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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-10C986FD-BD56-4F8E-87EC-7B890EFCDAC7" xml:lang="en"><title>DMA Chipset Configuration</title><shortdesc>Chipset configuration is performed entirely within the

    13 platform service implementation.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>The DMA controller chipset has multiple DMA channels that can be

    15 configured for different DMA transfers. Drivers generally initialize

    16 and open the required DMA channel and use this channel to do the DMA

    17 transfers. </p>

    18 <p>For some peripherals, such as the Camera and the Display controller,

    19 there can be dedicated DMA channels that cannot be configured for

    20 DMA transfers by other peripherals. </p>

    21 <p>To configure the channels and other features of the chipset, you

    22 may need to write code. This code should be executed prior to the

    23 DMA channels being used for the first time, or to configure dynamically-allocated

    24 channels.</p>

    25 <p>This requires chipset specific code which is beyond the scope of

    26 this documentation. Please refer to your chipset's datasheet and any

    27 accompanying documentation for details on how to perform any required

    28 chipset configuration.</p>

    29 <p><note>If you need to perform chipset configuration after the device

    30 driver has loaded, there is an <xref href="GUID-93A3F01A-3489-37E5-921C-5EA5228545AA.dita"><apiname>Extension()</apiname></xref> function.

    31 This function passes chipset specific code or instructions from the

    32 client to the platform service implementation. Implementation of the <xref href="GUID-93A3F01A-3489-37E5-921C-5EA5228545AA.dita"><apiname>Extension()</apiname></xref> API is platform specific and is not covered

    33 further in this documentation.</note></p>

    34 </conbody></concept>