<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

<!-- This component and the accompanying materials are made available under the terms of the License 

"Eclipse Public License v1.0" which accompanies this distribution, 

and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

<!-- Initial Contributors:

    Nokia Corporation - initial contribution.

Contributors: 

-->

<!DOCTYPE concept

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

<concept id="GUID-48AEF60B-D2B6-55B5-96FD-55C1F1868A3F" xml:lang="en"><title>GPIO

Implementation Guide</title><shortdesc>This document tells you things you need to know to produce a platform

specific implementation of the Symbian platform generic GPIO interface. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-DF9D655C-161E-5EC0-815C-4AD3483ED290"><title>Required background</title> <p>Before

you start, you must: </p> <ul>

<li id="GUID-210FC785-9589-5E8B-9A10-115359521C3D"><p>understand platform

implementation, </p> </li>

<li id="GUID-9DFA66B1-316A-5D23-8DEB-CC82EFA4E1A9"><p>understand GPIO concepts

and terminology, </p> </li>

<li id="GUID-5B26CDEE-B6F4-5A19-A675-7614159F7786"><p>know the architecture

of the platform on which you are implementing, and </p> </li>

<li id="GUID-680844F2-25CC-5E95-B1E0-943D5E119555"><p>understand the C++ signature

of the functions you are implementing. </p> </li>

</ul> </section>

<section id="GUID-3657983A-8801-4F51-B996-70D942DBD17B"><title>Introduction</title> <p>You can provide support for GPIO hardware

in a board support package by implementing the interface that Symbian platform

defines in the GPIO class. To provide a consistent interface to clients of

the GPIO class, your implementation must return certain error codes in certain

specified conditions. The details of the functions, conditions and associated

required return values are described below. How your implementation of the

functions communicates with your GPIO hardware will be specific to the hardware

you are using. </p> </section>

<section id="GUID-37F49486-8821-4CED-BC19-5818D890CD85"><title>Procedure</title><p>Implement each function of class <xref href="GUID-C93C53D3-2BE8-36AE-83B8-4CDB4195649B.dita"><apiname>GPIO</apiname></xref> with

a return value of </p> <ul id="GUID-B39F7C57-765D-54AF-8296-4A9C6EF8D75E">

<li id="GUID-9E22A75B-E0E0-54D8-B4BB-DCF0E52C8DAD"><p> <xref href="GUID-C93C53D3-2BE8-36AE-83B8-4CDB4195649B.dita"><apiname>KErrArgument</apiname></xref>, </p> </li>

<li id="GUID-735EE673-F24B-5ACC-AF9D-DD3437D763D9"><p> <xref href="GUID-C93C53D3-2BE8-36AE-83B8-4CDB4195649B.dita"><apiname>KErrNone</apiname></xref>, </p> </li>

<li id="GUID-EA824100-5317-599D-9270-A93EDF1A6275"><p> <xref href="GUID-C93C53D3-2BE8-36AE-83B8-4CDB4195649B.dita"><apiname>KErrNotSupported</apiname></xref>  </p> </li>

</ul><p>and other return values as specified for particular functions.</p></section>

<section id="GUID-3D5B6289-7C6D-48BC-9A56-500DD10CD64C"><title>Returning KErrArgument</title> <p>     Implement each function

of class <xref href="GUID-C93C53D3-2BE8-36AE-83B8-4CDB4195649B.dita"><apiname>GPIO</apiname></xref> with a return value of <xref href="GUID-0BEA3647-7888-3612-A2D3-7E27AC405E29.dita"><apiname>KErrArgument</apiname></xref>.

  </p> <p>     The first argument of every function is <codeph>aId</codeph> and

represents the ID of a pin. If the passed-in ID is invalid, the function should

return <xref href="GUID-0BEA3647-7888-3612-A2D3-7E27AC405E29.dita"><apiname>KErrArgument</apiname></xref> without further activity.   </p>  </section>

<section id="GUID-C8665E28-9AA5-4363-9BF1-5AA1ABA5B598"><title>Pin mode functions</title> <p>Implement the pin mode functions.

 </p> <ul>

<li><p>  Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> for each value of the 

        enumeration <xref href="GUID-BA2AE083-DB8D-327F-85FE-EAB765DAF360.dita"><apiname>TGpioMode</apiname></xref>.  </p> <ul>

<li><p>Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> with <codeph>aMode</codeph> == <xref href="GUID-500F8E1C-714A-3942-B584-39C44FAF6873.dita"><apiname>EEnabled</apiname></xref> and

return value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.</p> <p> Enable the pin for GPIO.

