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49 <div class="headertitle">
50 <h1>arm_fir_lattice_f32.c</h1> </div>
52 <div class="contents">
53 <a href="arm__fir__lattice__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>
54 <a name="l00002"></a>00002 <span class="comment">* Copyright (C) 2010 ARM Limited. All rights reserved. </span>
55 <a name="l00003"></a>00003 <span class="comment">* </span>
56 <a name="l00004"></a>00004 <span class="comment">* $Date: 15. July 2011 </span>
57 <a name="l00005"></a>00005 <span class="comment">* $Revision: V1.0.10 </span>
58 <a name="l00006"></a>00006 <span class="comment">* </span>
59 <a name="l00007"></a>00007 <span class="comment">* Project: CMSIS DSP Library </span>
60 <a name="l00008"></a>00008 <span class="comment">* Title: arm_fir_lattice_f32.c </span>
61 <a name="l00009"></a>00009 <span class="comment">* </span>
62 <a name="l00010"></a>00010 <span class="comment">* Description: Processing function for the floating-point FIR Lattice filter. </span>
63 <a name="l00011"></a>00011 <span class="comment">* </span>
64 <a name="l00012"></a>00012 <span class="comment">* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0</span>
65 <a name="l00013"></a>00013 <span class="comment">* </span>
66 <a name="l00014"></a>00014 <span class="comment">* Version 1.0.10 2011/7/15 </span>
67 <a name="l00015"></a>00015 <span class="comment">* Big Endian support added and Merged M0 and M3/M4 Source code. </span>
68 <a name="l00016"></a>00016 <span class="comment">* </span>
69 <a name="l00017"></a>00017 <span class="comment">* Version 1.0.3 2010/11/29 </span>
70 <a name="l00018"></a>00018 <span class="comment">* Re-organized the CMSIS folders and updated documentation. </span>
71 <a name="l00019"></a>00019 <span class="comment">* </span>
72 <a name="l00020"></a>00020 <span class="comment">* Version 1.0.2 2010/11/11 </span>
73 <a name="l00021"></a>00021 <span class="comment">* Documentation updated. </span>
74 <a name="l00022"></a>00022 <span class="comment">* </span>
75 <a name="l00023"></a>00023 <span class="comment">* Version 1.0.1 2010/10/05 </span>
76 <a name="l00024"></a>00024 <span class="comment">* Production release and review comments incorporated. </span>
77 <a name="l00025"></a>00025 <span class="comment">* </span>
78 <a name="l00026"></a>00026 <span class="comment">* Version 1.0.0 2010/09/20 </span>
79 <a name="l00027"></a>00027 <span class="comment">* Production release and review comments incorporated </span>
80 <a name="l00028"></a>00028 <span class="comment">* </span>
81 <a name="l00029"></a>00029 <span class="comment">* Version 0.0.7 2010/06/10 </span>
82 <a name="l00030"></a>00030 <span class="comment">* Misra-C changes done </span>
83 <a name="l00031"></a>00031 <span class="comment">* -------------------------------------------------------------------- */</span>
84 <a name="l00032"></a>00032
85 <a name="l00033"></a>00033 <span class="preprocessor">#include "<a class="code" href="arm__math_8h.html">arm_math.h</a>"</span>
86 <a name="l00034"></a>00034
87 <a name="l00121"></a><a class="code" href="group___f_i_r___lattice.html#gae63a45a63a11a65f2eae8b8b1fe370a8">00121</a> <span class="keywordtype">void</span> <a class="code" href="group___f_i_r___lattice.html#gae63a45a63a11a65f2eae8b8b1fe370a8" title="Processing function for the floating-point FIR lattice filter.">arm_fir_lattice_f32</a>(
88 <a name="l00122"></a>00122 <span class="keyword">const</span> <a class="code" href="structarm__fir__lattice__instance__f32.html" title="Instance structure for the floating-point FIR lattice filter.">arm_fir_lattice_instance_f32</a> * S,
