| <!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"/> |
| <title>CMSIS DSP Software Library: arm_fir_f32.c Source File</title> |
| <link href="tabs.css" rel="stylesheet" type="text/css"/> |
| <link href="search/search.css" rel="stylesheet" type="text/css"/> |
| <script type="text/javaScript" src="search/search.js"></script> |
| <link href="doxygen.css" rel="stylesheet" type="text/css"/> |
| </head> |
| <body onload='searchBox.OnSelectItem(0);'> |
| <!-- Generated by Doxygen 1.7.2 --> |
| <script type="text/javascript"><!-- |
| var searchBox = new SearchBox("searchBox", "search",false,'Search'); |
| --></script> |
| <div class="navigation" id="top"> |
| <div class="tabs"> |
| <ul class="tablist"> |
| <li><a href="index.html"><span>Main Page</span></a></li> |
| <li><a href="modules.html"><span>Modules</span></a></li> |
| <li><a href="annotated.html"><span>Data Structures</span></a></li> |
| <li class="current"><a href="files.html"><span>Files</span></a></li> |
| <li><a href="examples.html"><span>Examples</span></a></li> |
| <li id="searchli"> |
| <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 class="tabs2"> |
| <ul class="tablist"> |
| <li><a href="files.html"><span>File List</span></a></li> |
| <li><a href="globals.html"><span>Globals</span></a></li> |
| </ul> |
| </div> |
| <div class="header"> |
| <div class="headertitle"> |
| <h1>arm_fir_f32.c</h1> </div> |
| </div> |
| <div class="contents"> |
| <a href="arm__fir__f32_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* ---------------------------------------------------------------------- </span> |
| <a name="l00002"></a>00002 <span class="comment">* Copyright (C) 2010 ARM Limited. All rights reserved. </span> |
| <a name="l00003"></a>00003 <span class="comment">* </span> |
| <a name="l00004"></a>00004 <span class="comment">* $Date: 15. July 2011 </span> |
| <a name="l00005"></a>00005 <span class="comment">* $Revision: V1.0.10 </span> |
| <a name="l00006"></a>00006 <span class="comment">* </span> |
| <a name="l00007"></a>00007 <span class="comment">* Project: CMSIS DSP Library </span> |
| <a name="l00008"></a>00008 <span class="comment">* Title: arm_fir_f32.c </span> |
| <a name="l00009"></a>00009 <span class="comment">* </span> |
| <a name="l00010"></a>00010 <span class="comment">* Description: Floating-point FIR filter processing function. </span> |
| <a name="l00011"></a>00011 <span class="comment">* </span> |
| <a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0</span> |
| <a name="l00013"></a>00013 <span class="comment">* </span> |
| <a name="l00014"></a>00014 <span class="comment">* Version 1.0.10 2011/7/15 </span> |
| <a name="l00015"></a>00015 <span class="comment">* Big Endian support added and Merged M0 and M3/M4 Source code. </span> |
| <a name="l00016"></a>00016 <span class="comment">* </span> |
| <a name="l00017"></a>00017 <span class="comment">* Version 1.0.3 2010/11/29 </span> |
| <a name="l00018"></a>00018 <span class="comment">* Re-organized the CMSIS folders and updated documentation. </span> |
| <a name="l00019"></a>00019 <span class="comment">* </span> |
| <a name="l00020"></a>00020 <span class="comment">* Version 1.0.2 2010/11/11 </span> |
| <a name="l00021"></a>00021 <span class="comment">* Documentation updated. </span> |
| <a name="l00022"></a>00022 <span class="comment">* </span> |
| <a name="l00023"></a>00023 <span class="comment">* Version 1.0.1 2010/10/05 </span> |
| <a name="l00024"></a>00024 <span class="comment">* Production release and review comments incorporated. </span> |
| <a name="l00025"></a>00025 <span class="comment">* </span> |
| <a name="l00026"></a>00026 <span class="comment">* Version 1.0.0 2010/09/20 </span> |
