1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3 4<head> 5<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 6<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 8.0.2.0 for Windows"> 7<META http-equiv="Content-Style-Type" content="text/css"> 8<title>WM_StartDataSharing</title> 9<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 10</head> 11 12<body> 13 14<h1 align="left">WM_StartDataSharing <img src="../../image/NTR.gif"><img src="../../image/TWL.gif"></H1> 15<h2>Syntax</h2> 16<dl> 17 <dd><PRE><CODE>#include <nitro/wm.h> 18 19<A href="WMErrCode.html">WMErrCode</A> WM_StartDataSharing( 20 WMDataSharingInfo* dsInfo , 21 u16 port , 22 u16 aidBitmap , 23 u16 dataLength , 24 BOOL doubleMode 25); 26</CODE></PRE></dd> 27</dl> 28 29<h2>Arguments</h2> 30<table border="1" width="100%"> 31 <tbody> 32 <TR> 33<TD width="200"><CODE>dsInfo</CODE></TD> 34<TD width="800">Pointer to the data sharing information structure. The buffer must separately allocate each group that performs data sharing. Because the buffer is cache-controlled, it must be 32-byte aligned.</TD> 35 </TR> 36 <TR> 37<TD width="200"><CODE>port</CODE></TD> 38<TD width="800"><a href="WMPort.html">Port number</a> that performs data sharing. Use a value between 0 and 15.</TD> 39 </TR> 40 <TR> 41<TD width="200"><CODE>aidBitmap</CODE></TD> 42<TD width="800">Poll map of the AID of the terminal that performs data sharing. When data sharing with the maximum 16 units, it is <CODE>0xFFFF</CODE>.</TD> 43 </TR> 44 <TR> 45<TD width="200"><CODE>dataLength</CODE></TD> 46<TD width="800">Data length for one child to share. This must be a byte length that is a multiple of 2.</TD> 47 </TR> 48 <TR> 49<TD width="200"><CODE>doubleMode</CODE></TD> 50<TD width="800"><CODE>TRUE</CODE> for using data sharing in every frame in the mode that executes one MP communication per frame.</TD> 51 </TR> 52 </tbody> 53</table> 54 55<h2>Return Values</h2> 56<p>Returns the results of the <A href="WMErrCode.html"><CODE>WMErrCode</CODE></A> enumerated type process.</p> 57 58<H2>Description</H2> 59<P> 60Initializes data sharing. This function can be run when the WM is in either the <a href="wm_state_diagram.html"><code>MP_PARENT</code></a> state or the <a href="wm_state_diagram.html"><code>MP_CHILD</code></a> state. This is a synchronous function that promptly returns the <code>WM_ERRCODE_SUCCESS</code> return value when the process succeeds.<br />Be sure to call <CODE>WM_StartDataSharing</CODE> immediately after <a href="WM_StartMP.html"><code>WM_StartMP</code></a>. Processing and communication does not occur regularly simply by calling this function. Processing is started by calling the <A href="WM_StepDataSharing.html"><CODE>WM_StepDataSharing</CODE></A> function. For parents, it is possible to perform parallel data sharing for multiple groups. Prepare the <code>WMDataSharingInfo</code> structure for each group and call this function multiple times for different port numbers. You cannot specify a value (number of group terminals performing data sharing × shared data size) that exceeds the permitted range from the length limit (508 bytes) of data that the parent can send at once. When a value of <CODE>TRUE</CODE> is specified in the <CODE>doubleMode</CODE> argument, the value that can be obtained with the <a href="WM_StepDataSharing.html"><code>WM_StepDataSharing</code></a> function will be the value that was set by the <a href="WM_StepDataSharing.html"><code>WM_StepDataSharing</code></a> function two calls earlier. <A href="WM_StepDataSharing.html">WM_StepDataSharing</A> can be called for each round of MP communication. When a value of <CODE>FALSE</CODE> is specified, it is possible to get the value that was specified immediately beforehand, but it requires at least two intervals of MP communications for <a href="WM_StepDataSharing.html"><code>WM_StepDataSharing</code></a> to succeed. 61</P> 62 63<P>For the <CODE>mpFreq</CODE> argument of <A href="WM_StartMP.html"><code>WM_StartMP</code></A> and the parameters of <A href="WM_StepDataSharing.html"><CODE>WM_StepDataSharing</CODE></A>, the data sharing success interval and communication delay of shared data correspond as shown below. 64</P> 65<table border="1"> 66 <tbody> 67 <tr> 68<td><B>mpFreq</B></td> 69<td><B>doubleMode</B></td> 70<td><B>Data Sharing Intervals</B></td> 71<td><B>Delay</B></td> 72<td><B>Comments</B></td> 73 </tr> 74 <tr> 75 <td>1</td> 76<td><CODE>TRUE</CODE></td> 77<td>Every frame</td> 78<td>2 frames</td> 79<td>If <CODE>doubleMode</CODE> is set to <CODE>TRUE</CODE>, it adds one set of buffering, and the delay increases.</td> 80 </tr> 81 <tr> 82<td>2 or more, or 0 (continuous communication mode)</td> 83<td><CODE>FALSE</CODE></td> 84<td>Every frame</td> 85<td>1 frame</td> 86<td>During execution more than 2 rounds of MP communication per frame, data can be shared in every frame even when <CODE>doubleMode</CODE> is set to <CODE>FALSE</CODE>. However, it is more likely to cause errors and increase power consumption, so use it with caution. </td> 87 </tr> 88 <tr> 89 <td>1</td> 90<td><CODE>FALSE</CODE></td> 91<td>2 or more frames </td> 92<td>2 or more frames</td> 93<td>When data sharing is executed at intervals of 2 or more frames, <CODE>doubleMode</CODE> can be <CODE>FALSE</CODE> even if <CODE>mpFreq</CODE> is 1. Therefore, the delay time equals the data sharing interval.</td> 94 </tr> 95 </tbody> 96</table> 97 98 99<h2>See Also</h2> 100<P><a href="WM_EndDataSharing.html"><code>WM_EndDataSharing</code></a><BR> <a href="WM_StepDataSharing.html"><code>WM_StepDataSharing</code></a><BR> <a href="WMPort.html"><code>WMPort</code></a></P> 101 102<H2>Revision History</H2> 103<P> 1042005/03/02 Added description of allowable range for port argument.<BR> 2004/10/25 Changed maximum value of shared data to 508 bytes.<BR> 2004/10/22 Changed return value type.<BR> 2004/09/25 Added and revised <B>Description</B>.<BR> 2004/08/31 Added <CODE>doubleMode</CODE> to <B>Arguments</B>.<BR> 2004/08/11 Initial version. 105</P> 106<hr><p>CONFIDENTIAL</p></body> 107</html> 108