89 <a name="l00123"></a>00123 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> * pSrc,
90 <a name="l00124"></a>00124 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> * pDst,
91 <a name="l00125"></a>00125 uint32_t <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>)
92 <a name="l00126"></a>00126 {
93 <a name="l00127"></a>00127 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *pState; <span class="comment">/* State pointer */</span>
94 <a name="l00128"></a>00128 <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__lattice__instance__f32.html#a33bf5948c947f9ef80a99717cb0a0a43">pCoeffs</a>; <span class="comment">/* Coefficient pointer */</span>
95 <a name="l00129"></a>00129 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *px; <span class="comment">/* temporary state pointer */</span>
96 <a name="l00130"></a>00130 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> *pk; <span class="comment">/* temporary coefficient pointer */</span>
97 <a name="l00131"></a>00131
98 <a name="l00132"></a>00132
99 <a name="l00133"></a>00133 <span class="preprocessor">#ifndef ARM_MATH_CM0</span>
100 <a name="l00134"></a>00134 <span class="preprocessor"></span>
101 <a name="l00135"></a>00135 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span>
102 <a name="l00136"></a>00136
103 <a name="l00137"></a>00137 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> fcurr1, fnext1, gcurr1, gnext1; <span class="comment">/* temporary variables for first sample in loop unrolling */</span>
104 <a name="l00138"></a>00138 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> fcurr2, fnext2, gnext2; <span class="comment">/* temporary variables for second sample in loop unrolling */</span>
105 <a name="l00139"></a>00139 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> fcurr3, fnext3, gnext3; <span class="comment">/* temporary variables for third sample in loop unrolling */</span>
106 <a name="l00140"></a>00140 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> fcurr4, fnext4, gnext4; <span class="comment">/* temporary variables for fourth sample in loop unrolling */</span>
107 <a name="l00141"></a>00141 uint32_t numStages = S-><a class="code" href="structarm__fir__lattice__instance__f32.html#ad369bd9997a250f195254df37408a38f">numStages</a>; <span class="comment">/* Number of stages in the filter */</span>
108 <a name="l00142"></a>00142 uint32_t blkCnt, stageCnt; <span class="comment">/* temporary variables for counts */</span>
109 <a name="l00143"></a>00143
110 <a name="l00144"></a>00144 gcurr1 = 0.0f;
111 <a name="l00145"></a>00145 pState = &S-><a class="code" href="structarm__fir__lattice__instance__f32.html#ae348884a1ba9b83fadccd5da640cbcaf">pState</a>[0];
112 <a name="l00146"></a>00146
113 <a name="l00147"></a>00147 blkCnt = blockSize >> 2;
114 <a name="l00148"></a>00148
115 <a name="l00149"></a>00149 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 outputs at a time. </span>
116 <a name="l00150"></a>00150 <span class="comment"> a second loop below computes the remaining 1 to 3 samples. */</span>
117 <a name="l00151"></a>00151 <span class="keywordflow">while</span>(blkCnt > 0u)
118 <a name="l00152"></a>00152 {
119 <a name="l00153"></a>00153
120 <a name="l00154"></a>00154 <span class="comment">/* Read two samples from input buffer */</span>
121 <a name="l00155"></a>00155 <span class="comment">/* f0(n) = x(n) */</span>
122 <a name="l00156"></a>00156 fcurr1 = *pSrc++;
123 <a name="l00157"></a>00157 fcurr2 = *pSrc++;
124 <a name="l00158"></a>00158
125 <a name="l00159"></a>00159 <span class="comment">/* Initialize coeff pointer */</span>
126 <a name="l00160"></a>00160 pk = (pCoeffs);