| <a name="l00027"></a>00027 <span class="comment">* Production release and review comments incorporated. </span> |
| <a name="l00028"></a>00028 <span class="comment">* </span> |
| <a name="l00029"></a>00029 <span class="comment">* Version 0.0.5 2010/04/26 </span> |
| <a name="l00030"></a>00030 <span class="comment">* incorporated review comments and updated with latest CMSIS layer </span> |
| <a name="l00031"></a>00031 <span class="comment">* </span> |
| <a name="l00032"></a>00032 <span class="comment">* Version 0.0.3 2010/03/10 </span> |
| <a name="l00033"></a>00033 <span class="comment">* Initial version </span> |
| <a name="l00034"></a>00034 <span class="comment">* -------------------------------------------------------------------- */</span> |
| <a name="l00035"></a>00035 |
| <a name="l00036"></a>00036 <span class="preprocessor">#include "<a class="code" href="arm__math_8h.html">arm_math.h</a>"</span> |
| <a name="l00037"></a>00037 |
| <a name="l00128"></a><a class="code" href="group___f_i_r.html#gae8fb334ea67eb6ecbd31824ddc14cd6a">00128</a> <span class="keywordtype">void</span> <a class="code" href="group___f_i_r.html#gae8fb334ea67eb6ecbd31824ddc14cd6a" title="Processing function for the floating-point FIR filter.">arm_fir_f32</a>( |
| <a name="l00129"></a>00129 <span class="keyword">const</span> <a class="code" href="structarm__fir__instance__f32.html" title="Instance structure for the floating-point FIR filter.">arm_fir_instance_f32</a> * S, |
| <a name="l00130"></a>00130 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> * pSrc, |
| <a name="l00131"></a>00131 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> * pDst, |
| <a name="l00132"></a>00132 uint32_t <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>) |
| <a name="l00133"></a>00133 { |
| <a name="l00134"></a>00134 |
| <a name="l00135"></a>00135 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *pState = S-><a class="code" href="structarm__fir__instance__f32.html#a7afcf4022e8560db9b8fd28b0d090a15">pState</a>; <span class="comment">/* State pointer */</span> |
| <a name="l00136"></a>00136 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *pCoeffs = S-><a class="code" href="structarm__fir__instance__f32.html#a1c9cfca901d5902afeb640f2831488f4">pCoeffs</a>; <span class="comment">/* Coefficient pointer */</span> |
| <a name="l00137"></a>00137 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *pStateCurnt; <span class="comment">/* Points to the current sample of the state */</span> |
| <a name="l00138"></a>00138 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *px, *pb; <span class="comment">/* Temporary pointers for state and coefficient buffers */</span> |
| <a name="l00139"></a>00139 uint32_t numTaps = S-><a class="code" href="structarm__fir__instance__f32.html#a20cf98c92b5323799b7881c9ff4d2f7c">numTaps</a>; <span class="comment">/* Number of filter coefficients in the filter */</span> |
| <a name="l00140"></a>00140 uint32_t i, tapCnt, blkCnt; <span class="comment">/* Loop counters */</span> |
| <a name="l00141"></a>00141 |
| <a name="l00142"></a>00142 |
| <a name="l00143"></a>00143 <span class="preprocessor">#ifndef ARM_MATH_CM0</span> |
| <a name="l00144"></a>00144 <span class="preprocessor"></span> |
| <a name="l00145"></a>00145 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span> |
| <a name="l00146"></a>00146 |
| <a name="l00147"></a>00147 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> acc0, acc1, acc2, acc3; <span class="comment">/* Accumulators */</span> |
| <a name="l00148"></a>00148 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> x0, x1, x2, x3, c0; <span class="comment">/* Temporary variables to hold state and coefficient values */</span> |
| <a name="l00149"></a>00149 |
| <a name="l00150"></a>00150 |