Make any functionality other than  GPIO unavailable. Enable the module if

it is not already enabled. This  typically requires power and clocks to be

supplied to the module. </p> </li>

<li><p> Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> with  <codeph>aMode</codeph> == <xref href="GUID-4EC4F5AE-557D-3249-A3D3-31653DECD706.dita"><apiname>EDisabled</apiname></xref> and

return value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>. </p> <p> Disable the pin for GPIO.

Disable the module for GPIO. Only a  all to <xref href="GUID-AF952FD7-0B2F-3985-9B1E-02E87734AC6E.dita"><apiname>SetPinMode</apiname></xref> with <xref href="GUID-1D258A78-63B0-3AAF-8359-CB1C62883F38.dita"><apiname>aMode</apiname></xref> ==

 <xref href="GUID-500F8E1C-714A-3942-B584-39C44FAF6873.dita"><apiname>EEnabled</apiname></xref> should return the pin to the enabled state. If

 the pin is enabled for another function, that fact is irrelevant.   </p> </li>

<li><p>                Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> with    

           <codeph>aMode</codeph> == <xref href="GUID-89A388CF-9DF5-3CD3-AD5E-D2EE98B7F97E.dita"><apiname>EIdle</apiname></xref> and return value

               <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p>        

       Only implement this if the platform supports the idle state.      

       </p> <p>                When the pin is set to the idle state, the

implementation                should also attempt to move the module to the

idle state.              </p> </li>

<li><p>                Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> with return

value                <xref href="GUID-51298FCE-7857-39F8-BFAB-49AF5556D0CC.dita"><apiname>KErrNotReady</apiname></xref>.              </p> <p> 

              Return <xref href="GUID-51298FCE-7857-39F8-BFAB-49AF5556D0CC.dita"><apiname>KErrNotReady</apiname></xref> when a pin which has

               requested a return to the idle state is not ready to do so.

             </p> </li>

<li><p>                Implement <xref href="GUID-47A5FEB0-144E-398B-A3B0-8A524A59B7F2.dita"><apiname>SetPinMode()</apiname></xref> with return

value                <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.              </p> <p> 

              Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin is   

            not available for GPIO because it has been assigned an alternative

function and                also where <xref href="GUID-89A388CF-9DF5-3CD3-AD5E-D2EE98B7F97E.dita"><apiname>EIdle</apiname></xref> is passed

and the platform does not                support an idle state.          

   </p> </li>

</ul> </li>

<li><p>          Implement <xref href="GUID-44CFE638-7ECD-369F-8D06-E2970DF078B7.dita"><apiname>GetPinMode()</apiname></xref> for each value

of the          enumeration <xref href="GUID-BA2AE083-DB8D-327F-85FE-EAB765DAF360.dita"><apiname>TGpioMode</apiname></xref>.         </p> </li>

<li><p>             Implement <xref href="GUID-44CFE638-7ECD-369F-8D06-E2970DF078B7.dita"><apiname>GetPinMode()</apiname></xref> with       

     <codeph>aMode</codeph> containing <xref href="GUID-500F8E1C-714A-3942-B584-39C44FAF6873.dita"><apiname>EEnabled</apiname></xref> and return

value             <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p>        

    Verify that the pin is already enabled for GPIO and able to          

  work according to its configuration. Set <xref href="GUID-1D258A78-63B0-3AAF-8359-CB1C62883F38.dita"><apiname>aMode</apiname></xref> to   

         <xref href="GUID-500F8E1C-714A-3942-B584-39C44FAF6873.dita"><apiname>EEnabled</apiname></xref>.           </p> </li>

<li><p>             Implement <xref href="GUID-44CFE638-7ECD-369F-8D06-E2970DF078B7.dita"><apiname>GetPinMode()</apiname></xref> with       

     <codeph>aMode</codeph> containing <xref href="GUID-4EC4F5AE-557D-3249-A3D3-31653DECD706.dita"><apiname>EDisabled</apiname></xref> and return

value             <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p>        

    Verify that the module is already disabled and the pin cannot        

    be used for GPIO. If the pin is enabled for another function, that fact

is             irrelevant.           </p> </li>

<li><p>             Implement <xref href="GUID-44CFE638-7ECD-369F-8D06-E2970DF078B7.dita"><apiname>GetPinMode()</apiname></xref> with       

     <codeph>aMode</codeph> containing <xref href="GUID-89A388CF-9DF5-3CD3-AD5E-D2EE98B7F97E.dita"><apiname>EIdle</apiname></xref> and return

value             <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p>        

    Only implement this if the platform supports the idle state.         

