| .. _module-pw_chrono_embos: |
| |
| --------------- |
| pw_chrono_embos |
| --------------- |
| ``pw_chrono_embos`` is a collection of ``pw_chrono`` backends that are |
| implemented using embOS v4 for 32bit targets. |
| |
| .. warning:: |
| This module is under construction, not ready for use, and the documentation |
| is incomplete. |
| |
| SystemClock backend |
| ------------------- |
| The embOS based ``system_clock`` backend implements the |
| ``pw_chrono:system_clock`` facade by using ``OS_GetTime32()``. Before the global |
| singleton SystemClock's SpinLock is constructed the raw result is returned, |
| after the overflows are managed in a thread and IRQ safe manner to produce a |
| signed 64 bit timestamp. Note that this does NOT use ``OS_GetTime_us64()`` which |
| is not always available, this could be considered for a future alternative |
| backend for the SystemClock. |
| |
| The ``SystemClock::now()`` must be used more than once per overflow of the |
| native embOS ``OS_GetTime32()`` overflow. Note that this duration may |
| vary if ``OS_SUPPORT_TICKLESS`` is used. |
| |
| Build targets |
| ------------- |
| The GN build for ``pw_chrono_embos`` has one target: ``system_clock``. |
| The ``system_clock`` target provides the |
| ``pw_chrono_backend/system_clock_config.h`` and ``pw_chrono_embos/config.h`` |
| headers and the backend for the ``pw_chrono:system_clock``. |