| <a name="l00151"></a>00151 <span class="comment">/* S->pState points to state array which contains previous frame (numTaps - 1) samples */</span> |
| <a name="l00152"></a>00152 <span class="comment">/* pStateCurnt points to the location where the new input data should be written */</span> |
| <a name="l00153"></a>00153 pStateCurnt = &(S-><a class="code" href="structarm__fir__instance__f32.html#a7afcf4022e8560db9b8fd28b0d090a15">pState</a>[(numTaps - 1u)]); |
| <a name="l00154"></a>00154 |
| <a name="l00155"></a>00155 <span class="comment">/* Apply loop unrolling and compute 4 output values simultaneously. </span> |
| <a name="l00156"></a>00156 <span class="comment"> * The variables acc0 ... acc3 hold output values that are being computed: </span> |
| <a name="l00157"></a>00157 <span class="comment"> * </span> |
| <a name="l00158"></a>00158 <span class="comment"> * acc0 = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] </span> |
| <a name="l00159"></a>00159 <span class="comment"> * acc1 = b[numTaps-1] * x[n-numTaps] + b[numTaps-2] * x[n-numTaps-1] + b[numTaps-3] * x[n-numTaps-2] +...+ b[0] * x[1] </span> |
| <a name="l00160"></a>00160 <span class="comment"> * acc2 = b[numTaps-1] * x[n-numTaps+1] + b[numTaps-2] * x[n-numTaps] + b[numTaps-3] * x[n-numTaps-1] +...+ b[0] * x[2] </span> |
| <a name="l00161"></a>00161 <span class="comment"> * acc3 = b[numTaps-1] * x[n-numTaps+2] + b[numTaps-2] * x[n-numTaps+1] + b[numTaps-3] * x[n-numTaps] +...+ b[0] * x[3] </span> |
| <a name="l00162"></a>00162 <span class="comment"> */</span> |
| <a name="l00163"></a>00163 blkCnt = blockSize >> 2; |
| <a name="l00164"></a>00164 |
| <a name="l00165"></a>00165 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 outputs at a time. </span> |
| <a name="l00166"></a>00166 <span class="comment"> ** a second loop below computes the remaining 1 to 3 samples. */</span> |
| <a name="l00167"></a>00167 <span class="keywordflow">while</span>(blkCnt > 0u) |
| <a name="l00168"></a>00168 { |
| <a name="l00169"></a>00169 <span class="comment">/* Copy four new input samples into the state buffer */</span> |
| <a name="l00170"></a>00170 *pStateCurnt++ = *pSrc++; |
| <a name="l00171"></a>00171 *pStateCurnt++ = *pSrc++; |
| <a name="l00172"></a>00172 *pStateCurnt++ = *pSrc++; |
| <a name="l00173"></a>00173 *pStateCurnt++ = *pSrc++; |
| <a name="l00174"></a>00174 |
| <a name="l00175"></a>00175 <span class="comment">/* Set all accumulators to zero */</span> |
| <a name="l00176"></a>00176 acc0 = 0.0f; |
| <a name="l00177"></a>00177 acc1 = 0.0f; |
| <a name="l00178"></a>00178 acc2 = 0.0f; |
| <a name="l00179"></a>00179 acc3 = 0.0f; |
| <a name="l00180"></a>00180 |
| <a name="l00181"></a>00181 <span class="comment">/* Initialize state pointer */</span> |
| <a name="l00182"></a>00182 px = pState; |
| <a name="l00183"></a>00183 |
| <a name="l00184"></a>00184 <span class="comment">/* Initialize coeff pointer */</span> |
| <a name="l00185"></a>00185 pb = (pCoeffs); |
| <a name="l00186"></a>00186 |
| <a name="l00187"></a>00187 <span class="comment">/* Read the first three samples from the state buffer: x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2] */</span> |
| <a name="l00188"></a>00188 x0 = *px++; |
| <a name="l00189"></a>00189 x1 = *px++; |
| <a name="l00190"></a>00190 x2 = *px++; |
| <a name="l00191"></a>00191 |
| <a name="l00192"></a>00192 <span class="comment">/* Loop unrolling. Process 4 taps at a time. */</span> |
| <a name="l00193"></a>00193 tapCnt = numTaps >> 2u; |
| <a name="l00194"></a>00194 |
| <a name="l00195"></a>00195 <span class="comment">/* Loop over the number of taps. Unroll by a factor of 4. </span> |
| <a name="l00196"></a>00196 <span class="comment"> ** Repeat until we've computed numTaps-4 coefficients. */</span> |
