95 lines
2.3 KiB
ReStructuredText
95 lines
2.3 KiB
ReStructuredText
.. currentmodule:: rp2
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.. _rp2.PIO:
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class PIO -- advanced PIO usage
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===============================
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The :class:`PIO` class gives access to an instance of the RP2040's PIO
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(programmable I/O) interface.
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The preferred way to interact with PIO is using :class:`rp2.StateMachine`, the
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PIO class is for advanced use.
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For assembling PIO programs, see :func:`rp2.asm_pio`.
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Constructors
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------------
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.. class:: PIO(id)
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Gets the PIO instance numbered *id*. The RP2040 has two PIO instances,
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numbered 0 and 1.
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Raises a ``ValueError`` if any other argument is provided.
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Methods
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-------
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.. method:: PIO.add_program(program)
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Add the *program* to the instruction memory of this PIO instance.
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The amount of memory available for programs on each PIO instance is
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limited. If there isn't enough space left in the PIO's program memory
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this method will raise ``OSError(ENOMEM)``.
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.. method:: PIO.remove_program([program])
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Remove *program* from the instruction memory of this PIO instance.
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If no program is provided, it removes all programs.
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It is not an error to remove a program which has already been removed.
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.. method:: PIO.state_machine(id, [program, ...])
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Gets the state machine numbered *id*. On the RP2040, each PIO instance has
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four state machines, numbered 0 to 3.
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Optionally initialize it with a *program*: see `StateMachine.init`.
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>>> rp2.PIO(1).state_machine(3)
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StateMachine(7)
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.. method:: PIO.irq(handler=None, trigger=IRQ_SM0|IRQ_SM1|IRQ_SM2|IRQ_SM3, hard=False)
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Returns the IRQ object for this PIO instance.
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MicroPython only uses IRQ 0 on each PIO instance. IRQ 1 is not available.
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Optionally configure it.
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Constants
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---------
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.. data:: PIO.IN_LOW
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PIO.IN_HIGH
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PIO.OUT_LOW
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PIO.OUT_HIGH
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These constants are used for the *out_init*, *set_init*, and *sideset_init*
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arguments to `asm_pio`.
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.. data:: PIO.SHIFT_LEFT
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PIO.SHIFT_RIGHT
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These constants are used for the *in_shiftdir* and *out_shiftdir* arguments
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to `asm_pio` or `StateMachine.init`.
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.. data:: PIO.JOIN_NONE
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PIO.JOIN_TX
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PIO.JOIN_RX
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These constants are used for the *fifo_join* argument to `asm_pio`.
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.. data:: PIO.IRQ_SM0
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PIO.IRQ_SM1
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PIO.IRQ_SM2
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PIO.IRQ_SM3
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These constants are used for the *trigger* argument to `PIO.irq`.
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