127 <a name="l00161"></a>00161
128 <a name="l00162"></a>00162 <span class="comment">/* Initialize state pointer */</span>
129 <a name="l00163"></a>00163 px = pState;
130 <a name="l00164"></a>00164
131 <a name="l00165"></a>00165 <span class="comment">/* Read g0(n-1) from state */</span>
132 <a name="l00166"></a>00166 gcurr1 = *px;
133 <a name="l00167"></a>00167
134 <a name="l00168"></a>00168 <span class="comment">/* Process first sample for first tap */</span>
135 <a name="l00169"></a>00169 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
136 <a name="l00170"></a>00170 fnext1 = fcurr1 + ((*pk) * gcurr1);
137 <a name="l00171"></a>00171 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
138 <a name="l00172"></a>00172 gnext1 = (fcurr1 * (*pk)) + gcurr1;
139 <a name="l00173"></a>00173
140 <a name="l00174"></a>00174 <span class="comment">/* Process second sample for first tap */</span>
141 <a name="l00175"></a>00175 <span class="comment">/* for sample 2 processing */</span>
142 <a name="l00176"></a>00176 fnext2 = fcurr2 + ((*pk) * fcurr1);
143 <a name="l00177"></a>00177 gnext2 = (fcurr2 * (*pk)) + fcurr1;
144 <a name="l00178"></a>00178
145 <a name="l00179"></a>00179 <span class="comment">/* Read next two samples from input buffer */</span>
146 <a name="l00180"></a>00180 <span class="comment">/* f0(n+2) = x(n+2) */</span>
147 <a name="l00181"></a>00181 fcurr3 = *pSrc++;
148 <a name="l00182"></a>00182 fcurr4 = *pSrc++;
149 <a name="l00183"></a>00183
150 <a name="l00184"></a>00184 <span class="comment">/* Copy only last input samples into the state buffer </span>
151 <a name="l00185"></a>00185 <span class="comment"> which will be used for next four samples processing */</span>
152 <a name="l00186"></a>00186 *px++ = fcurr4;
153 <a name="l00187"></a>00187
154 <a name="l00188"></a>00188 <span class="comment">/* Process third sample for first tap */</span>
155 <a name="l00189"></a>00189 fnext3 = fcurr3 + ((*pk) * fcurr2);
156 <a name="l00190"></a>00190 gnext3 = (fcurr3 * (*pk)) + fcurr2;
157 <a name="l00191"></a>00191
158 <a name="l00192"></a>00192 <span class="comment">/* Process fourth sample for first tap */</span>
159 <a name="l00193"></a>00193 fnext4 = fcurr4 + ((*pk) * fcurr3);
160 <a name="l00194"></a>00194 gnext4 = (fcurr4 * (*pk++)) + fcurr3;
161 <a name="l00195"></a>00195
162 <a name="l00196"></a>00196 <span class="comment">/* Update of f values for next coefficient set processing */</span>
163 <a name="l00197"></a>00197 fcurr1 = fnext1;
164 <a name="l00198"></a>00198 fcurr2 = fnext2;
165 <a name="l00199"></a>00199 fcurr3 = fnext3;
166 <a name="l00200"></a>00200 fcurr4 = fnext4;
167 <a name="l00201"></a>00201
168 <a name="l00202"></a>00202 <span class="comment">/* Loop unrolling. Process 4 taps at a time . */</span>
169 <a name="l00203"></a>00203 stageCnt = (numStages - 1u) >> 2u;
170 <a name="l00204"></a>00204
171 <a name="l00205"></a>00205 <span class="comment">/* Loop over the number of taps. Unroll by a factor of 4. </span>
172 <a name="l00206"></a>00206 <span class="comment"> ** Repeat until we've computed numStages-3 coefficients. */</span>
173 <a name="l00207"></a>00207
174 <a name="l00208"></a>00208 <span class="comment">/* Process 2nd, 3rd, 4th and 5th taps ... here */</span>
175 <a name="l00209"></a>00209 <span class="keywordflow">while</span>(stageCnt > 0u)
176 <a name="l00210"></a>00210 {
177 <a name="l00211"></a>00211 <span class="comment">/* Read g1(n-1), g3(n-1) .... from state */</span>
178 <a name="l00212"></a>00212 gcurr1 = *px;
179 <a name="l00213"></a>00213
180 <a name="l00214"></a>00214 <span class="comment">/* save g1(n) in state buffer */</span>
