Struct embassy_stm32::dma::ReadableRingBuffer

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pub struct ReadableRingBuffer<'a, C: Channel, W: Word> { /* private fields */ }
Expand description

Ringbuffer for reading data using DMA circular mode.

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impl<'a, C: Channel, W: Word> ReadableRingBuffer<'a, C, W>

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pub unsafe fn new( channel: impl Peripheral<P = C> + 'a, _request: Request, peri_addr: *mut W, buffer: &'a mut [W], _options: TransferOptions ) -> Self

Create a new ring buffer.

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pub fn start(&mut self)

Start the ring buffer operation.

You must call this after creating it for it to work.

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pub fn clear(&mut self)

Clear all data in the ring buffer.

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pub fn read(&mut self, buf: &mut [W]) -> Result<(usize, usize), OverrunError>

Read elements from the ring buffer Return a tuple of the length read and the length remaining in the buffer If not all of the elements were read, then there will be some elements in the buffer remaining The length remaining is the capacity, ring_buf.len(), less the elements remaining after the read OverrunError is returned if the portion to be read was overwritten by the DMA controller.

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pub async fn read_exact( &mut self, buffer: &mut [W] ) -> Result<usize, OverrunError>

Read an exact number of elements from the ringbuffer.

Returns the remaining number of elements available for immediate reading. OverrunError is returned if the portion to be read was overwritten by the DMA controller.

Async/Wake Behavior: The underlying DMA peripheral only can wake us when its buffer pointer has reached the halfway point, and when it wraps around. This means that when called with a buffer of length ‘M’, when this ring buffer was created with a buffer of size ‘N’:

  • If M equals N/2 or N/2 divides evenly into M, this function will return every N/2 elements read on the DMA source.
  • Otherwise, this function may need up to N/2 extra elements to arrive before returning.
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pub const fn capacity(&self) -> usize

The capacity of the ringbuffer.

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pub fn set_waker(&mut self, waker: &Waker)

Set a waker to be woken when at least one byte is received.

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pub fn request_stop(&mut self)

Request DMA to stop.

This doesn’t immediately stop the transfer, you have to wait until is_running returns false.

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pub fn is_running(&mut self) -> bool

Return whether DMA is still running.

If this returns false, it can be because either the transfer finished, or it was requested to stop early with request_stop.

Trait Implementations§

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impl<'a, C: Channel, W: Word> Drop for ReadableRingBuffer<'a, C, W>

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fn drop(&mut self)

Executes the destructor for this type. Read more

Auto Trait Implementations§

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impl<'a, C, W> Freeze for ReadableRingBuffer<'a, C, W>
where C: Freeze,

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impl<'a, C, W> RefUnwindSafe for ReadableRingBuffer<'a, C, W>

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impl<'a, C, W> Send for ReadableRingBuffer<'a, C, W>
where C: Send, W: Send,

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impl<'a, C, W> Sync for ReadableRingBuffer<'a, C, W>
where C: Sync, W: Sync,

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impl<'a, C, W> Unpin for ReadableRingBuffer<'a, C, W>
where C: Unpin,

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impl<'a, C, W> !UnwindSafe for ReadableRingBuffer<'a, C, W>

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.