| <a name="l00197"></a>00197 <span class="keywordflow">while</span>(tapCnt > 0u) |
| <a name="l00198"></a>00198 { |
| <a name="l00199"></a>00199 <span class="comment">/* Read the b[numTaps-1] coefficient */</span> |
| <a name="l00200"></a>00200 c0 = *(pb++); |
| <a name="l00201"></a>00201 |
| <a name="l00202"></a>00202 <span class="comment">/* Read x[n-numTaps-3] sample */</span> |
| <a name="l00203"></a>00203 x3 = *(px++); |
| <a name="l00204"></a>00204 |
| <a name="l00205"></a>00205 <span class="comment">/* acc0 += b[numTaps-1] * x[n-numTaps] */</span> |
| <a name="l00206"></a>00206 acc0 += x0 * c0; |
| <a name="l00207"></a>00207 |
| <a name="l00208"></a>00208 <span class="comment">/* acc1 += b[numTaps-1] * x[n-numTaps-1] */</span> |
| <a name="l00209"></a>00209 acc1 += x1 * c0; |
| <a name="l00210"></a>00210 |
| <a name="l00211"></a>00211 <span class="comment">/* acc2 += b[numTaps-1] * x[n-numTaps-2] */</span> |
| <a name="l00212"></a>00212 acc2 += x2 * c0; |
| <a name="l00213"></a>00213 |
| <a name="l00214"></a>00214 <span class="comment">/* acc3 += b[numTaps-1] * x[n-numTaps-3] */</span> |
| <a name="l00215"></a>00215 acc3 += x3 * c0; |
| <a name="l00216"></a>00216 |
| <a name="l00217"></a>00217 <span class="comment">/* Read the b[numTaps-2] coefficient */</span> |
| <a name="l00218"></a>00218 c0 = *(pb++); |
| <a name="l00219"></a>00219 |
| <a name="l00220"></a>00220 <span class="comment">/* Read x[n-numTaps-4] sample */</span> |
| <a name="l00221"></a>00221 x0 = *(px++); |
| <a name="l00222"></a>00222 |
| <a name="l00223"></a>00223 <span class="comment">/* Perform the multiply-accumulate */</span> |
| <a name="l00224"></a>00224 acc0 += x1 * c0; |
| <a name="l00225"></a>00225 acc1 += x2 * c0; |
| <a name="l00226"></a>00226 acc2 += x3 * c0; |
| <a name="l00227"></a>00227 acc3 += x0 * c0; |
| <a name="l00228"></a>00228 |
| <a name="l00229"></a>00229 <span class="comment">/* Read the b[numTaps-3] coefficient */</span> |
| <a name="l00230"></a>00230 c0 = *(pb++); |
| <a name="l00231"></a>00231 |
| <a name="l00232"></a>00232 <span class="comment">/* Read x[n-numTaps-5] sample */</span> |
| <a name="l00233"></a>00233 x1 = *(px++); |
| <a name="l00234"></a>00234 |
| <a name="l00235"></a>00235 <span class="comment">/* Perform the multiply-accumulates */</span> |
| <a name="l00236"></a>00236 acc0 += x2 * c0; |
| <a name="l00237"></a>00237 acc1 += x3 * c0; |
| <a name="l00238"></a>00238 acc2 += x0 * c0; |
| <a name="l00239"></a>00239 acc3 += x1 * c0; |
| <a name="l00240"></a>00240 |
| <a name="l00241"></a>00241 <span class="comment">/* Read the b[numTaps-4] coefficient */</span> |
| <a name="l00242"></a>00242 c0 = *(pb++); |
| <a name="l00243"></a>00243 |
| <a name="l00244"></a>00244 <span class="comment">/* Read x[n-numTaps-6] sample */</span> |
| <a name="l00245"></a>00245 x2 = *(px++); |
| <a name="l00246"></a>00246 |
| <a name="l00247"></a>00247 <span class="comment">/* Perform the multiply-accumulates */</span> |
| <a name="l00248"></a>00248 acc0 += x3 * c0; |
| <a name="l00249"></a>00249 acc1 += x0 * c0; |
| <a name="l00250"></a>00250 acc2 += x1 * c0; |
| <a name="l00251"></a>00251 acc3 += x2 * c0; |
| <a name="l00252"></a>00252 |
| <a name="l00253"></a>00253 tapCnt--; |
| <a name="l00254"></a>00254 } |
| <a name="l00255"></a>00255 |
| <a name="l00256"></a>00256 <span class="comment">/* If the filter length is not a multiple of 4, compute the remaining filter taps */</span> |
| <a name="l00257"></a>00257 tapCnt = numTaps % 0x4u; |
| <a name="l00258"></a>00258 |
| <a name="l00259"></a>00259 <span class="keywordflow">while</span>(tapCnt > 0u) |
| <a name="l00260"></a>00260 { |
