c3a580ee89
* Add TLS (https) support * Add NTP server * Clean up include path, add BearSSL headers * Allow 2 NTP servers, add ESP8266 compat define * Add MFLN SSL example, free/used/total heap getters * Enable stack thunking * Add tested SSL examples * Add BSSL_validation demo * Add Client Certificate example * Add RP2040 helper docs * Clean up doc errors, missing doc version info * Add WiFiClientSecure documentation * Add NTP docs Fixes #679
83 lines
2.8 KiB
ReStructuredText
83 lines
2.8 KiB
ReStructuredText
Multicore Processing
|
|
====================
|
|
|
|
The RP2040 chip has 2 cores that can run independently of each other, sharing
|
|
peripherals and memory with each other. Arduino code will normally execute
|
|
only on core 0, with the 2nd core sitting idle in a low power state.
|
|
|
|
By adding a ``setup1()`` and ``loop1()`` function to your sketch you can make
|
|
use of the second core. Anything called from within the ``setup1()`` or
|
|
``loop1()`` routines will execute on the second core.
|
|
|
|
``setup()`` and ``setup1()`` will be called at the same time, and the ``loop()``
|
|
or ``loop1()`` will be started as soon as the core's ``setup()`` completes (i.e.
|
|
not necessarily simultaneously!).
|
|
|
|
See the ``Multicore.ino`` example in the ``rp2040`` example directory for a
|
|
quick introduction.
|
|
|
|
Pausing Cores
|
|
-------------
|
|
|
|
Sometimes an application needs to pause the other core on chip (i.e. it is
|
|
writing to flash or needs to stop processing while some other event occurs).
|
|
|
|
void rp2040.idleOtherCore()
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Sends a message to stop the other core (i.e. when called from core 0 it
|
|
pauses core 1, and vice versa). Waits for the other core to acknowledge
|
|
before returning.
|
|
|
|
The other core will have its interrupts disabled and be busy-waiting in
|
|
an RAM-based routine, so flash and other peripherals can be accessed.
|
|
|
|
**NOTE** If you idle core 0 too long, then the USB port can become frozen.
|
|
This is because core 0 manages the USB and needs to service IRQs in a
|
|
timely manner (which it can't do when idled).
|
|
|
|
void rp2040.resumeOtherCore()
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Resumes processing in the other core, where it left off.
|
|
|
|
|
|
void rp2040.restartCore1()
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Hard resets Core1 from Core 0 and restarts its operation from ``setup1()``.
|
|
|
|
Communicating Between Cores
|
|
---------------------------
|
|
|
|
The RP2040 provides a hardware FIFO for communicating between cores, but it
|
|
is used exclusively for the idle/resume calls described above. Instead, please
|
|
use the following functions to access a software-managed, multicore safe
|
|
FIFO.
|
|
|
|
void rp2040.fifo.push(uint32_t)
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Pushes a value to the other core. Will block if the FIFO is full.
|
|
|
|
bool rp2040.fifo.push_nb(uint32_t)
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Pushes a value to the other core. If the FIFO is full, returns ``false``
|
|
immediately and doesn't block. If the push is successful, returns ``true``.
|
|
|
|
uint32_t rp2040.fifo.pop()
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Reads a value from this core's FIFO. Blocks until one is available.
|
|
|
|
bool rp2040.fifo.pop_nb(uint32_t \*dest)
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Reads a value from this core's FIFO and places it in dest. Will return
|
|
``true`` if successful, or ``false`` if the pop would block.
|
|
|
|
int rp2040.fifo.available()
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Returns the number of values available in this core's FIFO.
|