181 <a name="l00215"></a>00215 *px++ = gnext4;
182 <a name="l00216"></a>00216
183 <a name="l00217"></a>00217 <span class="comment">/* Process first sample for 2nd, 6th .. tap */</span>
184 <a name="l00218"></a>00218 <span class="comment">/* Sample processing for K2, K6.... */</span>
185 <a name="l00219"></a>00219 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
186 <a name="l00220"></a>00220 fnext1 = fcurr1 + ((*pk) * gcurr1);
187 <a name="l00221"></a>00221 <span class="comment">/* Process second sample for 2nd, 6th .. tap */</span>
188 <a name="l00222"></a>00222 <span class="comment">/* for sample 2 processing */</span>
189 <a name="l00223"></a>00223 fnext2 = fcurr2 + ((*pk) * gnext1);
190 <a name="l00224"></a>00224 <span class="comment">/* Process third sample for 2nd, 6th .. tap */</span>
191 <a name="l00225"></a>00225 fnext3 = fcurr3 + ((*pk) * gnext2);
192 <a name="l00226"></a>00226 <span class="comment">/* Process fourth sample for 2nd, 6th .. tap */</span>
193 <a name="l00227"></a>00227 fnext4 = fcurr4 + ((*pk) * gnext3);
194 <a name="l00228"></a>00228
195 <a name="l00229"></a>00229 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
196 <a name="l00230"></a>00230 <span class="comment">/* Calculation of state values for next stage */</span>
197 <a name="l00231"></a>00231 gnext4 = (fcurr4 * (*pk)) + gnext3;
198 <a name="l00232"></a>00232 gnext3 = (fcurr3 * (*pk)) + gnext2;
199 <a name="l00233"></a>00233 gnext2 = (fcurr2 * (*pk)) + gnext1;
200 <a name="l00234"></a>00234 gnext1 = (fcurr1 * (*pk++)) + gcurr1;
201 <a name="l00235"></a>00235
202 <a name="l00236"></a>00236
203 <a name="l00237"></a>00237 <span class="comment">/* Read g2(n-1), g4(n-1) .... from state */</span>
204 <a name="l00238"></a>00238 gcurr1 = *px;
205 <a name="l00239"></a>00239
206 <a name="l00240"></a>00240 <span class="comment">/* save g2(n) in state buffer */</span>
207 <a name="l00241"></a>00241 *px++ = gnext4;
208 <a name="l00242"></a>00242
209 <a name="l00243"></a>00243 <span class="comment">/* Sample processing for K3, K7.... */</span>
210 <a name="l00244"></a>00244 <span class="comment">/* Process first sample for 3rd, 7th .. tap */</span>
211 <a name="l00245"></a>00245 <span class="comment">/* f3(n) = f2(n) + K3 * g2(n-1) */</span>
212 <a name="l00246"></a>00246 fcurr1 = fnext1 + ((*pk) * gcurr1);
213 <a name="l00247"></a>00247 <span class="comment">/* Process second sample for 3rd, 7th .. tap */</span>
214 <a name="l00248"></a>00248 fcurr2 = fnext2 + ((*pk) * gnext1);
215 <a name="l00249"></a>00249 <span class="comment">/* Process third sample for 3rd, 7th .. tap */</span>
216 <a name="l00250"></a>00250 fcurr3 = fnext3 + ((*pk) * gnext2);
217 <a name="l00251"></a>00251 <span class="comment">/* Process fourth sample for 3rd, 7th .. tap */</span>
218 <a name="l00252"></a>00252 fcurr4 = fnext4 + ((*pk) * gnext3);
219 <a name="l00253"></a>00253
220 <a name="l00254"></a>00254 <span class="comment">/* Calculation of state values for next stage */</span>
221 <a name="l00255"></a>00255 <span class="comment">/* g3(n) = f2(n) * K3 + g2(n-1) */</span>
222 <a name="l00256"></a>00256 gnext4 = (fnext4 * (*pk)) + gnext3;
223 <a name="l00257"></a>00257 gnext3 = (fnext3 * (*pk)) + gnext2;
224 <a name="l00258"></a>00258 gnext2 = (fnext2 * (*pk)) + gnext1;
225 <a name="l00259"></a>00259 gnext1 = (fnext1 * (*pk++)) + gcurr1;
226 <a name="l00260"></a>00260
227 <a name="l00261"></a>00261
228 <a name="l00262"></a>00262 <span class="comment">/* Read g1(n-1), g3(n-1) .... from state */</span>
229 <a name="l00263"></a>00263 gcurr1 = *px;
230 <a name="l00264"></a>00264
231 <a name="l00265"></a>00265 <span class="comment">/* save g3(n) in state buffer */</span>
