CMSIS DSP library
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Fork of mbed-dsp by
cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c@3:7a284390b0ce, 2013-11-08 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Nov 08 13:45:10 2013 +0000
- Revision:
- 3:7a284390b0ce
- Parent:
- 2:da51fb522205
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
emilmont | 1:fdd22bb7aa52 | 1 | /* ---------------------------------------------------------------------- |
mbed_official | 3:7a284390b0ce | 2 | * Copyright (C) 2010-2013 ARM Limited. All rights reserved. |
emilmont | 1:fdd22bb7aa52 | 3 | * |
mbed_official | 3:7a284390b0ce | 4 | * $Date: 17. January 2013 |
mbed_official | 3:7a284390b0ce | 5 | * $Revision: V1.4.1 |
emilmont | 1:fdd22bb7aa52 | 6 | * |
emilmont | 2:da51fb522205 | 7 | * Project: CMSIS DSP Library |
emilmont | 2:da51fb522205 | 8 | * Title: arm_fir_lattice_q31.c |
emilmont | 1:fdd22bb7aa52 | 9 | * |
emilmont | 2:da51fb522205 | 10 | * Description: Q31 FIR lattice filter processing function. |
emilmont | 1:fdd22bb7aa52 | 11 | * |
emilmont | 1:fdd22bb7aa52 | 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
emilmont | 1:fdd22bb7aa52 | 13 | * |
mbed_official | 3:7a284390b0ce | 14 | * Redistribution and use in source and binary forms, with or without |
mbed_official | 3:7a284390b0ce | 15 | * modification, are permitted provided that the following conditions |
mbed_official | 3:7a284390b0ce | 16 | * are met: |
mbed_official | 3:7a284390b0ce | 17 | * - Redistributions of source code must retain the above copyright |
mbed_official | 3:7a284390b0ce | 18 | * notice, this list of conditions and the following disclaimer. |
mbed_official | 3:7a284390b0ce | 19 | * - Redistributions in binary form must reproduce the above copyright |
mbed_official | 3:7a284390b0ce | 20 | * notice, this list of conditions and the following disclaimer in |
mbed_official | 3:7a284390b0ce | 21 | * the documentation and/or other materials provided with the |
mbed_official | 3:7a284390b0ce | 22 | * distribution. |
mbed_official | 3:7a284390b0ce | 23 | * - Neither the name of ARM LIMITED nor the names of its contributors |
mbed_official | 3:7a284390b0ce | 24 | * may be used to endorse or promote products derived from this |
mbed_official | 3:7a284390b0ce | 25 | * software without specific prior written permission. |
mbed_official | 3:7a284390b0ce | 26 | * |
mbed_official | 3:7a284390b0ce | 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
mbed_official | 3:7a284390b0ce | 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
mbed_official | 3:7a284390b0ce | 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
mbed_official | 3:7a284390b0ce | 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
mbed_official | 3:7a284390b0ce | 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
mbed_official | 3:7a284390b0ce | 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
mbed_official | 3:7a284390b0ce | 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
mbed_official | 3:7a284390b0ce | 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
mbed_official | 3:7a284390b0ce | 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
mbed_official | 3:7a284390b0ce | 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
mbed_official | 3:7a284390b0ce | 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
mbed_official | 3:7a284390b0ce | 38 | * POSSIBILITY OF SUCH DAMAGE. |
