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    10 <!DOCTYPE concept

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

    12 <concept id="GUID-8798F896-E0CB-4B9B-8F88-3C8B58574213" xml:lang="en"><title>The

    13 Physical Channel</title><shortdesc>This document describes how a logical device communicates with

    14 a physical device over a physical channel.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    15 <section id="GUID-A759AA8D-945A-4150-822A-C22DFAE8F5C9">           <p>The

    16 physical channel defines the interface between the logical device and the

    17 physical device. Typically, this interface is different for each device family

    18 and, therefore, the device driver framework does not require a particular

    19 type of interface. The only requirement is that the physical channel class

    20 is derived from <xref href="GUID-4FCB6127-84F3-38F6-8AD2-FC3B94D67DA3.dita"><apiname>DBase</apiname></xref>. It is up to the driver writer to

    21 define the physical channel class. </p> <fig id="GUID-8C470617-1743-546F-A0A4-A20B1480539D">

    22 <title>                 Device driver physical channel classes           

    23    </title>

    24 <image href="GUID-F8A32666-5003-5B14-A700-C6E6388D2D38_d0e63938_href.png" placement="inline"/>

    25 </fig>     </section>

    26 </conbody></concept>