1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> 2<head> 3<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 4<title>SND_SetupChannelPsg</title> 5<link rel="stylesheet" href="../css/nitro.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.65.1"> 7</head> 8<body> 9<div class="refentry" lang="ja"><a name="IDAFLWT"></a><div class="titlepage"> 10<div></div> 11<div></div> 12</div> 13<h1>SND_SetupChannelPsg <IMG src="../image/NTR.gif" width="24" height="12" border="0" align=middle><IMG src="../image/TWL.gif" width="24" height="12" border="0" align=middle></h1> 14<h2>Syntax</h2> 15<dl> 16<dd><pre class="funcsynopsisinfo"><code>#include <nitro/snd.h></code></pre></dd> 17<dd><pre class="funcprototype"><code class="funcprototype">void SND_SetupChannelPsg( 18 int <var>chNo</var>, 19 SNDDuty <var>duty</var>, 20 int <var>volume</var>, 21 SNDChannelDataShift <var>shift</var>, 22 int <var>timer</var>, 23 int <var>pan</var> );</code><br></pre></dd> 24</dl> 25<div class="refsection" lang="ja"><a name="IDAONWT"></a> 26 <h2>Arguments</h2> 27 28 <div class="variablelist"> 29<table border="0"> 30<col align="left" valign="top"> 31<tbody> 32<tr> 33<td><em><strong><code>chNo</code></strong></em></td> 34<td>The channel number. Takes a value between 8 and 13.</td> 35</tr> 36<tr> 37<td><em><strong><code>duty</code></strong></em></td> 38<td>Duty ratio.</td> 39</tr> 40<tr> 41<td><em><strong><code>volume</code></strong></em></td> 42<td>The volume. Takes a value between 0 and 127.</td> 43</tr> 44<tr> 45<td><em><strong><code>shift</code></strong></em></td> 46<td>Data shift specification.</td> 47</tr> 48<tr> 49<td><em><strong><code>timer</code></strong></em></td> 50<td>The timer. Takes a value between 0x10 and 0xffff.</td> 51</tr> 52<tr> 53<td><em><strong><code>pan</code></strong></em></td> 54<td>The pan. Takes values in the range of 0 (left) to 64 (center) to 127 (right).</td> 55</tr> 56</tbody> 57</table> 58</div> 59 60 </div> 61<div class="refsection" lang="ja"><a name="IDAAPWT"></a> 62 <h2>Return Values</h2> 63 64 <p>None.</p> 65 </div> 66<div class="refsection" lang="ja"><a name="IDAHPWT"></a> 67 <h2>Description</h2> 68 <p> 69This function sets up a channel for playing PSG rectangular waves. 70</p> 71 <p> 72The function sets the parameters for the channel specified by <em><strong><code>chNo</code></strong></em>. The channel must first be locked by the <tt class="function"><a href="SND_LockChannel.html">SND_LockChannel</a></tt> function. Once the parameters have been set, call the <tt class="function"><a href="SND_StartTimer.html">SND_StartTimer</a></tt> function to begin actual playback. 73</p> 74 <p> 75Select the PSG rectangular wave duty ratio <em><strong><code>duty</code></strong></em> from the following values: 76</p> 77 <div class="table"><a name="IDAEQWT"></a><p class="title"><b>Table: SNDDuty</b></p> 78<table summary="SNDDuty" border="1"> 79<colgroup><col><col></colgroup> 80<thead> 81<tr> 82<th>Label</th> 83<th>Description</th> 84</tr> 85</thead> 86<tbody> 87<tr> 88<td>SND_DUTY_1_8</td> 89<td>1/8 (12.5%) duty</td> 90</tr> 91<tr> 92<td>SND_DUTY_2_8</td> 93<td>2/8 (25.0%) duty</td> 94</tr> 95<tr> 96<td>SND_DUTY_3_8</td> 97<td>3/8 (37.5%) duty</td> 98</tr> 99<tr> 100<td>SND_DUTY_4_8</td> 101<td>4/8 (50.0%) duty</td> 102</tr> 103<tr> 104<td>SND_DUTY_5_8</td> 105<td>5/8 (62.5%) duty</td> 106</tr> 107<tr> 108<td>SND_DUTY_6_8</td> 109<td>6/8 (75.0%) duty</td> 110</tr> 111<tr> 112<td>SND_DUTY_7_8</td> 113<td>7/8 (87.5%) duty</td> 114</tr> 115</tbody> 116</table> 117</div> 118 119 <p> 120Choose from among these values for the data shift setting <code>shift</code>: 121</p> 122 <div class="table"><a name="IDAQSWT"></a><p class="title"><b><b>Table. SNDChannelDataShift</b></b></p> 123<table summary="SNDChannelDataShift" border="1"> 124<colgroup><col><col></colgroup> 125<thead> 126<tr> 127<th>Label</th> 128<th>Description</th> 129</tr> 130</thead> 131<tbody> 132<tr> 133<td>SND_CHANNEL_DATASHIFT_NONE</td> 134<td>Do not perform a data shift.</td> 135</tr> 136<tr> 137<td>SND_CHANNEL_DATASHIFT_1BIT</td> 138<td>Shift data 1 bit right.</td> 139</tr> 140<tr> 141<td>SND_CHANNEL_DATASHIFT_2BIT</td> 142<td>Shift data 2 bits right.</td> 143</tr> 144<tr> 145<td>SND_CHANNEL_DATASHIFT_4BIT</td> 146<td>Shift data 4 bits right.</td> 147</tr> 148</tbody> 149</table> 150</div> 151 152 <p> 153<em>timer</em> specifies 8 cycles of white noise by clock count. The number of ticks per second is approximately 16.757 MHz with <code>SND_TIMER_CLOCK</code>. For example, the following calculation will play a pitch that has a frequency <em>freq</em> Hz. 154</p> 155<pre class="programlisting">timer = <code>SND_TIMER_CLOCK</code> / ( 8 * <em>freq</em> )</pre> 156 <p> 157 158</p> 159 <div class="note"> 160<h3 class="title">Note</h3> 161<p> 162This function is an ARM7 reserved function. After this function is called, its processing will occur only after the command is issued with the <tt class="function"><a href="SND_FlushCommand.html">SND_FlushCommand</a></tt> function. 163</p> 164<p> 165If program execution must be synchronized with process completion, first use the <tt class="function"><a href="SND_GetCurrentCommandTag.html">SND_GetCurrentCommandTag</a></tt> function to obtain the command tag immediately after calling this function. Then, after the command is issued, use the command tag and call either the <tt class="function"><a href="SND_IsFinishedCommandTag.html">SND_IsFinishedCommandTag</a></tt> or <tt class="function"><a href="SND_WaitForCommandProc.html">SND_WaitForCommandProc</a></tt> function to confirm that processing has finished or to wait for it to complete. 166</p> 167</div> 168 </div> 169<h2>See Also</h2> 170<p><code><a href="SND_LockChannel.html">SND_LockChannel</a>, <a href="SND_StartTimer.html">SND_StartTimer</a>, <a href="SND_FlushCommand.html">SND_FlushCommand</a>, <a href="SND_GetCurrentCommandTag.html">SND_GetCurrentCommandTag</a>, <a href="SND_IsFinishedCommandTag.html">SND_IsFinishedCommandTag</a>, <a href="SND_WaitForCommandProc.html">SND_WaitForCommandProc</a></code></p> 171<h2>Revision History</h2> 172<p>2005/02/17 Added a note about ARM7 command processing.<br /> 2004/08/10 Initial version.</p> 173</div> 174<hr><p>CONFIDENTIAL</p></body> 175</html> 176