| <a name="l00261"></a>00261 <span class="comment">/* Read coefficients */</span> |
| <a name="l00262"></a>00262 c0 = *(pb++); |
| <a name="l00263"></a>00263 |
| <a name="l00264"></a>00264 <span class="comment">/* Fetch 1 state variable */</span> |
| <a name="l00265"></a>00265 x3 = *(px++); |
| <a name="l00266"></a>00266 |
| <a name="l00267"></a>00267 <span class="comment">/* Perform the multiply-accumulates */</span> |
| <a name="l00268"></a>00268 acc0 += x0 * c0; |
| <a name="l00269"></a>00269 acc1 += x1 * c0; |
| <a name="l00270"></a>00270 acc2 += x2 * c0; |
| <a name="l00271"></a>00271 acc3 += x3 * c0; |
| <a name="l00272"></a>00272 |
| <a name="l00273"></a>00273 <span class="comment">/* Reuse the present sample states for next sample */</span> |
| <a name="l00274"></a>00274 x0 = x1; |
| <a name="l00275"></a>00275 x1 = x2; |
| <a name="l00276"></a>00276 x2 = x3; |
| <a name="l00277"></a>00277 |
| <a name="l00278"></a>00278 <span class="comment">/* Decrement the loop counter */</span> |
| <a name="l00279"></a>00279 tapCnt--; |
| <a name="l00280"></a>00280 } |
| <a name="l00281"></a>00281 |
| <a name="l00282"></a>00282 <span class="comment">/* Advance the state pointer by 4 to process the next group of 4 samples */</span> |
| <a name="l00283"></a>00283 pState = pState + 4; |
| <a name="l00284"></a>00284 |
| <a name="l00285"></a>00285 <span class="comment">/* The results in the 4 accumulators, store in the destination buffer. */</span> |
| <a name="l00286"></a>00286 *pDst++ = acc0; |
| <a name="l00287"></a>00287 *pDst++ = acc1; |
| <a name="l00288"></a>00288 *pDst++ = acc2; |
| <a name="l00289"></a>00289 *pDst++ = acc3; |
| <a name="l00290"></a>00290 |
| <a name="l00291"></a>00291 blkCnt--; |
| <a name="l00292"></a>00292 } |
| <a name="l00293"></a>00293 |
| <a name="l00294"></a>00294 <span class="comment">/* If the blockSize is not a multiple of 4, compute any remaining output samples here. </span> |
| <a name="l00295"></a>00295 <span class="comment"> ** No loop unrolling is used. */</span> |
| <a name="l00296"></a>00296 blkCnt = blockSize % 0x4u; |
| <a name="l00297"></a>00297 |
| <a name="l00298"></a>00298 <span class="keywordflow">while</span>(blkCnt > 0u) |
| <a name="l00299"></a>00299 { |
| <a name="l00300"></a>00300 <span class="comment">/* Copy one sample at a time into state buffer */</span> |
| <a name="l00301"></a>00301 *pStateCurnt++ = *pSrc++; |
| <a name="l00302"></a>00302 |
| <a name="l00303"></a>00303 <span class="comment">/* Set the accumulator to zero */</span> |
| <a name="l00304"></a>00304 acc0 = 0.0f; |
| <a name="l00305"></a>00305 |
| <a name="l00306"></a>00306 <span class="comment">/* Initialize state pointer */</span> |
| <a name="l00307"></a>00307 px = pState; |
| <a name="l00308"></a>00308 |
| <a name="l00309"></a>00309 <span class="comment">/* Initialize Coefficient pointer */</span> |
| <a name="l00310"></a>00310 pb = (pCoeffs); |
| <a name="l00311"></a>00311 |
| <a name="l00312"></a>00312 i = numTaps; |
| <a name="l00313"></a>00313 |
| <a name="l00314"></a>00314 <span class="comment">/* Perform the multiply-accumulates */</span> |
| <a name="l00315"></a>00315 <span class="keywordflow">do</span> |
| <a name="l00316"></a>00316 { |
| <a name="l00317"></a>00317 acc0 += *px++ * *pb++; |
| <a name="l00318"></a>00318 i--; |
| <a name="l00319"></a>00319 |
| <a name="l00320"></a>00320 } <span class="keywordflow">while</span>(i > 0u); |
| <a name="l00321"></a>00321 |
| <a name="l00322"></a>00322 <span class="comment">/* The result is store in the destination buffer. */</span> |
| <a name="l00323"></a>00323 *pDst++ = acc0; |
| <a name="l00324"></a>00324 |
| <a name="l00325"></a>00325 <span class="comment">/* Advance state pointer by 1 for the next sample */</span> |