emilmont | 1:fdd22bb7aa52 | 39 | * -------------------------------------------------------------------- */ |
emilmont | 1:fdd22bb7aa52 | 40 | |
emilmont | 1:fdd22bb7aa52 | 41 | #include "arm_math.h" |
emilmont | 1:fdd22bb7aa52 | 42 | |
emilmont | 1:fdd22bb7aa52 | 43 | /** |
emilmont | 1:fdd22bb7aa52 | 44 | * @ingroup groupFilters |
emilmont | 1:fdd22bb7aa52 | 45 | */ |
emilmont | 1:fdd22bb7aa52 | 46 | |
emilmont | 1:fdd22bb7aa52 | 47 | /** |
emilmont | 1:fdd22bb7aa52 | 48 | * @addtogroup FIR_Lattice |
emilmont | 1:fdd22bb7aa52 | 49 | * @{ |
emilmont | 1:fdd22bb7aa52 | 50 | */ |
emilmont | 1:fdd22bb7aa52 | 51 | |
emilmont | 1:fdd22bb7aa52 | 52 | |
emilmont | 1:fdd22bb7aa52 | 53 | /** |
emilmont | 1:fdd22bb7aa52 | 54 | * @brief Processing function for the Q31 FIR lattice filter. |
emilmont | 1:fdd22bb7aa52 | 55 | * @param[in] *S points to an instance of the Q31 FIR lattice structure. |
emilmont | 1:fdd22bb7aa52 | 56 | * @param[in] *pSrc points to the block of input data. |
emilmont | 1:fdd22bb7aa52 | 57 | * @param[out] *pDst points to the block of output data |
emilmont | 1:fdd22bb7aa52 | 58 | * @param[in] blockSize number of samples to process. |
emilmont | 1:fdd22bb7aa52 | 59 | * @return none. |
emilmont | 1:fdd22bb7aa52 | 60 | * |
emilmont | 1:fdd22bb7aa52 | 61 | * @details |
emilmont | 1:fdd22bb7aa52 | 62 | * <b>Scaling and Overflow Behavior:</b> |
emilmont | 1:fdd22bb7aa52 | 63 | * In order to avoid overflows the input signal must be scaled down by 2*log2(numStages) bits. |
emilmont | 1:fdd22bb7aa52 | 64 | */ |
emilmont | 1:fdd22bb7aa52 | 65 | |
mbed_official | 3:7a284390b0ce | 66 | #ifndef ARM_MATH_CM0_FAMILY |
emilmont | 1:fdd22bb7aa52 | 67 | |
emilmont | 1:fdd22bb7aa52 | 68 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
emilmont | 1:fdd22bb7aa52 | 69 | |
emilmont | 1:fdd22bb7aa52 | 70 | void arm_fir_lattice_q31( |
emilmont | 1:fdd22bb7aa52 | 71 | const arm_fir_lattice_instance_q31 * S, |
emilmont | 1:fdd22bb7aa52 | 72 | q31_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 73 | q31_t * pDst, |
emilmont | 1:fdd22bb7aa52 | 74 | uint32_t blockSize) |
emilmont | 1:fdd22bb7aa52 | 75 | { |
emilmont | 1:fdd22bb7aa52 | 76 | q31_t *pState; /* State pointer */ |
emilmont | 1:fdd22bb7aa52 | 77 | q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 78 | q31_t *px; /* temporary state pointer */ |
emilmont | 1:fdd22bb7aa52 | 79 | q31_t *pk; /* temporary coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 80 | q31_t fcurr1, fnext1, gcurr1 = 0, gnext1; /* temporary variables for first sample in loop unrolling */ |
emilmont | 1:fdd22bb7aa52 | 81 | q31_t fcurr2, fnext2, gnext2; /* temporary variables for second sample in loop unrolling */ |
emilmont | 1:fdd22bb7aa52 | 82 | uint32_t numStages = S->numStages; /* Length of the filter */ |
emilmont | 1:fdd22bb7aa52 | 83 | uint32_t blkCnt, stageCnt; /* temporary variables for counts */ |
emilmont | 1:fdd22bb7aa52 | 84 | q31_t k; |
emilmont | 1:fdd22bb7aa52 | 85 | |
emilmont | 1:fdd22bb7aa52 | 86 | pState = &S->pState[0]; |
emilmont | 1:fdd22bb7aa52 | 87 | |
emilmont | 1:fdd22bb7aa52 | 88 | blkCnt = blockSize >> 1u; |
emilmont | 1:fdd22bb7aa52 | 89 | |
emilmont | 1:fdd22bb7aa52 | 90 | /* First part of the processing with loop unrolling. Compute 2 outputs at a time. |
emilmont | 1:fdd22bb7aa52 | 91 | a second loop below computes the remaining 1 sample. */ |
emilmont | 1:fdd22bb7aa52 | 92 | while(blkCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 93 | { |
emilmont | 1:fdd22bb7aa52 | 94 | /* f0(n) = x(n) */ |