 </p> <p>             Verify that the module is already in an idle state.

          </p> </li>

<li><p>             Implement <xref href="GUID-44CFE638-7ECD-369F-8D06-E2970DF078B7.dita"><apiname>GetPinMode()</apiname></xref> with return

value             <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.           </p> <p> 

           Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the platform    

        does not support reading the pin mode.           </p> </li>

</ul></section>

<section id="GUID-3DA1E4AC-BAE0-469E-8A5D-72E292A533C1"><title>Pin direction functions</title><p>Implement the pin direction

functions.</p> <ul>

<li><p>          Implement <xref href="GUID-38FAAC57-13CF-390F-AE05-8D2B9E092450.dita"><apiname>SetPinDirection()</apiname></xref> for each value

         of the enumeration <xref href="GUID-2F6DB4C0-D198-39A8-B990-EF1D5B9B5901.dita"><apiname>TGpioDirection</apiname></xref>.</p><ul>

<li><p>             Implement <xref href="GUID-38FAAC57-13CF-390F-AE05-8D2B9E092450.dita"><apiname>SetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> == <xref href="GUID-EC5870C2-5C3E-3DFB-9349-85AAF1A0AE58.dita"><apiname>EInput</apiname></xref> and return

value             <codeph>KErrNone.</codeph>           </p> <p>          

  Set the pin to behave as an input binary signal.           </p> </li>

<li><p>             Implement <xref href="GUID-38FAAC57-13CF-390F-AE05-8D2B9E092450.dita"><apiname>SetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> == <xref href="GUID-8E81439B-6FB5-3EEC-BC36-F3B70217FA8D.dita"><apiname>EOutput</apiname></xref> and return

value             <codeph>KErrNone.</codeph>           </p> <p>          

  Set the pin to behave as an output binary signal.           </p> </li>

<li><p>             Implement <xref href="GUID-38FAAC57-13CF-390F-AE05-8D2B9E092450.dita"><apiname>SetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> == <xref href="GUID-2AEEC0C1-CF80-3C1D-B24B-17178ACA6AB4.dita"><apiname>ETriStated</apiname></xref> and

return value             <codeph>KErrNone.</codeph>           </p> <p>   

         Set the pin to be in a quiescent state (also called floating or 

           deactivated).           </p> <p>             Only implement this

if the platform supports the quiescent             state. The physical state

of the pin will be determined by the drive on the             line.      

    </p> </li>

<li><p>             Implement <xref href="GUID-38FAAC57-13CF-390F-AE05-8D2B9E092450.dita"><apiname>SetPinDirection()</apiname></xref> with return

            value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.           </p> <p> 

           Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin cannot  

          operate in the direction specified, for instance if             <xref href="GUID-2AEEC0C1-CF80-3C1D-B24B-17178ACA6AB4.dita"><apiname>ETriStated</apiname></xref> has

been passed and the platform does not             support the quiescent state.

          </p> </li>

</ul></li>

<li><p>          Implement <xref href="GUID-062A11F7-123D-334C-A082-F21DB9A9EE32.dita"><apiname>GetPinDirection()</apiname></xref> for each value

         of the enumeration <xref href="GUID-2F6DB4C0-D198-39A8-B990-EF1D5B9B5901.dita"><apiname>TGpioDirection</apiname></xref>.         </p> <ul>

<li><p>             Implement <xref href="GUID-062A11F7-123D-334C-A082-F21DB9A9EE32.dita"><apiname>GetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> containing <xref href="GUID-EC5870C2-5C3E-3DFB-9349-85AAF1A0AE58.dita"><apiname>EInput</apiname></xref> and

return value             <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p> 

           Verify that the pin is behaving as a binary input signal. Set 

           <xref href="GUID-221FF753-F089-399C-BD67-A693E68AB727.dita"><apiname>aDirection</apiname></xref> to <xref href="GUID-EC5870C2-5C3E-3DFB-9349-85AAF1A0AE58.dita"><apiname>EInput</apiname></xref>    

      </p> </li>

<li><p>             Implement <xref href="GUID-062A11F7-123D-334C-A082-F21DB9A9EE32.dita"><apiname>GetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> containing <xref href="GUID-8E81439B-6FB5-3EEC-BC36-F3B70217FA8D.dita"><apiname>EOutput</apiname></xref> and

return             value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p> 

           Verify that the pin is behaving as a binary output signal. Set

            <codeph>aDirection</codeph> to <xref href="GUID-EC5870C2-5C3E-3DFB-9349-85AAF1A0AE58.dita"><apiname>EInput</apiname></xref>     

