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49 <div class="headertitle">
50 <h1>arm_fir_lattice_q31.c</h1> </div>
52 <div class="contents">
53 <a href="arm__fir__lattice__q31_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_q31.c </span>
61 <a name="l00009"></a>00009 <span class="comment">* </span>
62 <a name="l00010"></a>00010 <span class="comment">* Description: Q31 FIR lattice filter processing function. </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="l00058"></a><a class="code" href="group___f_i_r___lattice.html#ga2e36fd210e4a1a5dd333ce80dd6d9a88">00058</a> <span class="keywordtype">void</span> <a class="code" href="group___f_i_r___lattice.html#ga2e36fd210e4a1a5dd333ce80dd6d9a88" title="Processing function for the Q31 FIR lattice filter.">arm_fir_lattice_q31</a>(
88 <a name="l00059"></a>00059 <span class="keyword">const</span> <a class="code" href="structarm__fir__lattice__instance__q31.html" title="Instance structure for the Q31 FIR lattice filter.">arm_fir_lattice_instance_q31</a> * S,
89 <a name="l00060"></a>00060 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pSrc,
90 <a name="l00061"></a>00061 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> * pDst,
91 <a name="l00062"></a>00062 uint32_t <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>)
92 <a name="l00063"></a>00063 {
93 <a name="l00064"></a>00064 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pState; <span class="comment">/* State pointer */</span>
94 <a name="l00065"></a>00065 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pCoeffs = S-><a class="code" href="structarm__fir__lattice__instance__q31.html#a66c3364bf5863cd45e05f1652c3dc522">pCoeffs</a>; <span class="comment">/* Coefficient pointer */</span>
95 <a name="l00066"></a>00066 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *px; <span class="comment">/* temporary state pointer */</span>
96 <a name="l00067"></a>00067 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> *pk; <span class="comment">/* temporary coefficient pointer */</span>
97 <a name="l00068"></a>00068
98 <a name="l00069"></a>00069
99 <a name="l00070"></a>00070 <span class="preprocessor">#ifndef ARM_MATH_CM0</span>
100 <a name="l00071"></a>00071 <span class="preprocessor"></span>
101 <a name="l00072"></a>00072 <span class="comment">/* Run the below code for Cortex-M4 and Cortex-M3 */</span>
102 <a name="l00073"></a>00073
103 <a name="l00074"></a>00074 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> fcurr1, fnext1, gcurr1 = 0, gnext1; <span class="comment">/* temporary variables for first sample in loop unrolling */</span>
104 <a name="l00075"></a>00075 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> fcurr2, fnext2, gnext2; <span class="comment">/* temporary variables for second sample in loop unrolling */</span>
105 <a name="l00076"></a>00076 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> fcurr3, fnext3, gnext3; <span class="comment">/* temporary variables for third sample in loop unrolling */</span>
106 <a name="l00077"></a>00077 <a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a> fcurr4, fnext4, gnext4; <span class="comment">/* temporary variables for fourth sample in loop unrolling */</span>
107 <a name="l00078"></a>00078 uint32_t numStages = S-><a class="code" href="structarm__fir__lattice__instance__q31.html#a9f3773bbb76bc5a8a5ee9d37786bf478">numStages</a>; <span class="comment">/* Length of the filter */</span>
108 <a name="l00079"></a>00079 uint32_t blkCnt, stageCnt; <span class="comment">/* temporary variables for counts */</span>
109 <a name="l00080"></a>00080
110 <a name="l00081"></a>00081 pState = &S-><a class="code" href="structarm__fir__lattice__instance__q31.html#a08fe9494ab7cd336b791e9657adadcf6">pState</a>[0];
111 <a name="l00082"></a>00082