emilmont | 1:fdd22bb7aa52 | 95 | fcurr1 = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 96 | |
emilmont | 1:fdd22bb7aa52 | 97 | /* f0(n) = x(n) */ |
emilmont | 1:fdd22bb7aa52 | 98 | fcurr2 = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 99 | |
emilmont | 1:fdd22bb7aa52 | 100 | /* Initialize coeff pointer */ |
emilmont | 1:fdd22bb7aa52 | 101 | pk = (pCoeffs); |
emilmont | 1:fdd22bb7aa52 | 102 | |
emilmont | 1:fdd22bb7aa52 | 103 | /* Initialize state pointer */ |
emilmont | 1:fdd22bb7aa52 | 104 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 105 | |
emilmont | 1:fdd22bb7aa52 | 106 | /* read g0(n - 1) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 107 | gcurr1 = *px; |
emilmont | 1:fdd22bb7aa52 | 108 | |
emilmont | 1:fdd22bb7aa52 | 109 | /* Read the reflection coefficient */ |
emilmont | 1:fdd22bb7aa52 | 110 | k = *pk++; |
emilmont | 1:fdd22bb7aa52 | 111 | |
emilmont | 1:fdd22bb7aa52 | 112 | /* for sample 1 processing */ |
emilmont | 1:fdd22bb7aa52 | 113 | /* f1(n) = f0(n) + K1 * g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 114 | fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 115 | |
emilmont | 1:fdd22bb7aa52 | 116 | /* g1(n) = f0(n) * K1 + g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 117 | gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 118 | fnext1 = fcurr1 + (fnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 119 | gnext1 = gcurr1 + (gnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 120 | |
emilmont | 1:fdd22bb7aa52 | 121 | /* for sample 1 processing */ |
emilmont | 1:fdd22bb7aa52 | 122 | /* f1(n) = f0(n) + K1 * g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 123 | fnext2 = (q31_t) (((q63_t) fcurr1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 124 | |
emilmont | 1:fdd22bb7aa52 | 125 | /* g1(n) = f0(n) * K1 + g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 126 | gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 127 | fnext2 = fcurr2 + (fnext2 << 1u); |
emilmont | 1:fdd22bb7aa52 | 128 | gnext2 = fcurr1 + (gnext2 << 1u); |
emilmont | 1:fdd22bb7aa52 | 129 | |
emilmont | 1:fdd22bb7aa52 | 130 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 131 | *px++ = fcurr2; |
emilmont | 1:fdd22bb7aa52 | 132 | |
emilmont | 1:fdd22bb7aa52 | 133 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 134 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 135 | fcurr1 = fnext1; |
emilmont | 1:fdd22bb7aa52 | 136 | fcurr2 = fnext2; |
emilmont | 1:fdd22bb7aa52 | 137 | |
emilmont | 1:fdd22bb7aa52 | 138 | stageCnt = (numStages - 1u); |
emilmont | 1:fdd22bb7aa52 | 139 | |
emilmont | 1:fdd22bb7aa52 | 140 | /* stage loop */ |
emilmont | 1:fdd22bb7aa52 | 141 | while(stageCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 142 | { |
emilmont | 1:fdd22bb7aa52 | 143 | |
emilmont | 1:fdd22bb7aa52 | 144 | /* Read the reflection coefficient */ |
emilmont | 1:fdd22bb7aa52 | 145 | k = *pk++; |
emilmont | 1:fdd22bb7aa52 | 146 | |
emilmont | 1:fdd22bb7aa52 | 147 | /* read g2(n) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 148 | gcurr1 = *px; |
emilmont | 1:fdd22bb7aa52 | 149 | |
emilmont | 1:fdd22bb7aa52 | 150 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 151 | *px++ = gnext2; |
emilmont | 1:fdd22bb7aa52 | 152 | |
emilmont | 1:fdd22bb7aa52 | 153 | /* Sample processing for K2, K3.... */ |
