1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<title>Matrix Multiplication</title>
<title>CMSIS-DSP: Matrix Multiplication</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<link href="cmsis.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<script type="text/javascript" src="printComponentTabs.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
$(document).ready(initResizable);
</script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
<link href="stylsheetf" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 46px;">
<td id="projectlogo"><img alt="Logo" src="CMSIS_Logo_Final.png"/></td>
<td style="padding-left: 0.5em;">
<div id="projectname">CMSIS-DSP
 <span id="projectnumber">Version 1.4.7</span>
</div>
<div id="projectbrief">CMSIS DSP Software Library</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<div id="CMSISnav" class="tabs1">
<ul class="tablist">
<script type="text/javascript">
<!--
writeComponentTabs.call(this);
//-->
</script>
</ul>
</div>
<!-- Generated by Doxygen 1.8.2 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main Page</span></a></li>
<li><a href="pages.html"><span>Usage and Description</span></a></li>
<li><a href="modules.html"><span>Reference</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
$(document).ready(function(){initNavTree('group___matrix_mult.html','');});
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Data Structures</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark"> </span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark"> </span>Enumerator</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark"> </span>Macros</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(9)"><span class="SelectionMark"> </span>Groups</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(10)"><span class="SelectionMark"> </span>Pages</a></div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<div class="header">
<div class="summary">
<a href="#func-members">Functions</a> </div>
<div class="headertitle">
<div class="title">Matrix Multiplication</div> </div>
<div class="ingroups"><a class="el" href="group__group_matrix.html">Matrix Functions</a></div></div><!--header-->
<div class="contents">
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:ga917bf0270310c1d3f0eda1fc7c0026a0"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group___matrix_mult.html#ga917bf0270310c1d3f0eda1fc7c0026a0">arm_mat_mult_f32</a> (const <a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> *pSrcA, const <a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> *pSrcB, <a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> *pDst)</td></tr>
<tr class="memdesc:ga917bf0270310c1d3f0eda1fc7c0026a0"><td class="mdescLeft"> </td><td class="mdescRight">Floating-point matrix multiplication. <a href="#ga917bf0270310c1d3f0eda1fc7c0026a0"></a><br/></td></tr>
<tr class="separator:ga917bf0270310c1d3f0eda1fc7c0026a0"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga08f37d93a5bfef0c5000dc5e0a411f93"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group___matrix_mult.html#ga08f37d93a5bfef0c5000dc5e0a411f93">arm_mat_mult_fast_q15</a> (const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pSrcA, const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pSrcB, <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pDst, <a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> *pState)</td></tr>
<tr class="memdesc:ga08f37d93a5bfef0c5000dc5e0a411f93"><td class="mdescLeft"> </td><td class="mdescRight">Q15 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4. <a href="#ga08f37d93a5bfef0c5000dc5e0a411f93"></a><br/></td></tr>
<tr class="separator:ga08f37d93a5bfef0c5000dc5e0a411f93"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga2785e8c1b785348b0c439b56aaf585a3"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group___matrix_mult.html#ga2785e8c1b785348b0c439b56aaf585a3">arm_mat_mult_fast_q31</a> (const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pSrcA, const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pSrcB, <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pDst)</td></tr>
<tr class="memdesc:ga2785e8c1b785348b0c439b56aaf585a3"><td class="mdescLeft"> </td><td class="mdescRight">Q31 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4. <a href="#ga2785e8c1b785348b0c439b56aaf585a3"></a><br/></td></tr>
<tr class="separator:ga2785e8c1b785348b0c439b56aaf585a3"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga3657b99a9667945373e520dbac0f4516"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group___matrix_mult.html#ga3657b99a9667945373e520dbac0f4516">arm_mat_mult_q15</a> (const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pSrcA, const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pSrcB, <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> *pDst, <a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> *pState CMSIS_UNUSED)</td></tr>
<tr class="memdesc:ga3657b99a9667945373e520dbac0f4516"><td class="mdescLeft"> </td><td class="mdescRight">Q15 matrix multiplication. <a href="#ga3657b99a9667945373e520dbac0f4516"></a><br/></td></tr>