112 <a name="l00083"></a>00083 blkCnt = blockSize >> 2u;
113 <a name="l00084"></a>00084
114 <a name="l00085"></a>00085 <span class="comment">/* First part of the processing with loop unrolling. Compute 4 outputs at a time. </span>
115 <a name="l00086"></a>00086 <span class="comment"> ** a second loop below computes the remaining 1 to 3 samples. */</span>
116 <a name="l00087"></a>00087 <span class="keywordflow">while</span>(blkCnt > 0u)
117 <a name="l00088"></a>00088 {
118 <a name="l00089"></a>00089
119 <a name="l00090"></a>00090 <span class="comment">/* Read two samples from input buffer */</span>
120 <a name="l00091"></a>00091 <span class="comment">/* f0(n) = x(n) */</span>
121 <a name="l00092"></a>00092 fcurr1 = *pSrc++;
122 <a name="l00093"></a>00093 <span class="comment">/* f0(n) = x(n) */</span>
123 <a name="l00094"></a>00094 fcurr2 = *pSrc++;
124 <a name="l00095"></a>00095
125 <a name="l00096"></a>00096 <span class="comment">/* Initialize coeff pointer */</span>
126 <a name="l00097"></a>00097 pk = (pCoeffs);
127 <a name="l00098"></a>00098
128 <a name="l00099"></a>00099 <span class="comment">/* Initialize state pointer */</span>
129 <a name="l00100"></a>00100 px = pState;
130 <a name="l00101"></a>00101
131 <a name="l00102"></a>00102 <span class="comment">/* Read g0(n-1) from state */</span>
132 <a name="l00103"></a>00103 gcurr1 = *px;
133 <a name="l00104"></a>00104
134 <a name="l00105"></a>00105 <span class="comment">/* Process first sample for first tap */</span>
135 <a name="l00106"></a>00106 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
136 <a name="l00107"></a>00107 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
137 <a name="l00108"></a>00108 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
138 <a name="l00109"></a>00109 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk)) >> 31) + gcurr1;
139 <a name="l00110"></a>00110
140 <a name="l00111"></a>00111 <span class="comment">/* Process second sample for first tap */</span>
141 <a name="l00112"></a>00112 <span class="comment">/* for sample 2 processing */</span>
142 <a name="l00113"></a>00113 fnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk)) >> 31) + fcurr2;
143 <a name="l00114"></a>00114 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr2 * (*pk)) >> 31) + fcurr1;
144 <a name="l00115"></a>00115
145 <a name="l00116"></a>00116
146 <a name="l00117"></a>00117 <span class="comment">/* Read next two samples from input buffer */</span>
147 <a name="l00118"></a>00118 <span class="comment">/* f0(n+2) = x(n+2) */</span>
148 <a name="l00119"></a>00119 fcurr3 = *pSrc++;
149 <a name="l00120"></a>00120 fcurr4 = *pSrc++;
150 <a name="l00121"></a>00121
151 <a name="l00122"></a>00122 <span class="comment">/* Copy only last input samples into the state buffer </span>
152 <a name="l00123"></a>00123 <span class="comment"> which will be used for next four samples processing */</span>
153 <a name="l00124"></a>00124 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) fcurr4;
154 <a name="l00125"></a>00125
155 <a name="l00126"></a>00126 <span class="comment">/* Process third sample for first tap */</span>
156 <a name="l00127"></a>00127 fnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr2 * (*pk)) >> 31) + fcurr3;
157 <a name="l00128"></a>00128 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr3 * (*pk)) >> 31) + fcurr2;
158 <a name="l00129"></a>00129
159 <a name="l00130"></a>00130 <span class="comment">/* Process fourth sample for first tap */</span>
160 <a name="l00131"></a>00131 fnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr3 * (*pk)) >> 31) + fcurr4;
161 <a name="l00132"></a>00132 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr4 * (*pk++)) >> 31) + fcurr3;
162 <a name="l00133"></a>00133
163 <a name="l00134"></a>00134 <span class="comment">/* save g1(n) in state buffer for next sample processing */</span>