     </p> </li>

<li><p>             Implement <xref href="GUID-062A11F7-123D-334C-A082-F21DB9A9EE32.dita"><apiname>GetPinDirection()</apiname></xref> with  

          <codeph>aDirection</codeph> containing <xref href="GUID-2AEEC0C1-CF80-3C1D-B24B-17178ACA6AB4.dita"><apiname>ETriStated</apiname></xref> and

return             value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p> 

           Verify that the pin is in the quiescent state. Set             <codeph>aDirection</codeph> to <xref href="GUID-2AEEC0C1-CF80-3C1D-B24B-17178ACA6AB4.dita"><apiname>ETriStated</apiname></xref> 

         </p> </li>

<li><p>             Implement <xref href="GUID-062A11F7-123D-334C-A082-F21DB9A9EE32.dita"><apiname>GetPinDirection()</apiname></xref> with return

            value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.           </p> <p> 

           Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if reading the pin 

           direction is not supported.           </p> </li>

</ul></li>

</ul> </section>

<section id="GUID-35D80FC2-4DBF-4FF2-ACB4-409020651F86"><title>Pin bias functions</title> <p>     Implement the pin bias

functions.  </p> <ul>

<li><p>          Implement <xref href="GUID-2179ABA4-EF54-31B4-876D-35DE3AED4486.dita"><apiname>SetPinBias()</apiname></xref> for each value

of the          enumeration <xref href="GUID-58D2511D-99F1-361B-875C-0A0C32775A3F.dita"><apiname>TGpioBias</apiname></xref>.        </p>  <p> 

        Only implement this function to return          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> if

the pin has a programmable device to stabilise          its electric state.

Otherwise just implement it with return value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.

        </p><ul>

<li><p>                Implement <xref href="GUID-2179ABA4-EF54-31B4-876D-35DE3AED4486.dita"><apiname>SetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> containing <xref href="GUID-41EC1BCD-EEE6-301F-84F5-5CED9F444991.dita"><apiname>ENoDrive</apiname></xref> and

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>. </p><p>         

                  Disable any resistor or weak drive forcing the pin to a

               default electrical state.              </p> </li>

<li><p>                Implement <xref href="GUID-2179ABA4-EF54-31B4-876D-35DE3AED4486.dita"><apiname>SetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> == <xref href="GUID-94DC7B4C-A782-3881-AC16-D982F206057A.dita"><apiname>EPullDown</apiname></xref> and return

value                .<xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Cause the pin to default to its low electrical state by    

           pull-down resistor, weak drive or other means.              </p> </li>

<li><p>                Implement <xref href="GUID-2179ABA4-EF54-31B4-876D-35DE3AED4486.dita"><apiname>SetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> == <xref href="GUID-EFC660F1-A375-304B-9866-C937D2A36AD9.dita"><apiname>EPullUp</apiname></xref> and return

value                .<xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Cause the pin to default to its high electrical state by   

            pull-down resistor, weak drive or other means.              </p> </li>

<li><p>                Implement <xref href="GUID-2179ABA4-EF54-31B4-876D-35DE3AED4486.dita"><apiname>SetPinBias()</apiname></xref> with return

value                <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.              </p> <p> 

              Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does 

              not support setting the drive.              </p> </li>

</ul> </li>

<li><p>          Implement <xref href="GUID-727E0B20-32AF-3CBE-B0AC-6381C16955F1.dita"><apiname>GetPinBias()</apiname></xref> for each value

of the          enumeration <xref href="GUID-58D2511D-99F1-361B-875C-0A0C32775A3F.dita"><apiname>TGpioBias</apiname></xref>.         </p> <p> 

        Only implement this function to return          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref> if

the pin has a programmable device to stabilise          its electric state.

Otherwise just implement it with return value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.

        </p> <ul>

<li><p>                Implement <xref href="GUID-727E0B20-32AF-3CBE-B0AC-6381C16955F1.dita"><apiname>GetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> containing <xref href="GUID-41EC1BCD-EEE6-301F-84F5-5CED9F444991.dita"><apiname>ENoDrive</apiname></xref> and

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Verify that any stabilising device on the pin has been     

          disabled. Set <codeph>aBias</codeph> to <xref href="GUID-41EC1BCD-EEE6-301F-84F5-5CED9F444991.dita"><apiname>ENoDrive</apiname></xref>.