<tr class="separator:ga3657b99a9667945373e520dbac0f4516"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga2ec612a8c2c4916477fb9bc1ab548a6e"><td class="memItemLeft" align="right" valign="top"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group___matrix_mult.html#ga2ec612a8c2c4916477fb9bc1ab548a6e">arm_mat_mult_q31</a> (const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pSrcA, const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pSrcB, <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> *pDst)</td></tr>
<tr class="memdesc:ga2ec612a8c2c4916477fb9bc1ab548a6e"><td class="mdescLeft"> </td><td class="mdescRight">Q31 matrix multiplication. <a href="#ga2ec612a8c2c4916477fb9bc1ab548a6e"></a><br/></td></tr>
<tr class="separator:ga2ec612a8c2c4916477fb9bc1ab548a6e"><td class="memSeparator" colspan="2"> </td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Description</h2>
<p>Multiplies two matrices.</p>
<div class="image">
<img src="MatrixMultiplication.gif" alt="MatrixMultiplication.gif"/>
<div class="caption">
Multiplication of two 3 x 3 matrices</div></div>
<p>Matrix multiplication is only defined if the number of columns of the first matrix equals the number of rows of the second matrix. Multiplying an <code>M x N</code> matrix with an <code>N x P</code> matrix results in an <code>M x P</code> matrix. When matrix size checking is enabled, the functions check: (1) that the inner dimensions of <code>pSrcA</code> and <code>pSrcB</code> are equal; and (2) that the size of the output matrix equals the outer dimensions of <code>pSrcA</code> and <code>pSrcB</code>. </p>
<h2 class="groupheader">Function Documentation</h2>
<a class="anchor" id="ga917bf0270310c1d3f0eda1fc7c0026a0"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> arm_mat_mult_f32 </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> * </td>
<td class="paramname"><em>pSrcA</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> * </td>
<td class="paramname"><em>pSrcB</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="structarm__matrix__instance__f32.html">arm_matrix_instance_f32</a> * </td>
<td class="paramname"><em>pDst</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcA</td><td>points to the first input matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcB</td><td>points to the second input matrix structure </td></tr>
<tr><td class="paramdir">[out]</td><td class="paramname">*pDst</td><td>points to output matrix structure </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The function returns either <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking. </dd></dl>
<dl><dt><b>Examples: </b></dt><dd><a class="el" href="arm_class_marks_example_f32_8c-example.html#a17">arm_class_marks_example_f32.c</a>, and <a class="el" href="arm_matrix_example_f32_8c-example.html#a13">arm_matrix_example_f32.c</a>.</dd>
</dl>
<p>References <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a7071b92f1f6bc3c5c312a237ea91105b">ARM_MATH_SIZE_MISMATCH</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>, <a class="el" href="structarm__matrix__instance__f32.html#acdd1fb73734df68b89565c54f1dd8ae2">arm_matrix_instance_f32::numCols</a>, <a class="el" href="structarm__matrix__instance__f32.html#a23f4e34d70a82c9cad7612add5640b7b">arm_matrix_instance_f32::numRows</a>, <a class="el" href="structarm__matrix__instance__f32.html#af3917c032600a9dfd5ed4a96f074910a">arm_matrix_instance_f32::pData</a>, and <a class="el" href="_a_r_m_2arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>.</p>
<p>Referenced by <a class="el" href="_a_r_m_2arm__class__marks__example__f32_8c.html#a196718f834091385d38586a0ce4009dc">main()</a>.</p>
</div>
</div>
<a class="anchor" id="ga08f37d93a5bfef0c5000dc5e0a411f93"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> arm_mat_mult_fast_q15 </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pSrcA</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pSrcB</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pDst</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> * </td>
<td class="paramname"><em>pState</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcA</td><td>points to the first input matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcB</td><td>points to the second input matrix structure </td></tr>
<tr><td class="paramdir">[out]</td><td class="paramname">*pDst</td><td>points to output matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pState</td><td>points to the array for storing intermediate results </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The function returns either <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.</dd></dl>
<p><b>Scaling and Overflow Behavior:</b></p>
<dl class="section user"><dt></dt><dd>The difference between the function <a class="el" href="group___matrix_mult.html#ga3657b99a9667945373e520dbac0f4516" title="Q15 matrix multiplication.">arm_mat_mult_q15()</a> and this fast variant is that the fast variant use a 32-bit rather than a 64-bit accumulator. The result of each 1.15 x 1.15 multiplication is truncated to 2.30 format. These intermediate results are accumulated in a 32-bit register in 2.30 format. Finally, the accumulator is saturated and converted to a 1.15 result.</dd></dl>
