rmt: support REF_TICK as channel clock source

Closes https://github.com/espressif/esp-idf/pull/3952
This commit is contained in:
morris
2020-02-14 14:33:07 +08:00
parent 3c43264f83
commit 0e4d82bc55
7 changed files with 82 additions and 42 deletions

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@@ -113,7 +113,11 @@ Common Parameters
* The RMT **operation mode** - whether this channel is used to transmit or receive data, selected by setting a **rmt_mode** members to one of the values from :cpp:type:`rmt_mode_t`.
* What is the **pin number** to transmit or receive RMT signals, selected by setting **gpio_num**.
* How many **memory blocks** will be used by the channel, set with **mem_block_num**.
* A **clock divider**, that will determine the range of pulse length generated by the RMT transmitter or discriminated by the receiver. Selected by setting **clk_div** to a value within [1 .. 255] range. The RMT source clock is typically APB CLK, 80Mhz by default.
* Extra miscellaneous parameters for the channel can be set in the **flags**.
* When **RMT_CHANNEL_FLAGS_ALWAYS_ON** is set, RMT channel will take REF_TICK as source clock. The benefit is, RMT channel can continue work even when APB clock is changing. See :doc:`power_management <../system/power_management>` for more information.
* A **clock divider**, that will determine the range of pulse length generated by the RMT transmitter or discriminated by the receiver. Selected by setting **clk_div** to a value within [1 .. 255] range. The RMT source clock is typically APB CLK, 80Mhz by default. But when **RMT_CHANNEL_FLAGS_ALWAYS_ON** is set in **flags**, RMT source clock is changed to REF_TICK.
.. note::