             </p> </li>

<li><p>                Implement <xref href="GUID-727E0B20-32AF-3CBE-B0AC-6381C16955F1.dita"><apiname>GetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> containing <xref href="GUID-94DC7B4C-A782-3881-AC16-D982F206057A.dita"><apiname>EPullDown</apiname></xref> and

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Verify that the pin has been set to default to its low     

          electric state. Set <xref href="GUID-F9031EA4-2C8A-32CB-BB2B-26A20569866F.dita"><apiname>aBias</apiname></xref> to                <xref href="GUID-94DC7B4C-A782-3881-AC16-D982F206057A.dita"><apiname>EPullDown</apiname></xref>.

             </p> </li>

<li><p>                Implement <xref href="GUID-727E0B20-32AF-3CBE-B0AC-6381C16955F1.dita"><apiname>GetPinBias()</apiname></xref> with    

           <codeph>aBias</codeph> containing <xref href="GUID-EFC660F1-A375-304B-9866-C937D2A36AD9.dita"><apiname>EPullUp</apiname></xref> and

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Verify that the pin has been set to default to its high    

           electric state. Set <xref href="GUID-F9031EA4-2C8A-32CB-BB2B-26A20569866F.dita"><apiname>aBias</apiname></xref> to <xref href="GUID-EFC660F1-A375-304B-9866-C937D2A36AD9.dita"><apiname>EPullUp</apiname></xref>.

                            </p> </li>

<li><p>                Implement <xref href="GUID-727E0B20-32AF-3CBE-B0AC-6381C16955F1.dita"><apiname>GetPinBias()</apiname></xref> with return

value                <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.              </p> <p> 

              Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does 

              not support reading the pin bias.              </p> </li>

</ul> </li>

</ul> </section>

<section id="GUID-7ECD4CDD-1320-4AEA-AC9D-B2A473536C21"><title>Pin idle functions</title> <p>     Implement the pin idle

functions.   </p>  <ul>

<li><p>          Implement <xref href="GUID-0C5314C5-EE55-3974-8ED5-5AE26C0638F0.dita"><apiname>SetPinIdleConfigurationAndState()</apiname></xref> 

         with return value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p> 

        Return <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>         </p> </li>

<li><p>             Implement             <xref href="GUID-0C5314C5-EE55-3974-8ED5-5AE26C0638F0.dita"><apiname>SetPinIdleConfigurationAndState()</apiname></xref> with

return value             <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.           </p> <p> 

           Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does    

        not support the idle state.           </p> </li>

<li><p>             Implement             <xref href="GUID-4BF99D43-8F53-36B0-803D-FE86A1EF943A.dita"><apiname>GetPinIdleConfigurationAndState()</apiname></xref> with

return value             <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.           </p> <p> 

           Return <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>           </p> </li>

<li><p>                Implement                <xref href="GUID-4BF99D43-8F53-36B0-803D-FE86A1EF943A.dita"><apiname>GetPinIdleConfigurationAndState()</apiname></xref> with

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does 

              not support the idle state.              </p> </li>

</ul> </section>

<section id="GUID-1ECB1516-C554-4168-AE8C-FA4BDC7BF48F"><title>Interrupt functions</title> <p>     Implement the interrupt

functions.   </p> <ul>

<li><p>          Implement <xref href="GUID-6C16DEC3-D0F5-37C0-9EBD-19FE64472F38.dita"><apiname>BindInterrupt()</apiname></xref> with return

value          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Associate

the specified interrupt service routine with the          specified pin ID.

        </p> </li>

<li><p>          Implement <xref href="GUID-6C16DEC3-D0F5-37C0-9EBD-19FE64472F38.dita"><apiname>BindInterrupt()</apiname></xref> with return

value          <xref href="GUID-0BB03881-8862-35FC-8102-48A2932AB738.dita"><apiname>KErrInUse</apiname></xref>.         </p> <p>          Return <xref href="GUID-0BB03881-8862-35FC-8102-48A2932AB738.dita"><apiname>KErrInUse</apiname></xref> if

an interrupt service          routine is already bound to this interrupt.

        </p> </li>

<li><p>          Implement <xref href="GUID-590E49F1-73A2-3770-80D9-14710982B661.dita"><apiname>UnbindInterrupt()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Unbind

the specified interrupt service routine with the specified          pin ID.