| <a name="l00326"></a>00326 pState = pState + 1; |
| <a name="l00327"></a>00327 |
| <a name="l00328"></a>00328 blkCnt--; |
| <a name="l00329"></a>00329 } |
| <a name="l00330"></a>00330 |
| <a name="l00331"></a>00331 <span class="comment">/* Processing is complete. </span> |
| <a name="l00332"></a>00332 <span class="comment"> ** Now copy the last numTaps - 1 samples to the satrt of the state buffer. </span> |
| <a name="l00333"></a>00333 <span class="comment"> ** This prepares the state buffer for the next function call. */</span> |
| <a name="l00334"></a>00334 |
| <a name="l00335"></a>00335 <span class="comment">/* Points to the start of the state buffer */</span> |
| <a name="l00336"></a>00336 pStateCurnt = S-><a class="code" href="structarm__fir__instance__f32.html#a7afcf4022e8560db9b8fd28b0d090a15">pState</a>; |
| <a name="l00337"></a>00337 |
| <a name="l00338"></a>00338 tapCnt = (numTaps - 1u) >> 2u; |
| <a name="l00339"></a>00339 |
| <a name="l00340"></a>00340 <span class="comment">/* copy data */</span> |
| <a name="l00341"></a>00341 <span class="keywordflow">while</span>(tapCnt > 0u) |
| <a name="l00342"></a>00342 { |
| <a name="l00343"></a>00343 *pStateCurnt++ = *pState++; |
| <a name="l00344"></a>00344 *pStateCurnt++ = *pState++; |
| <a name="l00345"></a>00345 *pStateCurnt++ = *pState++; |
| <a name="l00346"></a>00346 *pStateCurnt++ = *pState++; |
| <a name="l00347"></a>00347 |
| <a name="l00348"></a>00348 <span class="comment">/* Decrement the loop counter */</span> |
| <a name="l00349"></a>00349 tapCnt--; |
| <a name="l00350"></a>00350 } |
| <a name="l00351"></a>00351 |
| <a name="l00352"></a>00352 <span class="comment">/* Calculate remaining number of copies */</span> |
| <a name="l00353"></a>00353 tapCnt = (numTaps - 1u) % 0x4u; |
| <a name="l00354"></a>00354 |
| <a name="l00355"></a>00355 <span class="comment">/* Copy the remaining q31_t data */</span> |
| <a name="l00356"></a>00356 <span class="keywordflow">while</span>(tapCnt > 0u) |
| <a name="l00357"></a>00357 { |
| <a name="l00358"></a>00358 *pStateCurnt++ = *pState++; |
| <a name="l00359"></a>00359 |
| <a name="l00360"></a>00360 <span class="comment">/* Decrement the loop counter */</span> |
| <a name="l00361"></a>00361 tapCnt--; |
| <a name="l00362"></a>00362 } |
| <a name="l00363"></a>00363 |
| <a name="l00364"></a>00364 <span class="preprocessor">#else</span> |
| <a name="l00365"></a>00365 <span class="preprocessor"></span> |
| <a name="l00366"></a>00366 <span class="comment">/* Run the below code for Cortex-M0 */</span> |
| <a name="l00367"></a>00367 |
| <a name="l00368"></a>00368 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> acc; |
| <a name="l00369"></a>00369 |
| <a name="l00370"></a>00370 <span class="comment">/* S->pState points to state array which contains previous frame (numTaps - 1) samples */</span> |
| <a name="l00371"></a>00371 <span class="comment">/* pStateCurnt points to the location where the new input data should be written */</span> |
| <a name="l00372"></a>00372 pStateCurnt = &(S-><a class="code" href="structarm__fir__instance__f32.html#a7afcf4022e8560db9b8fd28b0d090a15">pState</a>[(numTaps - 1u)]); |
| <a name="l00373"></a>00373 |
| <a name="l00374"></a>00374 <span class="comment">/* Initialize blkCnt with blockSize */</span> |
| <a name="l00375"></a>00375 blkCnt = <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>; |
| <a name="l00376"></a>00376 |
| <a name="l00377"></a>00377 <span class="keywordflow">while</span>(blkCnt > 0u) |
| <a name="l00378"></a>00378 { |
| <a name="l00379"></a>00379 <span class="comment">/* Copy one sample at a time into state buffer */</span> |
| <a name="l00380"></a>00380 *pStateCurnt++ = *pSrc++; |
| <a name="l00381"></a>00381 |