232 <a name="l00266"></a>00266 *px++ = gnext4;
233 <a name="l00267"></a>00267
234 <a name="l00268"></a>00268 <span class="comment">/* Sample processing for K4, K8.... */</span>
235 <a name="l00269"></a>00269 <span class="comment">/* Process first sample for 4th, 8th .. tap */</span>
236 <a name="l00270"></a>00270 <span class="comment">/* f4(n) = f3(n) + K4 * g3(n-1) */</span>
237 <a name="l00271"></a>00271 fnext1 = fcurr1 + ((*pk) * gcurr1);
238 <a name="l00272"></a>00272 <span class="comment">/* Process second sample for 4th, 8th .. tap */</span>
239 <a name="l00273"></a>00273 <span class="comment">/* for sample 2 processing */</span>
240 <a name="l00274"></a>00274 fnext2 = fcurr2 + ((*pk) * gnext1);
241 <a name="l00275"></a>00275 <span class="comment">/* Process third sample for 4th, 8th .. tap */</span>
242 <a name="l00276"></a>00276 fnext3 = fcurr3 + ((*pk) * gnext2);
243 <a name="l00277"></a>00277 <span class="comment">/* Process fourth sample for 4th, 8th .. tap */</span>
244 <a name="l00278"></a>00278 fnext4 = fcurr4 + ((*pk) * gnext3);
245 <a name="l00279"></a>00279
246 <a name="l00280"></a>00280 <span class="comment">/* g4(n) = f3(n) * K4 + g3(n-1) */</span>
247 <a name="l00281"></a>00281 <span class="comment">/* Calculation of state values for next stage */</span>
248 <a name="l00282"></a>00282 gnext4 = (fcurr4 * (*pk)) + gnext3;
249 <a name="l00283"></a>00283 gnext3 = (fcurr3 * (*pk)) + gnext2;
250 <a name="l00284"></a>00284 gnext2 = (fcurr2 * (*pk)) + gnext1;
251 <a name="l00285"></a>00285 gnext1 = (fcurr1 * (*pk++)) + gcurr1;
252 <a name="l00286"></a>00286
253 <a name="l00287"></a>00287 <span class="comment">/* Read g2(n-1), g4(n-1) .... from state */</span>
254 <a name="l00288"></a>00288 gcurr1 = *px;
255 <a name="l00289"></a>00289
256 <a name="l00290"></a>00290 <span class="comment">/* save g4(n) in state buffer */</span>
257 <a name="l00291"></a>00291 *px++ = gnext4;
258 <a name="l00292"></a>00292
259 <a name="l00293"></a>00293 <span class="comment">/* Sample processing for K5, K9.... */</span>
260 <a name="l00294"></a>00294 <span class="comment">/* Process first sample for 5th, 9th .. tap */</span>
261 <a name="l00295"></a>00295 <span class="comment">/* f5(n) = f4(n) + K5 * g4(n-1) */</span>
262 <a name="l00296"></a>00296 fcurr1 = fnext1 + ((*pk) * gcurr1);
263 <a name="l00297"></a>00297 <span class="comment">/* Process second sample for 5th, 9th .. tap */</span>
264 <a name="l00298"></a>00298 fcurr2 = fnext2 + ((*pk) * gnext1);
265 <a name="l00299"></a>00299 <span class="comment">/* Process third sample for 5th, 9th .. tap */</span>
266 <a name="l00300"></a>00300 fcurr3 = fnext3 + ((*pk) * gnext2);
267 <a name="l00301"></a>00301 <span class="comment">/* Process fourth sample for 5th, 9th .. tap */</span>
268 <a name="l00302"></a>00302 fcurr4 = fnext4 + ((*pk) * gnext3);
269 <a name="l00303"></a>00303
270 <a name="l00304"></a>00304 <span class="comment">/* Calculation of state values for next stage */</span>
271 <a name="l00305"></a>00305 <span class="comment">/* g5(n) = f4(n) * K5 + g4(n-1) */</span>
272 <a name="l00306"></a>00306 gnext4 = (fnext4 * (*pk)) + gnext3;
273 <a name="l00307"></a>00307 gnext3 = (fnext3 * (*pk)) + gnext2;
274 <a name="l00308"></a>00308 gnext2 = (fnext2 * (*pk)) + gnext1;
275 <a name="l00309"></a>00309 gnext1 = (fnext1 * (*pk++)) + gcurr1;
276 <a name="l00310"></a>00310
277 <a name="l00311"></a>00311 stageCnt--;
278 <a name="l00312"></a>00312 }
279 <a name="l00313"></a>00313
280 <a name="l00314"></a>00314 <span class="comment">/* If the (filter length -1) is not a multiple of 4, compute the remaining filter taps */</span>
