1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 7.0.0.0 for Windows"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<TITLE>OS_SetPeriodicVAlarm</TITLE> 8<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 9</HEAD> 10<BODY> 11<H1 align="left">OS_SetPeriodicVAlarm <IMG src="../../image/NTR.gif" align="middle"><IMG src="../../image/TWL.gif" align="middle"></H1> 12<H2>Syntax</H2> 13<DL> 14 <DD> 15 <PRE><CODE>#include <nitro/os.h></CODE></PRE> 16 <PRE><CODE>void OS_SetPeriodicVAlarm( 17 OSVAlarm* alarm , 18 s16 count , 19 s16 delay , 20 OSVAlarmHandler handler , 21 void* arg ); </CODE></PRE> 22</DL> 23<H2>Arguments</H2> 24<TABLE border="1" width="100%"> 25 <TBODY> 26 <TR> 27 <TD width="13%"><EM><STRONG>alarm</STRONG></EM></TD> 28 <TD width="87%">Pointer to the V-Count alarm structure for setting V-Count alarm</TD> 29 </TR> 30 <TR> 31 <TD width="13%"><EM><STRONG>count</STRONG></EM></TD> 32 <TD width="87%">The V-Count at which the V-Count alarm will be actuated (handler will be called) in each frame.</TD> 33 </TR> 34 <TR> 35 <TD><EM><STRONG>delay</STRONG></EM></TD> 36 <TD>The maximum permissible number of V-Counts for delay.</TD> 37 </TR> 38 <TR> 39 <TD><EM><STRONG>handler</STRONG></EM></TD> 40 <TD>The V-Count alarm handler</TD> 41 </TR> 42 <TR> 43 <TD><EM><STRONG>arg</STRONG></EM></TD> 44 <TD>The argument used when the V-Count alarm handler is called</TD> 45 </TR> 46 </TBODY> 47</TABLE> 48<H2>Return Values</H2> 49<P>None.</P> 50<H2>Description</H2> 51<P>Sets a periodic V-Count alarm.</P> 52<P>In each frame, <code><strong><em>handler</em></strong></code> is called when the V-Count reaches <code><strong><em>count</em></strong></code>. The V-Count alarm handler <code>handler</code> is an <code>OSVAlarmHandler</code> function defined by the following:</P> 53<P> <CODE>typedef void (*OSVAlarmHandler)( void* );</CODE></P> 54<P> <B><I>handler</I></B> is called from the OS V-Count interrupt handler. Therefore, interrupts are prohibited. When the <em><strong><code>handler</code></strong></em> is called, it takes <code><strong><em>arg</em></strong></code> as an argument.</P> 55<P>It is possible to specify the amount of permissible delay when the hander cannot be called at the exact number of specified V-Count because of another V-Count alarm or interrupt. For example, at count=100 and delay=5, V-Count is called if it is possible to call it by count 105, even if it was not possible to call it by count 100. When you specify <code>0</code>, the alarm is called only at the specified V-Count. If <code>OS_VALARM_DELAY_MAX</code>, it is always called when a call is possible for the specified V-Count and subsequent V-Counts. For details, see the description in <a href="about_VAlarm.html">VAlarm Overview</a>.</P> 56<P>If <em><strong><code>alarm</code></strong></em> is specified for the pointer to the <code>OSAlarm</code> structure in which the V-Count has been set, it stops with <a href="../debug/OS_Panic.html"><code>OS_Panic()</code></a>.</P> 57<P><code><a href="OS_CancelVAlarm.html">OS_CancelVAlarm()</a></code> or <code><a href="OS_CancelVAlarms.html">OS_CancelVAlarms()</a></code> is used to stop the V-Count alarm.</P> 58<H2>See Also</H2> 59<P><CODE><A href="OS_InitVAlarm.html">OS_InitVAlarm</A>, 60 <A href="OS_CreateVAlarm.html">OS_CreateVAlarm</A>, 61 <A href="OS_SetVAlarm.html">OS_SetVAlarm</A>,<BR> <A href="OS_CancelVAlarm.html">OS_CancelVAlarm</A>, <A href="OS_CancelVAlarms.html">OS_CancelVAlarms</A><BR></CODE></P> 62<H2>Revision History</H2> 63<P> 642005/03/08 Standardized the use of the term 'interrupt' in Japanese.<br>2004/08/30 Added statement about not being able to use the set V alarm structure.<br>2004/07/06 Added statement about delay.<br>2004/02/24 Initial version</P> 65<hr><p>CONFIDENTIAL</p></body> 66</HTML>