164 <a name="l00135"></a>00135 <span class="comment">/* *px++ = gnext4; */</span>
165 <a name="l00136"></a>00136
166 <a name="l00137"></a>00137 <span class="comment">/* Update of f values for next coefficient set processing */</span>
167 <a name="l00138"></a>00138 fcurr1 = fnext1;
168 <a name="l00139"></a>00139 fcurr2 = fnext2;
169 <a name="l00140"></a>00140 fcurr3 = fnext3;
170 <a name="l00141"></a>00141 fcurr4 = fnext4;
171 <a name="l00142"></a>00142
172 <a name="l00143"></a>00143
173 <a name="l00144"></a>00144 <span class="comment">/* Loop unrolling. Process 4 taps at a time . */</span>
174 <a name="l00145"></a>00145 stageCnt = (numStages - 1u) >> 2u;
175 <a name="l00146"></a>00146
176 <a name="l00147"></a>00147
177 <a name="l00148"></a>00148 <span class="comment">/* Loop over the number of taps. Unroll by a factor of 4. </span>
178 <a name="l00149"></a>00149 <span class="comment"> ** Repeat until we've computed numStages-3 coefficients. */</span>
179 <a name="l00150"></a>00150
180 <a name="l00151"></a>00151 <span class="comment">/* Process 2nd, 3rd, 4th and 5th taps ... here */</span>
181 <a name="l00152"></a>00152 <span class="keywordflow">while</span>(stageCnt > 0u)
182 <a name="l00153"></a>00153 {
183 <a name="l00154"></a>00154 <span class="comment">/* Read g1(n-1), g3(n-1) .... from state */</span>
184 <a name="l00155"></a>00155 gcurr1 = *px;
185 <a name="l00156"></a>00156
186 <a name="l00157"></a>00157 <span class="comment">/* save g1(n) in state buffer */</span>
187 <a name="l00158"></a>00158 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) gnext4;
188 <a name="l00159"></a>00159
189 <a name="l00160"></a>00160 <span class="comment">/* Process first sample for 2nd, 6th .. tap */</span>
190 <a name="l00161"></a>00161 <span class="comment">/* Sample processing for K2, K6.... */</span>
191 <a name="l00162"></a>00162 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
192 <a name="l00163"></a>00163 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
193 <a name="l00164"></a>00164 <span class="comment">/* Process second sample for 2nd, 6th .. tap */</span>
194 <a name="l00165"></a>00165 <span class="comment">/* for sample 2 processing */</span>
195 <a name="l00166"></a>00166 fnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext1 * (*pk)) >> 31) + fcurr2;
196 <a name="l00167"></a>00167 <span class="comment">/* Process third sample for 2nd, 6th .. tap */</span>
197 <a name="l00168"></a>00168 fnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext2 * (*pk)) >> 31) + fcurr3;
198 <a name="l00169"></a>00169 <span class="comment">/* Process fourth sample for 2nd, 6th .. tap */</span>
199 <a name="l00170"></a>00170 fnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext3 * (*pk)) >> 31) + fcurr4;
200 <a name="l00171"></a>00171
201 <a name="l00172"></a>00172 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
202 <a name="l00173"></a>00173 <span class="comment">/* Calculation of state values for next stage */</span>
203 <a name="l00174"></a>00174 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr4 * (*pk)) >> 31) + gnext3;
204 <a name="l00175"></a>00175 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr3 * (*pk)) >> 31) + gnext2;
205 <a name="l00176"></a>00176 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr2 * (*pk)) >> 31) + gnext1;
206 <a name="l00177"></a>00177 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk++)) >> 31) + gcurr1;
207 <a name="l00178"></a>00178
208 <a name="l00179"></a>00179
209 <a name="l00180"></a>00180 <span class="comment">/* Read g2(n-1), g4(n-1) .... from state */</span>
210 <a name="l00181"></a>00181 gcurr1 = *px;
211 <a name="l00182"></a>00182
212 <a name="l00183"></a>00183 <span class="comment">/* save g2(n) in state buffer */</span>
