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

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     7     Nokia Corporation - initial contribution.

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    10 <!DOCTYPE concept

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

    12 <concept id="GUID-8FA1B2B0-5842-4D5D-BD61-C2D79B56ADC6" xml:lang="en"><title>Interrupt Service Routine (ISR)</title><shortdesc>This document describes interrupt service routines as used by device

    13 drivers.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>An ISR is a static function that will be executed when an interrupt occurs

    15 on the interrupt source bound to the ISR. </p>

    16 <codeblock id="GUID-E8416619-9314-5420-8EC1-F8BF804230DF" xml:space="preserve">// Interrupt service routines

    17 static void UartIsr(TAny* aParam);

    18 </codeblock>

    19 <p>An ISR performs the actions necessary to service the event of the peripheral

    20 that generated the interrupt and to remove the condition that caused it to

    21 interrupt. It queues a DFC to do the required processing. It disables the

    22 interrupts and FIQs on ARM, if required, to handle the interrupt, and enables

    23 them before leaving. It can also disable the source of the interrupt that

    24 it is servicing. </p>

    25 </conbody></concept>