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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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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 |
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13 platform service implementation.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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14 <p>The DMA controller chipset has multiple DMA channels that can be |
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15 configured for different DMA transfers. Drivers generally initialize |
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16 and open the required DMA channel and use this channel to do the DMA |
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17 transfers. </p> |
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18 <p>For some peripherals, such as the Camera and the Display controller, |
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19 there can be dedicated DMA channels that cannot be configured for |
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20 DMA transfers by other peripherals. </p> |
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21 <p>To configure the channels and other features of the chipset, you |
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22 may need to write code. This code should be executed prior to the |
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23 DMA channels being used for the first time, or to configure dynamically-allocated |
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24 channels.</p> |
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25 <p>This requires chipset specific code which is beyond the scope of |
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26 this documentation. Please refer to your chipset's datasheet and any |
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27 accompanying documentation for details on how to perform any required |
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28 chipset configuration.</p> |
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29 <p><note>If you need to perform chipset configuration after the device |
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30 driver has loaded, there is an <xref href="GUID-93A3F01A-3489-37E5-921C-5EA5228545AA.dita"><apiname>Extension()</apiname></xref> function. |
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31 This function passes chipset specific code or instructions from the |
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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 |
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33 further in this documentation.</note></p> |
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34 </conbody></concept> |