213 <a name="l00184"></a>00184 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) gnext4;
214 <a name="l00185"></a>00185
215 <a name="l00186"></a>00186 <span class="comment">/* Sample processing for K3, K7.... */</span>
216 <a name="l00187"></a>00187 <span class="comment">/* Process first sample for 3rd, 7th .. tap */</span>
217 <a name="l00188"></a>00188 <span class="comment">/* f3(n) = f2(n) + K3 * g2(n-1) */</span>
218 <a name="l00189"></a>00189 fcurr1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fnext1;
219 <a name="l00190"></a>00190 <span class="comment">/* Process second sample for 3rd, 7th .. tap */</span>
220 <a name="l00191"></a>00191 fcurr2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext1 * (*pk)) >> 31) + fnext2;
221 <a name="l00192"></a>00192 <span class="comment">/* Process third sample for 3rd, 7th .. tap */</span>
222 <a name="l00193"></a>00193 fcurr3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext2 * (*pk)) >> 31) + fnext3;
223 <a name="l00194"></a>00194 <span class="comment">/* Process fourth sample for 3rd, 7th .. tap */</span>
224 <a name="l00195"></a>00195 fcurr4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext3 * (*pk)) >> 31) + fnext4;
225 <a name="l00196"></a>00196
226 <a name="l00197"></a>00197 <span class="comment">/* Calculation of state values for next stage */</span>
227 <a name="l00198"></a>00198 <span class="comment">/* gnext4 = fnext4 * (*pk) + gnext3; */</span>
228 <a name="l00199"></a>00199 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext4 * (*pk)) >> 31) + gnext3;
229 <a name="l00200"></a>00200 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext3 * (*pk)) >> 31) + gnext2;
230 <a name="l00201"></a>00201 <span class="comment">/* gnext2 = fnext2 * (*pk) + gnext1; */</span>
231 <a name="l00202"></a>00202 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext2 * (*pk)) >> 31) + gnext1;
232 <a name="l00203"></a>00203
233 <a name="l00204"></a>00204 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
234 <a name="l00205"></a>00205 <span class="comment">/* gnext1 = fnext1 * (*pk++) + gcurr1; */</span>
235 <a name="l00206"></a>00206 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext1 * (*pk++)) >> 31) + gcurr1;
236 <a name="l00207"></a>00207
237 <a name="l00208"></a>00208 <span class="comment">/* Read g1(n-1), g3(n-1) .... from state */</span>
238 <a name="l00209"></a>00209 gcurr1 = *px;
239 <a name="l00210"></a>00210
240 <a name="l00211"></a>00211 <span class="comment">/* save g1(n) in state buffer */</span>
241 <a name="l00212"></a>00212 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) gnext4;
242 <a name="l00213"></a>00213
243 <a name="l00214"></a>00214 <span class="comment">/* Sample processing for K4, K8.... */</span>
244 <a name="l00215"></a>00215 <span class="comment">/* Process first sample for 4th, 8th .. tap */</span>
245 <a name="l00216"></a>00216 <span class="comment">/* f4(n) = f3(n) + K4 * g3(n-1) */</span>
246 <a name="l00217"></a>00217 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
247 <a name="l00218"></a>00218 <span class="comment">/* Process second sample for 4th, 8th .. tap */</span>
248 <a name="l00219"></a>00219 <span class="comment">/* for sample 2 processing */</span>
249 <a name="l00220"></a>00220 fnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext1 * (*pk)) >> 31) + fcurr2;
250 <a name="l00221"></a>00221 <span class="comment">/* Process third sample for 4th, 8th .. tap */</span>
251 <a name="l00222"></a>00222 fnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext2 * (*pk)) >> 31) + fcurr3;
252 <a name="l00223"></a>00223 <span class="comment">/* Process fourth sample for 4th, 8th .. tap */</span>
253 <a name="l00224"></a>00224 fnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext3 * (*pk)) >> 31) + fcurr4;