<dl class="section user"><dt></dt><dd>The fast version has the same overflow behavior as the standard version but provides less precision since it discards the low 16 bits of each multiplication result. In order to avoid overflows completely the input signals must be scaled down. Scale down one of the input matrices by log2(numColsA) bits to avoid overflows, as a total of numColsA additions are computed internally for each output element.</dd></dl>
<dl class="section user"><dt></dt><dd>See <code><a class="el" href="group___matrix_mult.html#ga3657b99a9667945373e520dbac0f4516" title="Q15 matrix multiplication.">arm_mat_mult_q15()</a></code> for a slower implementation of this function which uses 64-bit accumulation to provide higher precision. </dd></dl>
<p>References <a class="el" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248">__SIMD32</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a7071b92f1f6bc3c5c312a237ea91105b">ARM_MATH_SIZE_MISMATCH</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>, <a class="el" href="structarm__matrix__instance__q15.html#acbbce67ba058d8e1c867c71d57288c97">arm_matrix_instance_q15::numCols</a>, <a class="el" href="structarm__matrix__instance__q15.html#a9bac6ed54be287c4d4f01a1a28be65f5">arm_matrix_instance_q15::numRows</a>, <a class="el" href="structarm__matrix__instance__q15.html#a6da33a5553e634787d0f515cf8d724af">arm_matrix_instance_q15::pData</a>, and <a class="el" href="_a_r_m_2arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>.</p>
</div>
</div>
<a class="anchor" id="ga2785e8c1b785348b0c439b56aaf585a3"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> arm_mat_mult_fast_q31 </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pSrcA</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pSrcB</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pDst</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcA</td><td>points to the first input matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcB</td><td>points to the second input matrix structure </td></tr>
<tr><td class="paramdir">[out]</td><td class="paramname">*pDst</td><td>points to output matrix structure </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The function returns either <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.</dd></dl>
<p><b>Scaling and Overflow Behavior:</b></p>
<dl class="section user"><dt></dt><dd>The difference between the function <a class="el" href="group___matrix_mult.html#ga2ec612a8c2c4916477fb9bc1ab548a6e" title="Q31 matrix multiplication.">arm_mat_mult_q31()</a> and this fast variant is that the fast variant use a 32-bit rather than a 64-bit accumulator. The result of each 1.31 x 1.31 multiplication is truncated to 2.30 format. These intermediate results are accumulated in a 32-bit register in 2.30 format. Finally, the accumulator is saturated and converted to a 1.31 result.</dd></dl>
<dl class="section user"><dt></dt><dd>The fast version has the same overflow behavior as the standard version but provides less precision since it discards the low 32 bits of each multiplication result. In order to avoid overflows completely the input signals must be scaled down. Scale down one of the input matrices by log2(numColsA) bits to avoid overflows, as a total of numColsA additions are computed internally for each output element.</dd></dl>
<dl class="section user"><dt></dt><dd>See <code><a class="el" href="group___matrix_mult.html#ga2ec612a8c2c4916477fb9bc1ab548a6e" title="Q31 matrix multiplication.">arm_mat_mult_q31()</a></code> for a slower implementation of this function which uses 64-bit accumulation to provide higher precision. </dd></dl>
<p>References <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a7071b92f1f6bc3c5c312a237ea91105b">ARM_MATH_SIZE_MISMATCH</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>, <a class="el" href="structarm__matrix__instance__q31.html#abd161da7614eda927157f18b698074b1">arm_matrix_instance_q31::numCols</a>, <a class="el" href="structarm__matrix__instance__q31.html#a63bacac158a821c8cfc06088d251598c">arm_matrix_instance_q31::numRows</a>, <a class="el" href="structarm__matrix__instance__q31.html#a09a64267c0579fef086efc9059741e56">arm_matrix_instance_q31::pData</a>, and <a class="el" href="_a_r_m_2arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>.</p>
</div>
</div>
<a class="anchor" id="ga3657b99a9667945373e520dbac0f4516"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> arm_mat_mult_q15 </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pSrcA</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pSrcB</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="structarm__matrix__instance__q15.html">arm_matrix_instance_q15</a> * </td>
<td class="paramname"><em>pDst</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="arm__math_8h.html#ab5a8fb21a5b3b983d5f54f31614052ea">q15_t</a> *pState </td>
<td class="paramname"><em>CMSIS_UNUSED</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcA</td><td>points to the first input matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcB</td><td>points to the second input matrix structure </td></tr>