281 <a name="l00315"></a>00315 stageCnt = (numStages - 1u) % 0x4u;
282 <a name="l00316"></a>00316
283 <a name="l00317"></a>00317 <span class="keywordflow">while</span>(stageCnt > 0u)
284 <a name="l00318"></a>00318 {
285 <a name="l00319"></a>00319 gcurr1 = *px;
286 <a name="l00320"></a>00320
287 <a name="l00321"></a>00321 <span class="comment">/* save g value in state buffer */</span>
288 <a name="l00322"></a>00322 *px++ = gnext4;
289 <a name="l00323"></a>00323
290 <a name="l00324"></a>00324 <span class="comment">/* Process four samples for last three taps here */</span>
291 <a name="l00325"></a>00325 fnext1 = fcurr1 + ((*pk) * gcurr1);
292 <a name="l00326"></a>00326 fnext2 = fcurr2 + ((*pk) * gnext1);
293 <a name="l00327"></a>00327 fnext3 = fcurr3 + ((*pk) * gnext2);
294 <a name="l00328"></a>00328 fnext4 = fcurr4 + ((*pk) * gnext3);
295 <a name="l00329"></a>00329
296 <a name="l00330"></a>00330 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
297 <a name="l00331"></a>00331 gnext4 = (fcurr4 * (*pk)) + gnext3;
298 <a name="l00332"></a>00332 gnext3 = (fcurr3 * (*pk)) + gnext2;
299 <a name="l00333"></a>00333 gnext2 = (fcurr2 * (*pk)) + gnext1;
300 <a name="l00334"></a>00334 gnext1 = (fcurr1 * (*pk++)) + gcurr1;
301 <a name="l00335"></a>00335
302 <a name="l00336"></a>00336 <span class="comment">/* Update of f values for next coefficient set processing */</span>
303 <a name="l00337"></a>00337 fcurr1 = fnext1;
304 <a name="l00338"></a>00338 fcurr2 = fnext2;
305 <a name="l00339"></a>00339 fcurr3 = fnext3;
306 <a name="l00340"></a>00340 fcurr4 = fnext4;
307 <a name="l00341"></a>00341
308 <a name="l00342"></a>00342 stageCnt--;
309 <a name="l00343"></a>00343
310 <a name="l00344"></a>00344 }
311 <a name="l00345"></a>00345
312 <a name="l00346"></a>00346 <span class="comment">/* The results in the 4 accumulators, store in the destination buffer. */</span>
313 <a name="l00347"></a>00347 <span class="comment">/* y(n) = fN(n) */</span>
314 <a name="l00348"></a>00348 *pDst++ = fcurr1;
315 <a name="l00349"></a>00349 *pDst++ = fcurr2;
316 <a name="l00350"></a>00350 *pDst++ = fcurr3;
317 <a name="l00351"></a>00351 *pDst++ = fcurr4;
318 <a name="l00352"></a>00352
319 <a name="l00353"></a>00353 blkCnt--;
320 <a name="l00354"></a>00354 }
321 <a name="l00355"></a>00355
322 <a name="l00356"></a>00356 <span class="comment">/* If the blockSize is not a multiple of 4, compute any remaining output samples here. </span>
323 <a name="l00357"></a>00357 <span class="comment"> ** No loop unrolling is used. */</span>
324 <a name="l00358"></a>00358 blkCnt = blockSize % 0x4u;
325 <a name="l00359"></a>00359
326 <a name="l00360"></a>00360 <span class="keywordflow">while</span>(blkCnt > 0u)
327 <a name="l00361"></a>00361 {
328 <a name="l00362"></a>00362 <span class="comment">/* f0(n) = x(n) */</span>
329 <a name="l00363"></a>00363 fcurr1 = *pSrc++;
330 <a name="l00364"></a>00364
331 <a name="l00365"></a>00365 <span class="comment">/* Initialize coeff pointer */</span>
332 <a name="l00366"></a>00366 pk = (pCoeffs);
333 <a name="l00367"></a>00367
334 <a name="l00368"></a>00368 <span class="comment">/* Initialize state pointer */</span>
335 <a name="l00369"></a>00369 px = pState;
336 <a name="l00370"></a>00370
337 <a name="l00371"></a>00371 <span class="comment">/* read g2(n) from state buffer */</span>
338 <a name="l00372"></a>00372 gcurr1 = *px;
339 <a name="l00373"></a>00373
340 <a name="l00374"></a>00374 <span class="comment">/* for sample 1 processing */</span>
341 <a name="l00375"></a>00375 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
342 <a name="l00376"></a>00376 fnext1 = fcurr1 + ((*pk) * gcurr1);