254 <a name="l00225"></a>00225
255 <a name="l00226"></a>00226 <span class="comment">/* g4(n) = f3(n) * K4 + g3(n-1) */</span>
256 <a name="l00227"></a>00227 <span class="comment">/* Calculation of state values for next stage */</span>
257 <a name="l00228"></a>00228 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr4 * (*pk)) >> 31) + gnext3;
258 <a name="l00229"></a>00229 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr3 * (*pk)) >> 31) + gnext2;
259 <a name="l00230"></a>00230 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr2 * (*pk)) >> 31) + gnext1;
260 <a name="l00231"></a>00231 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk++)) >> 31) + gcurr1;
261 <a name="l00232"></a>00232
262 <a name="l00233"></a>00233 <span class="comment">/* Read g2(n-1), g4(n-1) .... from state */</span>
263 <a name="l00234"></a>00234 gcurr1 = *px;
264 <a name="l00235"></a>00235
265 <a name="l00236"></a>00236 <span class="comment">/* save g4(n) in state buffer */</span>
266 <a name="l00237"></a>00237 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) gnext4;
267 <a name="l00238"></a>00238
268 <a name="l00239"></a>00239 <span class="comment">/* Sample processing for K5, K9.... */</span>
269 <a name="l00240"></a>00240 <span class="comment">/* Process first sample for 5th, 9th .. tap */</span>
270 <a name="l00241"></a>00241 <span class="comment">/* f5(n) = f4(n) + K5 * g4(n-1) */</span>
271 <a name="l00242"></a>00242 fcurr1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fnext1;
272 <a name="l00243"></a>00243 <span class="comment">/* Process second sample for 5th, 9th .. tap */</span>
273 <a name="l00244"></a>00244 fcurr2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext1 * (*pk)) >> 31) + fnext2;
274 <a name="l00245"></a>00245 <span class="comment">/* Process third sample for 5th, 9th .. tap */</span>
275 <a name="l00246"></a>00246 fcurr3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext2 * (*pk)) >> 31) + fnext3;
276 <a name="l00247"></a>00247 <span class="comment">/* Process fourth sample for 5th, 9th .. tap */</span>
277 <a name="l00248"></a>00248 fcurr4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext3 * (*pk)) >> 31) + fnext4;
278 <a name="l00249"></a>00249
279 <a name="l00250"></a>00250 <span class="comment">/* Calculation of state values for next stage */</span>
280 <a name="l00251"></a>00251 <span class="comment">/* g5(n) = f4(n) * K5 + g4(n-1) */</span>
281 <a name="l00252"></a>00252 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext4 * (*pk)) >> 31) + gnext3;
282 <a name="l00253"></a>00253 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext3 * (*pk)) >> 31) + gnext2;
283 <a name="l00254"></a>00254 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext2 * (*pk)) >> 31) + gnext1;
284 <a name="l00255"></a>00255 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fnext1 * (*pk++)) >> 31) + gcurr1;
285 <a name="l00256"></a>00256
286 <a name="l00257"></a>00257 stageCnt--;
287 <a name="l00258"></a>00258 }
288 <a name="l00259"></a>00259
289 <a name="l00260"></a>00260 <span class="comment">/* If the (filter length -1) is not a multiple of 4, compute the remaining filter taps */</span>
290 <a name="l00261"></a>00261 stageCnt = (numStages - 1u) % 0x4u;
291 <a name="l00262"></a>00262
292 <a name="l00263"></a>00263 <span class="keywordflow">while</span>(stageCnt > 0u)
293 <a name="l00264"></a>00264 {
294 <a name="l00265"></a>00265 gcurr1 = *px;
295 <a name="l00266"></a>00266
296 <a name="l00267"></a>00267 <span class="comment">/* save g value in state buffer */</span>
297 <a name="l00268"></a>00268 *px++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) gnext4;
298 <a name="l00269"></a>00269
299 <a name="l00270"></a>00270 <span class="comment">/* Process four samples for last three taps here */</span>
