter the deep sleep mode (VLPS strictly speaking) is possible only when low power ticker is implemented (DEVICE_LPTICKER) and MBED_TICKLESS is defined. Otherwise, without MBED_TICKLESS the default_idle_hook() will never allow entering deep sleep as it sets deep sleep lock before call to sleep().

FRDM-K64F defines DEVICE_LPTICKER but not MBED_TICKLESS. Could someone tell me please why MBED_TICKLESS is not defined by default in targets.json for that board ? Are there any shortcomings of doing this ? Any answer is highly appreciated.

Desmond Chen
29 Aug 2019

Hi Leszek,

Which version of Mbed OS are you using? There are indeed some issues of tickless on k64f so we didn't enable it by default, but after this PR we already enable it. https://github.com/ARMmbed/mbed-os/pull/10796

We recommend you to update your Mbed OS to latest version (which is 5.13.4 now), you will be able to see MBED_TICKLESS under target K64F. https://github.com/ARMmbed/mbed-os/blob/1bf6b20df9d3cd5f29f001ffc6f0d0fcbbb96118/targets/targets.json#L1503

Thanks, Desmond

Leszek Grzegorek
30 Aug 2019

Hi Desmond,

Thank you for your response. Last time I checked it on 5.12.x, so everything is clear now :) Happy to see this merged !

Best regards, Leszek