Module dma 

DMA driver.

This module provides a typed channel abstraction over the EDMA_0_TCD0 array and helpers for configuring the channel MUX. The driver supports higher-level async transfer APIs.

Architecture

The MCXA276 has 8 DMA channels (0-7), each with its own interrupt vector. Each channel has a Transfer Control Descriptor (TCD) that defines the transfer parameters.

Choosing the Right API

This module provides several API levels to match different use cases:

High-Level Async API (Recommended for Most Users)

Use the async methods when you want simple, safe DMA transfers:

Method	Description
DmaChannel::mem_to_mem()	Memory-to-memory copy
DmaChannel::memset()	Fill memory with a pattern
DmaChannel::write_to_peripheral()	Memory-to-peripheral (TX)
DmaChannel::read_from_peripheral()	Peripheral-to-memory (RX)

These return a Transfer future that can be .awaited:

let dma_ch = DmaChannel::new(p.DMA_CH0);
dma_ch.mem_to_mem(&src, &mut dst, TransferOptions::default()).await;

Scatter-Gather Builder (For Chained Transfers)

Use ScatterGatherBuilder for complex multi-segment transfers:

let mut builder = ScatterGatherBuilder::<u32>::new();
builder.add_transfer(&src1, &mut dst1);
builder.add_transfer(&src2, &mut dst2);

let transfer = builder.build(&dma_ch).unwrap();
transfer.await;

Structs

AnyChannel

Type-erased DMA channel peripheral.

DmaChannel

DMA channel driver.

InvalidParameters

An error that can occur if the parameters passed were invalid.

RingBuffer

A ring buffer for continuous DMA reception.

ScatterGatherBuilder

A builder for constructing scatter-gather DMA transfer chains.

ScatterGatherResult

A completed scatter-gather transfer result.

Transfer

An in-progress DMA transfer.

TransferErrorIter

Iterator to extract all TransferErrors using TransferErrors::into_iter.

TransferErrors

A collection of TransferError returned by any transfer.

TransferOptions

DMA transfer options.

Enums

Error

General DMA error types.

Priority

DMA transfer priority.

TransferError

An error that can be returned as the result of a failed transfer.

WordSize

DMA transfer data width.

Constants

DMA_MAX_TRANSFER_SIZE

Maximum bytes per DMA transfer (eDMA4 CITER/BITER are 15-bit fields).

Traits

Channel

Marker trait implemented by HAL peripheral tokens that map to a DMA0 channel backed by one EDMA_0_TCD0 TCD slot.

Word

Trait for word-sizes that are supported.