300 <a name="l00271"></a>00271 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
301 <a name="l00272"></a>00272 fnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext1 * (*pk)) >> 31) + fcurr2;
302 <a name="l00273"></a>00273 fnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext2 * (*pk)) >> 31) + fcurr3;
303 <a name="l00274"></a>00274 fnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gnext3 * (*pk)) >> 31) + fcurr4;
304 <a name="l00275"></a>00275
305 <a name="l00276"></a>00276 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
306 <a name="l00277"></a>00277 gnext4 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr4 * (*pk)) >> 31) + gnext3;
307 <a name="l00278"></a>00278 gnext3 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr3 * (*pk)) >> 31) + gnext2;
308 <a name="l00279"></a>00279 gnext2 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr2 * (*pk)) >> 31) + gnext1;
309 <a name="l00280"></a>00280 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk++)) >> 31) + gcurr1;
310 <a name="l00281"></a>00281
311 <a name="l00282"></a>00282 <span class="comment">/* Update of f values for next coefficient set processing */</span>
312 <a name="l00283"></a>00283 fcurr1 = fnext1;
313 <a name="l00284"></a>00284 fcurr2 = fnext2;
314 <a name="l00285"></a>00285 fcurr3 = fnext3;
315 <a name="l00286"></a>00286 fcurr4 = fnext4;
316 <a name="l00287"></a>00287
317 <a name="l00288"></a>00288 stageCnt--;
318 <a name="l00289"></a>00289
319 <a name="l00290"></a>00290 }
320 <a name="l00291"></a>00291
321 <a name="l00292"></a>00292 <span class="comment">/* The results in the 4 accumulators, store in the destination buffer. */</span>
322 <a name="l00293"></a>00293 <span class="comment">/* y(n) = fN(n) */</span>
323 <a name="l00294"></a>00294 *pDst++ = fcurr1;
324 <a name="l00295"></a>00295 *pDst++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) fcurr2;
325 <a name="l00296"></a>00296 *pDst++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) fcurr3;
326 <a name="l00297"></a>00297 *pDst++ = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) fcurr4;
327 <a name="l00298"></a>00298
328 <a name="l00299"></a>00299 blkCnt--;
329 <a name="l00300"></a>00300 }
330 <a name="l00301"></a>00301
331 <a name="l00302"></a>00302 <span class="comment">/* If the blockSize is not a multiple of 4, compute any remaining output samples here. </span>
332 <a name="l00303"></a>00303 <span class="comment"> ** No loop unrolling is used. */</span>
333 <a name="l00304"></a>00304 blkCnt = blockSize % 0x4u;
334 <a name="l00305"></a>00305
335 <a name="l00306"></a>00306 <span class="keywordflow">while</span>(blkCnt > 0u)
336 <a name="l00307"></a>00307 {
337 <a name="l00308"></a>00308 <span class="comment">/* f0(n) = x(n) */</span>
338 <a name="l00309"></a>00309 fcurr1 = *pSrc++;
339 <a name="l00310"></a>00310
340 <a name="l00311"></a>00311 <span class="comment">/* Initialize coeff pointer */</span>
341 <a name="l00312"></a>00312 pk = (pCoeffs);
342 <a name="l00313"></a>00313
343 <a name="l00314"></a>00314 <span class="comment">/* Initialize state pointer */</span>
344 <a name="l00315"></a>00315 px = pState;
345 <a name="l00316"></a>00316
346 <a name="l00317"></a>00317 <span class="comment">/* read g2(n) from state buffer */</span>
347 <a name="l00318"></a>00318 gcurr1 = *px;
348 <a name="l00319"></a>00319
349 <a name="l00320"></a>00320 <span class="comment">/* for sample 1 processing */</span>
350 <a name="l00321"></a>00321 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
351 <a name="l00322"></a>00322 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
352 <a name="l00323"></a>00323 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
353 <a name="l00324"></a>00324 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk++)) >> 31) + gcurr1;