| <a name="l00382"></a>00382 <span class="comment">/* Set the accumulator to zero */</span> |
| <a name="l00383"></a>00383 acc = 0.0f; |
| <a name="l00384"></a>00384 |
| <a name="l00385"></a>00385 <span class="comment">/* Initialize state pointer */</span> |
| <a name="l00386"></a>00386 px = pState; |
| <a name="l00387"></a>00387 |
| <a name="l00388"></a>00388 <span class="comment">/* Initialize Coefficient pointer */</span> |
| <a name="l00389"></a>00389 pb = pCoeffs; |
| <a name="l00390"></a>00390 |
| <a name="l00391"></a>00391 i = numTaps; |
| <a name="l00392"></a>00392 |
| <a name="l00393"></a>00393 <span class="comment">/* Perform the multiply-accumulates */</span> |
| <a name="l00394"></a>00394 <span class="keywordflow">do</span> |
| <a name="l00395"></a>00395 { |
| <a name="l00396"></a>00396 <span class="comment">/* acc = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] */</span> |
| <a name="l00397"></a>00397 acc += *px++ * *pb++; |
| <a name="l00398"></a>00398 i--; |
| <a name="l00399"></a>00399 |
| <a name="l00400"></a>00400 } <span class="keywordflow">while</span>(i > 0u); |
| <a name="l00401"></a>00401 |
| <a name="l00402"></a>00402 <span class="comment">/* The result is store in the destination buffer. */</span> |
| <a name="l00403"></a>00403 *pDst++ = acc; |
| <a name="l00404"></a>00404 |
| <a name="l00405"></a>00405 <span class="comment">/* Advance state pointer by 1 for the next sample */</span> |
| <a name="l00406"></a>00406 pState = pState + 1; |
| <a name="l00407"></a>00407 |
| <a name="l00408"></a>00408 blkCnt--; |
| <a name="l00409"></a>00409 } |
| <a name="l00410"></a>00410 |
| <a name="l00411"></a>00411 <span class="comment">/* Processing is complete. </span> |
| <a name="l00412"></a>00412 <span class="comment"> ** Now copy the last numTaps - 1 samples to the starting of the state buffer. </span> |
| <a name="l00413"></a>00413 <span class="comment"> ** This prepares the state buffer for the next function call. */</span> |
| <a name="l00414"></a>00414 |
| <a name="l00415"></a>00415 <span class="comment">/* Points to the start of the state buffer */</span> |
| <a name="l00416"></a>00416 pStateCurnt = S-><a class="code" href="structarm__fir__instance__f32.html#a7afcf4022e8560db9b8fd28b0d090a15">pState</a>; |
| <a name="l00417"></a>00417 |
| <a name="l00418"></a>00418 <span class="comment">/* Copy numTaps number of values */</span> |
| <a name="l00419"></a>00419 tapCnt = numTaps - 1u; |
| <a name="l00420"></a>00420 |
| <a name="l00421"></a>00421 <span class="comment">/* Copy data */</span> |
| <a name="l00422"></a>00422 <span class="keywordflow">while</span>(tapCnt > 0u) |
| <a name="l00423"></a>00423 { |
| <a name="l00424"></a>00424 *pStateCurnt++ = *pState++; |
| <a name="l00425"></a>00425 |
| <a name="l00426"></a>00426 <span class="comment">/* Decrement the loop counter */</span> |
| <a name="l00427"></a>00427 tapCnt--; |
| <a name="l00428"></a>00428 } |
| <a name="l00429"></a>00429 |
| <a name="l00430"></a>00430 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span> |
| <a name="l00431"></a>00431 |
| <a name="l00432"></a>00432 } |
| <a name="l00433"></a>00433 |
| </pre></div></div> |
| </div> |
| <!--- 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>Defines</a></div> |
| |
| <!-- iframe showing the search results (closed by default) --> |
| <div id="MSearchResultsWindow"> |
| <iframe src="" frameborder="0" |
| name="MSearchResults" id="MSearchResults"> |
| </iframe> |
| </div> |
| |
| <hr class="footer"/><address class="footer"><small>Generated on Fri Jul 15 2011 13:16:16 for CMSIS DSP Software Library by  |
| <a href="http://www.doxygen.org/index.html"> |
| <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.7.2 </small></address> |
| </body> |
| </html> |
