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  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="GUID-D089C2E9-1BE4-4B37-B8A8-21E5B2425E6C" xml:lang="en"><title>SDIO
Technology Guide</title><shortdesc>Provides information about the concepts and the uses of the SDIO
card.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<section id="GUID-075122CD-EA1E-4567-9D0F-5DFA548DA883">       <title>Purpose</title> 
     <p>The Secure Digital Input/Output (SDIO) protocol is based on the SD
memory card protocols. The SDIO bus enables high speed data transfers between
the host and a card. The SDIO consumes low power and is efficient for use
in mobile devices. SDIO cards like SD cards use star topology that have dedicated
command and data signals. The purpose of the SDIO APIs is to enable easy porting
of the Symbian SDIO services for a particular SDIO controller.</p> 
   </section>
<section id="GUID-57C125FF-4196-40D7-B1E5-DDA292076916"><title>Key concepts</title><ul>
<li><p><b>SDIO controller:</b></p> is the executable that manages access to
the SDIO card hardware interface and provides an API for class drivers to
access SDIO card functions.</li>
</ul><ul>
<li><p><b> Stack:</b></p>handles multiple requests simultaneously.  It internally
schedules the requests on to the bus and allocates the appropriate card to
transfer data accordingly.</li>
</ul><ul>
<li><p><b>Session:</b></p> sets up a session object to perform SDIO specific
command sequences.</li>
</ul><ul>
<li><p><b>Register interface:</b></p> allows single byte read/write operations
to a given register address together with the corresponding ones for multi-byte
access. </li>
</ul></section>
<section id="GUID-16D2B044-0E5A-4126-ADAC-B297C4B616F8"><title>Typical Uses</title><ul>
<li><p>Powering up stack containing a single SDIO Card.</p></li>
<li><p>Sending a command to PSL.</p></li>
<li><p>Acquiring new cards into the SDIO stack.</p></li>
<li><p>Configuring an SDIO card.</p></li>
</ul></section>
</conbody></concept>