354 <a name="l00325"></a>00325 <span class="comment">/* save g1(n) in state buffer */</span>
355 <a name="l00326"></a>00326 *px++ = fcurr1;
356 <a name="l00327"></a>00327
357 <a name="l00328"></a>00328 <span class="comment">/* f1(n) is saved in fcurr1 </span>
358 <a name="l00329"></a>00329 <span class="comment"> for next stage processing */</span>
359 <a name="l00330"></a>00330 fcurr1 = fnext1;
360 <a name="l00331"></a>00331
361 <a name="l00332"></a>00332 stageCnt = (numStages - 1u);
362 <a name="l00333"></a>00333
363 <a name="l00334"></a>00334 <span class="comment">/* stage loop */</span>
364 <a name="l00335"></a>00335 <span class="keywordflow">while</span>(stageCnt > 0u)
365 <a name="l00336"></a>00336 {
366 <a name="l00337"></a>00337 <span class="comment">/* read g2(n) from state buffer */</span>
367 <a name="l00338"></a>00338 gcurr1 = *px;
368 <a name="l00339"></a>00339
369 <a name="l00340"></a>00340 <span class="comment">/* save g1(n) in state buffer */</span>
370 <a name="l00341"></a>00341 *px++ = gnext1;
371 <a name="l00342"></a>00342
372 <a name="l00343"></a>00343 <span class="comment">/* Sample processing for K2, K3.... */</span>
373 <a name="l00344"></a>00344 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
374 <a name="l00345"></a>00345 fnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr1 * (*pk)) >> 31) + fcurr1;
375 <a name="l00346"></a>00346 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
376 <a name="l00347"></a>00347 gnext1 = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr1 * (*pk++)) >> 31) + gcurr1;
377 <a name="l00348"></a>00348
378 <a name="l00349"></a>00349 <span class="comment">/* f1(n) is saved in fcurr1 </span>
379 <a name="l00350"></a>00350 <span class="comment"> for next stage processing */</span>
380 <a name="l00351"></a>00351 fcurr1 = fnext1;
381 <a name="l00352"></a>00352
382 <a name="l00353"></a>00353 stageCnt--;
383 <a name="l00354"></a>00354
384 <a name="l00355"></a>00355 }
385 <a name="l00356"></a>00356
386 <a name="l00357"></a>00357 <span class="comment">/* y(n) = fN(n) */</span>
387 <a name="l00358"></a>00358 *pDst++ = fcurr1;
388 <a name="l00359"></a>00359
389 <a name="l00360"></a>00360 blkCnt--;
390 <a name="l00361"></a>00361
391 <a name="l00362"></a>00362 }
392 <a name="l00363"></a>00363
393 <a name="l00364"></a>00364 <span class="preprocessor">#else</span>
394 <a name="l00365"></a>00365 <span class="preprocessor"></span>
395 <a name="l00366"></a>00366 <span class="comment">/* Run the below code for Cortex-M0 */</span>
396 <a name="l00367"></a>00367
397 <a name="l00368"></a>00368 <a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a> fcurr, fnext, gcurr, gnext; <span class="comment">/* temporary variables */</span>
398 <a name="l00369"></a>00369 uint32_t numStages = S-><a class="code" href="structarm__fir__lattice__instance__q31.html#a9f3773bbb76bc5a8a5ee9d37786bf478">numStages</a>; <span class="comment">/* Length of the filter */</span>
399 <a name="l00370"></a>00370 uint32_t blkCnt, stageCnt; <span class="comment">/* temporary variables for counts */</span>
400 <a name="l00371"></a>00371
401 <a name="l00372"></a>00372 pState = &S-><a class="code" href="structarm__fir__lattice__instance__q31.html#a08fe9494ab7cd336b791e9657adadcf6">pState</a>[0];
402 <a name="l00373"></a>00373
403 <a name="l00374"></a>00374 blkCnt = <a class="code" href="arm__fir__example__f32_8c.html#ab6558f40a619c2502fbc24c880fd4fb0">blockSize</a>;
404 <a name="l00375"></a>00375
405 <a name="l00376"></a>00376 <span class="keywordflow">while</span>(blkCnt > 0u)
406 <a name="l00377"></a>00377 {
407 <a name="l00378"></a>00378 <span class="comment">/* f0(n) = x(n) */</span>
408 <a name="l00379"></a>00379 fcurr = *pSrc++;
409 <a name="l00380"></a>00380