343 <a name="l00377"></a>00377 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
344 <a name="l00378"></a>00378 gnext1 = (fcurr1 * (*pk++)) + gcurr1;
345 <a name="l00379"></a>00379
346 <a name="l00380"></a>00380 <span class="comment">/* save g1(n) in state buffer */</span>
347 <a name="l00381"></a>00381 *px++ = fcurr1;
348 <a name="l00382"></a>00382
349 <a name="l00383"></a>00383 <span class="comment">/* f1(n) is saved in fcurr1 </span>
350 <a name="l00384"></a>00384 <span class="comment"> for next stage processing */</span>
351 <a name="l00385"></a>00385 fcurr1 = fnext1;
352 <a name="l00386"></a>00386
353 <a name="l00387"></a>00387 stageCnt = (numStages - 1u);
354 <a name="l00388"></a>00388
355 <a name="l00389"></a>00389 <span class="comment">/* stage loop */</span>
356 <a name="l00390"></a>00390 <span class="keywordflow">while</span>(stageCnt > 0u)
357 <a name="l00391"></a>00391 {
358 <a name="l00392"></a>00392 <span class="comment">/* read g2(n) from state buffer */</span>
359 <a name="l00393"></a>00393 gcurr1 = *px;
360 <a name="l00394"></a>00394
361 <a name="l00395"></a>00395 <span class="comment">/* save g1(n) in state buffer */</span>
362 <a name="l00396"></a>00396 *px++ = gnext1;
363 <a name="l00397"></a>00397
364 <a name="l00398"></a>00398 <span class="comment">/* Sample processing for K2, K3.... */</span>
365 <a name="l00399"></a>00399 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
366 <a name="l00400"></a>00400 fnext1 = fcurr1 + ((*pk) * gcurr1);
367 <a name="l00401"></a>00401 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
368 <a name="l00402"></a>00402 gnext1 = (fcurr1 * (*pk++)) + gcurr1;
369 <a name="l00403"></a>00403
370 <a name="l00404"></a>00404 <span class="comment">/* f1(n) is saved in fcurr1 </span>
371 <a name="l00405"></a>00405 <span class="comment"> for next stage processing */</span>
372 <a name="l00406"></a>00406 fcurr1 = fnext1;
373 <a name="l00407"></a>00407
374 <a name="l00408"></a>00408 stageCnt--;
375 <a name="l00409"></a>00409
376 <a name="l00410"></a>00410 }
377 <a name="l00411"></a>00411
378 <a name="l00412"></a>00412 <span class="comment">/* y(n) = fN(n) */</span>
379 <a name="l00413"></a>00413 *pDst++ = fcurr1;
380 <a name="l00414"></a>00414
381 <a name="l00415"></a>00415 blkCnt--;
382 <a name="l00416"></a>00416
383 <a name="l00417"></a>00417 }
384 <a name="l00418"></a>00418
385 <a name="l00419"></a>00419 <span class="preprocessor">#else</span>
386 <a name="l00420"></a>00420 <span class="preprocessor"></span>
387 <a name="l00421"></a>00421 <span class="comment">/* Run the below code for Cortex-M0 */</span>
388 <a name="l00422"></a>00422
389 <a name="l00423"></a>00423 <a class="code" href="arm__math_8h.html#a4611b605e45ab401f02cab15c5e38715" title="32-bit floating-point type definition.">float32_t</a> fcurr, fnext, gcurr, gnext; <span class="comment">/* temporary variables */</span>
390 <a name="l00424"></a>00424 uint32_t numStages = S-><a class="code" href="structarm__fir__lattice__instance__f32.html#ad369bd9997a250f195254df37408a38f">numStages</a>; <span class="comment">/* Length of the filter */</span>
391 <a name="l00425"></a>00425 uint32_t blkCnt, stageCnt; <span class="comment">/* temporary variables for counts */</span>
392 <a name="l00426"></a>00426
393 <a name="l00427"></a>00427 pState = &S-><a class="code" href="structarm__fir__lattice__instance__f32.html#ae348884a1ba9b83fadccd5da640cbcaf">pState</a>[0];
394 <a name="l00428"></a>00428
395 <a name="l00429"></a>00429 blkCnt = <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>;
396 <a name="l00430"></a>00430
397 <a name="l00431"></a>00431 <span class="keywordflow">while</span>(blkCnt > 0u)