        </p> </li>

<li><p>          Implement <xref href="GUID-34F2BB96-F39A-34D0-AEF4-543C11BD00FB.dita"><apiname>EnableInterrupt()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as an interrupt source and that          there

is an ISR bound to it. Enable the interrupt.         </p> </li>

<li><p>          Implement <xref href="GUID-E00AE446-FF29-3B97-A38D-5A6B05F51D81.dita"><apiname>DisableInterrupt()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as an interrupt source and that          there

is an ISR bound to it. Disable the interrupt.         </p> </li>

<li><p>          Implement <xref href="GUID-F8C65BDF-21E9-31C1-B124-8791C0A2E766.dita"><apiname>IsInterruptEnabled()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as an interrupt source and that          there

is an ISR bound to it. Determine the status of the interrupt. If it is   

      enabled set <codeph>aEnable</codeph> to True and if it is disabled set

         <xref href="GUID-28B9AB57-B1B6-3D84-A118-FAEA5AD2C23F.dita"><apiname>aEnable</apiname></xref> to False.         </p> </li>

<li><p>          Implement <xref href="GUID-1F8A4B69-BF3D-31C6-934D-93BF47E3E407.dita"><apiname>ClearInterrupt()</apiname></xref> with return

value          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Clear

the interrupt.         </p> <p>          Only implement this if the hardware

does not automatically clear          the interrupt after reading the interrupt

status.         </p> </li>

<li><p>          Implement <xref href="GUID-3B91EDB8-1BD0-3C13-BF9F-E0A11EC39F84.dita"><apiname>GetMaskedInterruptState()</apiname></xref> with

         return value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>      

   Read the interrupt state from the GPIO interrupt controller,          probably

by using a bit mask on a register. Set aActive to True if the          interrupt

state is active and to False if it is inactive.         </p> </li>

<li><p>          Implement <xref href="GUID-F5D98B1C-5397-3E2E-AEBC-E492FA0CBF91.dita"><apiname>GetRawInterruptState()</apiname></xref> with

return          value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>      

   Read the interrupt state directly from the pin. Set          <codeph>aActive</codeph> to

True if the interrupt state is active and to False if          it is inactive.

        </p> <p>          If the hardware does not allow the raw interrupt

state to be          read, implement the function to return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> or

         to return the same value as <xref href="GUID-3B91EDB8-1BD0-3C13-BF9F-E0A11EC39F84.dita"><apiname>GetMaskedInterruptState()</apiname></xref>.

        </p> </li>

<li><p>          Implement these functions with return value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>:

        </p> <ul>

<li><p>                <xref href="GUID-6C16DEC3-D0F5-37C0-9EBD-19FE64472F38.dita"><apiname>BindInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-590E49F1-73A2-3770-80D9-14710982B661.dita"><apiname>UnbindInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-34F2BB96-F39A-34D0-AEF4-543C11BD00FB.dita"><apiname>EnableInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-E00AE446-FF29-3B97-A38D-5A6B05F51D81.dita"><apiname>DisableInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-F8C65BDF-21E9-31C1-B124-8791C0A2E766.dita"><apiname>IsInterruptEnabled()</apiname></xref>           

  </p> </li>

</ul> <p>          Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> for these functions

         if the pin does not support interrupts.         </p> </li>

<li><p>          Implement these functions with return value          <xref href="GUID-A94AC24A-EADF-3913-8345-708ED637968E.dita"><apiname>KErrGeneral</apiname></xref>:

        </p> <ul>

<li><p>                <xref href="GUID-590E49F1-73A2-3770-80D9-14710982B661.dita"><apiname>UnbindInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-34F2BB96-F39A-34D0-AEF4-543C11BD00FB.dita"><apiname>EnableInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-E00AE446-FF29-3B97-A38D-5A6B05F51D81.dita"><apiname>DisableInterrupt()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-F8C65BDF-21E9-31C1-B124-8791C0A2E766.dita"><apiname>IsInterruptEnabled()</apiname></xref>           

  </p> </li>

</ul> <p>          Return <xref href="GUID-A94AC24A-EADF-3913-8345-708ED637968E.dita"><apiname>KErrGeneral</apiname></xref> for these functions

if          there is no Interrupt Service Routine bound to the pin.      

  </p> </li>

<li><p>          Implement <xref href="GUID-1F8A4B69-BF3D-31C6-934D-93BF47E3E407.dita"><apiname>ClearInterrupt()</apiname></xref> with return

value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         </p> <p>     

    Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does not       

  support clearing the interrupt signal.         </p> </li>

<li><p>          Implement <xref href="GUID-3B91EDB8-1BD0-3C13-BF9F-E0A11EC39F84.dita"><apiname>GetMaskedInterruptState()</apiname></xref> with

         return value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         </p> <p> 

        Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if reading the        

 interrupt state is not supported.         </p> </li>

<li><p>          Implement <xref href="GUID-F5D98B1C-5397-3E2E-AEBC-E492FA0CBF91.dita"><apiname>GetRawInterruptState()</apiname></xref> with

return          value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         </p> <p> 

        Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if reading raw        

 interrupt states is not supported.         </p> </li>

</ul> </section>

<section id="GUID-19811A8B-5A8F-4769-8686-1BB49C56532F"><title>Wakeup functions</title> <p>     Implement the wakeup functions.

