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<concept id="GUID-A5D862E4-3EC3-45C0-B635-23A02E5BB11F" xml:lang="en"><title>GPIO

Overview</title><shortdesc> General Purpose Input/Output (GPIO) allows easy serial expansion

of I/O through an interface.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>GPIO provides additional control and monitoring when the microcontroller

or chipset has insufficient I/O ports, or in systems where serial communication

and control from a remote location is advantageous. </p>

<section id="GUID-00227A5E-77BF-434F-B84F-880742E59151"><title>Required background</title><p>Before

beginning you should know the following:</p><ul>

<li><p>Understand platform implementation.</p></li>

<li><p>Understand GPIO concepts and terminology.</p></li>

<li><p>Know the architecture of the platform on which you are implementing.</p></li>

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

</ul></section>

<section id="GUID-A4ECE25C-66A4-4161-9BD7-9FA431D5EE71"><title>Architecture

Description</title><p>There are two parts of a GPIO. They are the input path

and the output path.</p><ul>

<li><p><b>Input Path:</b></p> The input path is used to connect an external

signal to the internals of the microprocessor. This mode is generally used

for analog input and output to avoid oscillations in the internal digital

data bus when the signal level at the input is near the HIGH or LOW threshold. </li>

</ul><ul>

<li><p><b>Output Path:</b></p> The output path is used to bring external signals

from the internals of the microprocessor to the external world.</li>

</ul></section>

</conbody></concept>