<tr><td class="paramdir">[out]</td><td class="paramname">*pDst</td><td>points to output matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pState</td><td>points to the array for storing intermediate results (Unused) </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The function returns either <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.</dd></dl>
<p><b>Scaling and Overflow Behavior:</b></p>
<dl class="section user"><dt></dt><dd>The function is implemented using a 64-bit internal accumulator. The inputs to the multiplications are in 1.15 format and multiplications yield a 2.30 result. The 2.30 intermediate results are accumulated in a 64-bit accumulator in 34.30 format. This approach provides 33 guard bits and there is no risk of overflow. The 34.30 result is then truncated to 34.15 format by discarding the low 15 bits and then saturated to 1.15 format.</dd></dl>
<dl class="section user"><dt></dt><dd>Refer to <code><a class="el" href="group___matrix_mult.html#ga08f37d93a5bfef0c5000dc5e0a411f93" title="Q15 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4.">arm_mat_mult_fast_q15()</a></code> for a faster but less precise version of this function for Cortex-M3 and Cortex-M4. </dd></dl>
<p>References <a class="el" href="arm__math_8h.html#a9de2e0a5785be82866bcb96012282248">__SIMD32</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a7071b92f1f6bc3c5c312a237ea91105b">ARM_MATH_SIZE_MISMATCH</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>, <a class="el" href="structarm__matrix__instance__q15.html#acbbce67ba058d8e1c867c71d57288c97">arm_matrix_instance_q15::numCols</a>, <a class="el" href="structarm__matrix__instance__q15.html#a9bac6ed54be287c4d4f01a1a28be65f5">arm_matrix_instance_q15::numRows</a>, <a class="el" href="structarm__matrix__instance__q15.html#a6da33a5553e634787d0f515cf8d724af">arm_matrix_instance_q15::pData</a>, and <a class="el" href="_a_r_m_2arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>.</p>
</div>
</div>
<a class="anchor" id="ga2ec612a8c2c4916477fb9bc1ab548a6e"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6">arm_status</a> arm_mat_mult_q31 </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pSrcA</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const <a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pSrcB</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="structarm__matrix__instance__q31.html">arm_matrix_instance_q31</a> * </td>
<td class="paramname"><em>pDst</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcA</td><td>points to the first input matrix structure </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">*pSrcB</td><td>points to the second input matrix structure </td></tr>
<tr><td class="paramdir">[out]</td><td class="paramname">*pDst</td><td>points to output matrix structure </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>The function returns either <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.</dd></dl>
<p><b>Scaling and Overflow Behavior:</b></p>
<dl class="section user"><dt></dt><dd>The function is implemented using an internal 64-bit accumulator. The accumulator has a 2.62 format and maintains full precision of the intermediate multiplication results but provides only a single guard bit. There is no saturation on intermediate additions. Thus, if the accumulator overflows it wraps around and distorts the result. The input signals should be scaled down to avoid intermediate overflows. The input is thus scaled down by log2(numColsA) bits to avoid overflows, as a total of numColsA additions are performed internally. The 2.62 accumulator is right shifted by 31 bits and saturated to 1.31 format to yield the final result.</dd></dl>
<dl class="section user"><dt></dt><dd>See <code><a class="el" href="group___matrix_mult.html#ga2785e8c1b785348b0c439b56aaf585a3" title="Q31 matrix multiplication (fast variant) for Cortex-M3 and Cortex-M4.">arm_mat_mult_fast_q31()</a></code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4. </dd></dl>
<p>References <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a7071b92f1f6bc3c5c312a237ea91105b">ARM_MATH_SIZE_MISMATCH</a>, <a class="el" href="arm__math_8h.html#a5e459c6409dfcd2927bb8a57491d7cf6a9f8b2a10bd827fb4600e77d455902eb0">ARM_MATH_SUCCESS</a>, <a class="el" href="arm__math_8h.html#ad7373e53d3c2e1adfeafc8c2e9720b5c">clip_q63_to_q31()</a>, <a class="el" href="structarm__matrix__instance__q31.html#abd161da7614eda927157f18b698074b1">arm_matrix_instance_q31::numCols</a>, <a class="el" href="structarm__matrix__instance__q31.html#a63bacac158a821c8cfc06088d251598c">arm_matrix_instance_q31::numRows</a>, <a class="el" href="structarm__matrix__instance__q31.html#a09a64267c0579fef086efc9059741e56">arm_matrix_instance_q31::pData</a>, and <a class="el" href="_a_r_m_2arm__dotproduct__example__f32_8c.html#a88ccb294236ab22b00310c47164c53c3">status</a>.</p>
</div>
</div>
</div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="footer">Generated on Tue Oct 27 2015 14:35:33 for CMSIS-DSP by ARM Ltd. All rights reserved.
<!--
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.2
-->
</li>
</ul>
</div>
</body>
</html>
|
