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35 lines
1.2 KiB
ReStructuredText
35 lines
1.2 KiB
ReStructuredText
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.. _module-pw_chrono_threadx:
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-=---------------
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pw_chrono_threadx
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-----------------
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``pw_chrono_threadx`` is a collection of ``pw_chrono`` backends that are
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implemented using ThreadX.
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.. warning::
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This module is under construction, not ready for use, and the documentation
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is incomplete.
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SystemClock backend
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-------------------
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The ThreadX based ``system_clock`` backend implements the
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``pw_chrono:system_clock`` facade by using ``tx_time_get()``. Before the global
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singleton SystemClock's SpinLock is constructed the raw result is returned,
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after the overflows are managed in a thread and IRQ safe manner to produce a
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signed 64 bit timestamp.
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The ``SystemClock::now()`` must be used more than once per overflow of the
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native ThreadX ``tx_time_get()`` overflow. Note that this duration may vary if
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``tx_time_set()`` is used.
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.. warning::
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Note that this is not compatible with TX_NO_TIMER as this disables
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``tx_time_get()``.
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Build targets
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-------------
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The GN build for ``pw_chrono_threadx`` has one target: ``system_clock``.
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The ``system_clock`` target provides the
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``pw_chrono_backend/system_clock_config.h`` and ``pw_chrono_threadx/config.h``
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headers and the backend for the ``pw_chrono:system_clock``.
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