  </p> <ul>

<li><p>                Implement <xref href="GUID-1C41DDCD-7BE3-3BDA-A832-C2C9821AEB09.dita"><apiname>EnableWakeup()</apiname></xref> with return

               value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p>  

             Enable wakeup on the pin.              </p> </li>

<li><p>                Implement <xref href="GUID-21432D3C-90DA-35AA-AFB5-C7FF37ED0806.dita"><apiname>DisableWakeup()</apiname></xref> with return

               value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p>  

             Disable wakeup on the pin.              </p> </li>

<li><p>                Implement <xref href="GUID-D58B6C13-F3B0-3E18-A7ED-DE177BC2CCEB.dita"><apiname>IsWakeupEnabled()</apiname></xref> with

return                value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Verify that the pin supports wakeup and determine the wakeup

               state. If is enabled set <xref href="GUID-28B9AB57-B1B6-3D84-A118-FAEA5AD2C23F.dita"><apiname>aEnable</apiname></xref> to True

and if it is                disabled set <xref href="GUID-28B9AB57-B1B6-3D84-A118-FAEA5AD2C23F.dita"><apiname>aEnable</apiname></xref> to False.

             </p> </li>

<li><p>          Implement these functions with return value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>:

        </p> <ul>

<li><p>                <xref href="GUID-1C41DDCD-7BE3-3BDA-A832-C2C9821AEB09.dita"><apiname>EnableWakeup()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-21432D3C-90DA-35AA-AFB5-C7FF37ED0806.dita"><apiname>DisableWakeup()</apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-D58B6C13-F3B0-3E18-A7ED-DE177BC2CCEB.dita"><apiname>IsWakeupEnabled()</apiname></xref>              </p> </li>

</ul> <p>          Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does

not          support wakeups.         </p> </li>

</ul>  </section>

<section id="GUID-505B2E66-80A7-423D-8BE9-D5325D02F006"><title>Trigger functions</title> <p>     Implement the trigger functions.

  </p> <ul>

<li><p>          Implement <xref href="GUID-29000C80-F7B6-3B7C-8944-F6BCAE2B6618.dita"><apiname>SetInterruptTrigger()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as an interrupt source and that          there

is an ISR bound to it. Set the interrupt trigger on the specified pin.   

     </p> </li>

<li><p>          Implement <xref href="GUID-29000C80-F7B6-3B7C-8944-F6BCAE2B6618.dita"><apiname>SetInterruptTrigger()</apiname></xref> with return

         value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         </p> <p>     

    Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does not       

  support interrupts.         </p> </li>

<li><p>          Implement <xref href="GUID-28F2D8DB-5D57-3199-9066-1B0252EE632E.dita"><apiname>SetWakeupTrigger()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as an interrupt source and that          there

is an ISR bound to it. Set the interrupt trigger on the specified pin.   

      The trigger should probably be edge detected.         </p> </li>

<li><p>          Implement <xref href="GUID-28F2D8DB-5D57-3199-9066-1B0252EE632E.dita"><apiname>SetWakeupTrigger()</apiname></xref> with return

         value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         </p> <p>     

    Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does not       

  support wakeups.         </p> </li>

</ul>  </section>

<section id="GUID-718F1593-206E-4738-A34A-C9D3F52063EE"><title>Debounce functions</title> <p>     Implement the debounce

functions.   </p> <ul>

<li><p>          Implement <xref href="GUID-837F3EC5-5379-3B88-B27B-A092E9F2E422.dita"><apiname>SetDebounceTime()</apiname></xref> with return

value          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the platform supports debouncing either by hardware          or software.

Use the passed in value as the sampling interval in milliseconds.         </p> <p> 

        Only implement this if the platform supports debouncing.         </p> </li>

<li><p>          Implement <xref href="GUID-72F9F470-4815-3674-A90F-1038C565F2E0.dita"><apiname>GetDebounceTime()</apiname></xref> with return

         value <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Determine

value in milliseconds of the sampling interval used in          debouncing

and set aTime to that value.         </p> <p>          Only implement this

if the platform supports debouncing.         </p> </li>

<li><p>          Implement these functions with return value          <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.