emilmont | 1:fdd22bb7aa52 | 154 | /* f2(n) = f1(n) + K2 * g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 155 | fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 156 | fnext2 = (q31_t) (((q63_t) gnext1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 157 | |
emilmont | 1:fdd22bb7aa52 | 158 | fnext1 = fcurr1 + (fnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 159 | fnext2 = fcurr2 + (fnext2 << 1u); |
emilmont | 1:fdd22bb7aa52 | 160 | |
emilmont | 1:fdd22bb7aa52 | 161 | /* g2(n) = f1(n) * K2 + g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 162 | gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 163 | gnext2 = gnext1 + (gnext2 << 1u); |
emilmont | 1:fdd22bb7aa52 | 164 | |
emilmont | 1:fdd22bb7aa52 | 165 | /* g2(n) = f1(n) * K2 + g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 166 | gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 167 | gnext1 = gcurr1 + (gnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 168 | |
emilmont | 1:fdd22bb7aa52 | 169 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 170 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 171 | fcurr1 = fnext1; |
emilmont | 1:fdd22bb7aa52 | 172 | fcurr2 = fnext2; |
emilmont | 1:fdd22bb7aa52 | 173 | |
emilmont | 1:fdd22bb7aa52 | 174 | stageCnt--; |
emilmont | 1:fdd22bb7aa52 | 175 | |
emilmont | 1:fdd22bb7aa52 | 176 | } |
emilmont | 1:fdd22bb7aa52 | 177 | |
emilmont | 1:fdd22bb7aa52 | 178 | /* y(n) = fN(n) */ |
emilmont | 1:fdd22bb7aa52 | 179 | *pDst++ = fcurr1; |
emilmont | 1:fdd22bb7aa52 | 180 | *pDst++ = fcurr2; |
emilmont | 1:fdd22bb7aa52 | 181 | |
emilmont | 1:fdd22bb7aa52 | 182 | blkCnt--; |
emilmont | 1:fdd22bb7aa52 | 183 | |
emilmont | 1:fdd22bb7aa52 | 184 | } |
emilmont | 1:fdd22bb7aa52 | 185 | |
emilmont | 1:fdd22bb7aa52 | 186 | /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
emilmont | 1:fdd22bb7aa52 | 187 | ** No loop unrolling is used. */ |
emilmont | 1:fdd22bb7aa52 | 188 | blkCnt = blockSize % 0x2u; |
emilmont | 1:fdd22bb7aa52 | 189 | |
emilmont | 1:fdd22bb7aa52 | 190 | while(blkCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 191 | { |
emilmont | 1:fdd22bb7aa52 | 192 | /* f0(n) = x(n) */ |
emilmont | 1:fdd22bb7aa52 | 193 | fcurr1 = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 194 | |
emilmont | 1:fdd22bb7aa52 | 195 | /* Initialize coeff pointer */ |
emilmont | 1:fdd22bb7aa52 | 196 | pk = (pCoeffs); |
emilmont | 1:fdd22bb7aa52 | 197 | |
emilmont | 1:fdd22bb7aa52 | 198 | /* Initialize state pointer */ |
emilmont | 1:fdd22bb7aa52 | 199 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 200 | |
emilmont | 1:fdd22bb7aa52 | 201 | /* read g0(n - 1) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 202 | gcurr1 = *px; |
emilmont | 1:fdd22bb7aa52 | 203 | |
emilmont | 1:fdd22bb7aa52 | 204 | /* Read the reflection coefficient */ |
emilmont | 1:fdd22bb7aa52 | 205 | k = *pk++; |
emilmont | 1:fdd22bb7aa52 | 206 | |
emilmont | 1:fdd22bb7aa52 | 207 | /* for sample 1 processing */ |
emilmont | 1:fdd22bb7aa52 | 208 | /* f1(n) = f0(n) + K1 * g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 209 | fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 210 | fnext1 = fcurr1 + (fnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 211 | |
emilmont | 1:fdd22bb7aa52 | 212 | /* g1(n) = f0(n) * K1 + g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 213 | gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 214 | gnext1 = gcurr1 + (gnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 215 | |
emilmont | 1:fdd22bb7aa52 | 216 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 217 | *px++ = fcurr1; |
