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<!DOCTYPE concept
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="GUID-C649DB97-F138-4C90-B177-16590F2E3F19" xml:lang="en"><title>DMA
Channels</title><shortdesc>This document describes how device drivers use DMA channels.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>The DMAC has different DMA channels that can be configured for different
DMA transfers. Drivers generally initialise and open the required DMA channel
and use this channel to do the DMA transfers. For some peripherals, such as
the Camera and the Display controller, there can be dedicated DMA channels
that cannot be configured for DMA transfers by other peripherals. </p>
<p>Initialization and opening of DMA channels is done using the interface <xref href="GUID-83882548-FAC5-3EFF-92ED-14D1D9A85D37.dita"><apiname>TDmaChannel</apiname></xref>. </p>
<note>This class is designed only for single-thread client access. When used
by multi-threaded clients, synchronisation mechanisms should be provided by
the driver. </note>
<p>DMA channels must be opened before use and closed after completion of DMA
operations, as shown below. </p>
</conbody></concept>