        </p> <ul>

<li><p>                <xref href="GUID-837F3EC5-5379-3B88-B27B-A092E9F2E422.dita"><apiname>SetDebounceTime() </apiname></xref>              </p> </li>

<li><p>                <xref href="GUID-72F9F470-4815-3674-A90F-1038C565F2E0.dita"><apiname>GetDebounceTime()</apiname></xref>              </p> </li>

</ul> <p>          Return <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref> if the pin does

not          support debouncing.         </p> </li>

</ul> </section>

<section id="GUID-84ACB7AB-F6DE-42F5-8C89-C7598FBC7AC1"><title>Input/output</title> <p>     Implement the input and output

state functions.   </p> <ul>

<li><p>          Implement <xref href="GUID-EB28CB99-7191-345B-90FC-7708E9D190C7.dita"><apiname>SetOutputState()</apiname></xref> for each value

of          <xref href="GUID-7C1D78B4-9897-3C38-8EE7-7C311B885B0B.dita"><apiname>TGpioState</apiname></xref>.         </p> <ul>

<li><p>                Implement <xref href="GUID-EB28CB99-7191-345B-90FC-7708E9D190C7.dita"><apiname>SetOutputState()</apiname></xref> with

               <codeph>aState</codeph> == <xref href="GUID-ABF52F3A-CDC3-3AC6-89ED-FB7F5B781A25.dita"><apiname>ELow</apiname></xref> and return

value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p>  

             Verify that the pin is being used as a binary output. Set it

               to its low electric state.              </p> </li>

<li><p>                Implement <xref href="GUID-EB28CB99-7191-345B-90FC-7708E9D190C7.dita"><apiname>SetOutputState()</apiname></xref> with

               <codeph>aState</codeph> == <xref href="GUID-28B7F356-760B-38EA-90B1-AD3594375CBC.dita"><apiname>EHigh</apiname></xref> and return

value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p>  

             Verify that the pin is being used as a binary output. Set it

               to its high electric state.              </p> </li>

<li><p>                Implement <xref href="GUID-EB28CB99-7191-345B-90FC-7708E9D190C7.dita"><apiname>SetOutputState()</apiname></xref> with

               <codeph>aState</codeph> == <xref href="GUID-A538A8AF-DA50-3641-A794-19CAFF5B28F2.dita"><apiname>EDefaultIdleState</apiname></xref> and

return value                <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.              </p> <p> 

              Verify that the pin is being used as a binary output. Set its

               electric state to its default idle state.              </p> </li>

<li><p>                Implement <xref href="GUID-EB28CB99-7191-345B-90FC-7708E9D190C7.dita"><apiname>SetOutputState()</apiname></xref> with

return                value <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.         

    </p> <p>                If the specified electric state is not supported

return                <xref href="GUID-F89DA3F0-2A48-3F9B-8F08-29350E92D0E4.dita"><apiname>KErrNotSupported</apiname></xref>.              </p> </li>

</ul> </li>

<li><p>          Implement <xref href="GUID-E88C05CA-8882-3C6A-9B64-8048DB7DA622.dita"><apiname>GetOutputState()</apiname></xref> with return

value          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as a binary output. Determine          its electric

state and set <codeph>aState</codeph> to the appropriate value of        

 <xref href="GUID-7C1D78B4-9897-3C38-8EE7-7C311B885B0B.dita"><apiname>TGpioState</apiname></xref>.         </p> </li>

<li><p>          Implement <xref href="GUID-9BFB4B87-1400-33C0-B116-AC6FA349BE1E.dita"><apiname>GetInputState()</apiname></xref> with return

value          <xref href="GUID-6CA4F1ED-7947-3087-B618-D35858FAA3BC.dita"><apiname>KErrNone</apiname></xref>.         </p> <p>          Verify

that the pin is being used as a binary input. Determine          its electric

state and set <codeph>aState</codeph> to the appropriate value of        

 <xref href="GUID-7C1D78B4-9897-3C38-8EE7-7C311B885B0B.dita"><apiname>TGpioState</apiname></xref>.         </p> </li>

</ul></section>

<section id="GUID-DF48097B-9247-4817-9651-71C715FF5E09"><title>Static extension</title> <ul>

<li><p>          Implement <xref href="GUID-821EF2E4-8DC9-3058-8CFD-53F3268264ED.dita"><apiname>StaticExtension()</apiname></xref> if necessary.

        </p> </li>

</ul></section>

</conbody><related-links>

<link href="GUID-0E15C8C4-E511-569F-8AB4-895CA00331AB.dita"><linktext>GPIO Features</linktext>

</link>

<link href="GUID-745273E3-BB3A-59BF-9C33-6C8BB3D850A9.dita"><linktext>GPIO Design

Considerations</linktext></link>

</related-links></concept>