410 <a name="l00381"></a>00381 <span class="comment">/* Initialize coeff pointer */</span>
411 <a name="l00382"></a>00382 pk = (pCoeffs);
412 <a name="l00383"></a>00383
413 <a name="l00384"></a>00384 <span class="comment">/* Initialize state pointer */</span>
414 <a name="l00385"></a>00385 px = pState;
415 <a name="l00386"></a>00386
416 <a name="l00387"></a>00387 <span class="comment">/* read g0(n-1) from state buffer */</span>
417 <a name="l00388"></a>00388 gcurr = *px;
418 <a name="l00389"></a>00389
419 <a name="l00390"></a>00390 <span class="comment">/* for sample 1 processing */</span>
420 <a name="l00391"></a>00391 <span class="comment">/* f1(n) = f0(n) + K1 * g0(n-1) */</span>
421 <a name="l00392"></a>00392 fnext = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr * (*pk)) >> 31) + fcurr;
422 <a name="l00393"></a>00393 <span class="comment">/* g1(n) = f0(n) * K1 + g0(n-1) */</span>
423 <a name="l00394"></a>00394 gnext = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr * (*pk++)) >> 31) + gcurr;
424 <a name="l00395"></a>00395 <span class="comment">/* save g1(n) in state buffer */</span>
425 <a name="l00396"></a>00396 *px++ = fcurr;
426 <a name="l00397"></a>00397
427 <a name="l00398"></a>00398 <span class="comment">/* f1(n) is saved in fcurr1 </span>
428 <a name="l00399"></a>00399 <span class="comment"> for next stage processing */</span>
429 <a name="l00400"></a>00400 fcurr = fnext;
430 <a name="l00401"></a>00401
431 <a name="l00402"></a>00402 stageCnt = (numStages - 1u);
432 <a name="l00403"></a>00403
433 <a name="l00404"></a>00404 <span class="comment">/* stage loop */</span>
434 <a name="l00405"></a>00405 <span class="keywordflow">while</span>(stageCnt > 0u)
435 <a name="l00406"></a>00406 {
436 <a name="l00407"></a>00407 <span class="comment">/* read g2(n) from state buffer */</span>
437 <a name="l00408"></a>00408 gcurr = *px;
438 <a name="l00409"></a>00409
439 <a name="l00410"></a>00410 <span class="comment">/* save g1(n) in state buffer */</span>
440 <a name="l00411"></a>00411 *px++ = gnext;
441 <a name="l00412"></a>00412
442 <a name="l00413"></a>00413 <span class="comment">/* Sample processing for K2, K3.... */</span>
443 <a name="l00414"></a>00414 <span class="comment">/* f2(n) = f1(n) + K2 * g1(n-1) */</span>
444 <a name="l00415"></a>00415 fnext = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) gcurr * (*pk)) >> 31) + fcurr;
445 <a name="l00416"></a>00416 <span class="comment">/* g2(n) = f1(n) * K2 + g1(n-1) */</span>
446 <a name="l00417"></a>00417 gnext = (<a class="code" href="arm__math_8h.html#adc89a3547f5324b7b3b95adec3806bc0" title="32-bit fractional data type in 1.31 format.">q31_t</a>) (((<a class="code" href="arm__math_8h.html#a5aea1cb12fc02d9d44c8abf217eaa5c6" title="64-bit fractional data type in 1.63 format.">q63_t</a>) fcurr * (*pk++)) >> 31) + gcurr;
447 <a name="l00418"></a>00418
448 <a name="l00419"></a>00419 <span class="comment">/* f1(n) is saved in fcurr1 </span>
449 <a name="l00420"></a>00420 <span class="comment"> for next stage processing */</span>
450 <a name="l00421"></a>00421 fcurr = fnext;
451 <a name="l00422"></a>00422
452 <a name="l00423"></a>00423 stageCnt--;
453 <a name="l00424"></a>00424
454 <a name="l00425"></a>00425 }
455 <a name="l00426"></a>00426
456 <a name="l00427"></a>00427 <span class="comment">/* y(n) = fN(n) */</span>
457 <a name="l00428"></a>00428 *pDst++ = fcurr;
458 <a name="l00429"></a>00429
459 <a name="l00430"></a>00430 blkCnt--;
460 <a name="l00431"></a>00431
461 <a name="l00432"></a>00432 }
462 <a name="l00433"></a>00433
463 <a name="l00434"></a>00434 <span class="preprocessor">#endif </span><span class="comment">/* #ifndef ARM_MATH_CM0 */</span>
464 <a name="l00435"></a>00435
465 <a name="l00436"></a>00436 }
466 <a name="l00437"></a>00437
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