398 <a name="l00432"></a>00432 {
399 <a name="l00433"></a>00433 <span class="comment">/* f0(n) = x(n) */</span>
400 <a name="l00434"></a>00434 fcurr = *pSrc++;
401 <a name="l00435"></a>00435
402 <a name="l00436"></a>00436 <span class="comment">/* Initialize coeff pointer */</span>
403 <a name="l00437"></a>00437 pk = pCoeffs;
404 <a name="l00438"></a>00438
405 <a name="l00439"></a>00439 <span class="comment">/* Initialize state pointer */</span>
406 <a name="l00440"></a>00440 px = pState;
407 <a name="l00441"></a>00441
408 <a name="l00442"></a>00442 <span class="comment">/* read g0(n-1) from state buffer */</span>
409 <a name="l00443"></a>00443 gcurr = *px;
410 <a name="l00444"></a>00444
411 <a name="l00445"></a>00445 <span class="comment">/* for sample 1 processing */</span>
412 <a name="l00446"></a>00446 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
413 <a name="l00447"></a>00447 fnext = fcurr + ((*pk) * gcurr);
414 <a name="l00448"></a>00448 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
415 <a name="l00449"></a>00449 gnext = (fcurr * (*pk++)) + gcurr;
416 <a name="l00450"></a>00450
417 <a name="l00451"></a>00451 <span class="comment">/* save f0(n) in state buffer */</span>
418 <a name="l00452"></a>00452 *px++ = fcurr;
419 <a name="l00453"></a>00453
420 <a name="l00454"></a>00454 <span class="comment">/* f1(n) is saved in fcurr </span>
421 <a name="l00455"></a>00455 <span class="comment"> for next stage processing */</span>
422 <a name="l00456"></a>00456 fcurr = fnext;
423 <a name="l00457"></a>00457
424 <a name="l00458"></a>00458 stageCnt = (numStages - 1u);
425 <a name="l00459"></a>00459
426 <a name="l00460"></a>00460 <span class="comment">/* stage loop */</span>
427 <a name="l00461"></a>00461 <span class="keywordflow">while</span>(stageCnt > 0u)
428 <a name="l00462"></a>00462 {
429 <a name="l00463"></a>00463 <span class="comment">/* read g2(n) from state buffer */</span>
430 <a name="l00464"></a>00464 gcurr = *px;
431 <a name="l00465"></a>00465
432 <a name="l00466"></a>00466 <span class="comment">/* save g1(n) in state buffer */</span>
433 <a name="l00467"></a>00467 *px++ = gnext;
434 <a name="l00468"></a>00468
435 <a name="l00469"></a>00469 <span class="comment">/* Sample processing for K2, K3.... */</span>
436 <a name="l00470"></a>00470 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
437 <a name="l00471"></a>00471 fnext = fcurr + ((*pk) * gcurr);
438 <a name="l00472"></a>00472 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
439 <a name="l00473"></a>00473 gnext = (fcurr * (*pk++)) + gcurr;
440 <a name="l00474"></a>00474
441 <a name="l00475"></a>00475 <span class="comment">/* f1(n) is saved in fcurr1 </span>
442 <a name="l00476"></a>00476 <span class="comment"> for next stage processing */</span>
443 <a name="l00477"></a>00477 fcurr = fnext;
444 <a name="l00478"></a>00478
445 <a name="l00479"></a>00479 stageCnt--;
446 <a name="l00480"></a>00480
447 <a name="l00481"></a>00481 }
448 <a name="l00482"></a>00482
449 <a name="l00483"></a>00483 <span class="comment">/* y(n) = fN(n) */</span>
450 <a name="l00484"></a>00484 *pDst++ = fcurr;
451 <a name="l00485"></a>00485
452 <a name="l00486"></a>00486 blkCnt--;
453 <a name="l00487"></a>00487
454 <a name="l00488"></a>00488 }
455 <a name="l00489"></a>00489
456 <a name="l00490"></a>00490 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span>
457 <a name="l00491"></a>00491
458 <a name="l00492"></a>00492 }
459 <a name="l00493"></a>00493
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464 onmouseover="return searchBox.OnSearchSelectShow()"
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