emilmont | 1:fdd22bb7aa52 | 218 | |
emilmont | 1:fdd22bb7aa52 | 219 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 220 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 221 | fcurr1 = fnext1; |
emilmont | 1:fdd22bb7aa52 | 222 | |
emilmont | 1:fdd22bb7aa52 | 223 | stageCnt = (numStages - 1u); |
emilmont | 1:fdd22bb7aa52 | 224 | |
emilmont | 1:fdd22bb7aa52 | 225 | /* stage loop */ |
emilmont | 1:fdd22bb7aa52 | 226 | while(stageCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 227 | { |
emilmont | 1:fdd22bb7aa52 | 228 | /* Read the reflection coefficient */ |
emilmont | 1:fdd22bb7aa52 | 229 | k = *pk++; |
emilmont | 1:fdd22bb7aa52 | 230 | |
emilmont | 1:fdd22bb7aa52 | 231 | /* read g2(n) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 232 | gcurr1 = *px; |
emilmont | 1:fdd22bb7aa52 | 233 | |
emilmont | 1:fdd22bb7aa52 | 234 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 235 | *px++ = gnext1; |
emilmont | 1:fdd22bb7aa52 | 236 | |
emilmont | 1:fdd22bb7aa52 | 237 | /* Sample processing for K2, K3.... */ |
emilmont | 1:fdd22bb7aa52 | 238 | /* f2(n) = f1(n) + K2 * g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 239 | fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); |
emilmont | 1:fdd22bb7aa52 | 240 | fnext1 = fcurr1 + (fnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 241 | |
emilmont | 1:fdd22bb7aa52 | 242 | /* g2(n) = f1(n) * K2 + g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 243 | gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); |
emilmont | 1:fdd22bb7aa52 | 244 | gnext1 = gcurr1 + (gnext1 << 1u); |
emilmont | 1:fdd22bb7aa52 | 245 | |
emilmont | 1:fdd22bb7aa52 | 246 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 247 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 248 | fcurr1 = fnext1; |
emilmont | 1:fdd22bb7aa52 | 249 | |
emilmont | 1:fdd22bb7aa52 | 250 | stageCnt--; |
emilmont | 1:fdd22bb7aa52 | 251 | |
emilmont | 1:fdd22bb7aa52 | 252 | } |
emilmont | 1:fdd22bb7aa52 | 253 | |
emilmont | 1:fdd22bb7aa52 | 254 | |
emilmont | 1:fdd22bb7aa52 | 255 | /* y(n) = fN(n) */ |
emilmont | 1:fdd22bb7aa52 | 256 | *pDst++ = fcurr1; |
emilmont | 1:fdd22bb7aa52 | 257 | |
emilmont | 1:fdd22bb7aa52 | 258 | blkCnt--; |
emilmont | 1:fdd22bb7aa52 | 259 | |
emilmont | 1:fdd22bb7aa52 | 260 | } |
emilmont | 1:fdd22bb7aa52 | 261 | |
emilmont | 1:fdd22bb7aa52 | 262 | |
emilmont | 1:fdd22bb7aa52 | 263 | } |
emilmont | 1:fdd22bb7aa52 | 264 | |
emilmont | 1:fdd22bb7aa52 | 265 | |
emilmont | 1:fdd22bb7aa52 | 266 | #else |
emilmont | 1:fdd22bb7aa52 | 267 | |
emilmont | 1:fdd22bb7aa52 | 268 | /* Run the below code for Cortex-M0 */ |
emilmont | 1:fdd22bb7aa52 | 269 | |
emilmont | 1:fdd22bb7aa52 | 270 | void arm_fir_lattice_q31( |
emilmont | 1:fdd22bb7aa52 | 271 | const arm_fir_lattice_instance_q31 * S, |
emilmont | 1:fdd22bb7aa52 | 272 | q31_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 273 | q31_t * pDst, |
emilmont | 1:fdd22bb7aa52 | 274 | uint32_t blockSize) |
emilmont | 1:fdd22bb7aa52 | 275 | { |
emilmont | 1:fdd22bb7aa52 | 276 | q31_t *pState; /* State pointer */ |
emilmont | 1:fdd22bb7aa52 | 277 | q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 278 | q31_t *px; /* temporary state pointer */ |
emilmont | 1:fdd22bb7aa52 | 279 | q31_t *pk; /* temporary coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 280 | q31_t fcurr, fnext, gcurr, gnext; /* temporary variables */ |
emilmont | 1:fdd22bb7aa52 | 281 | uint32_t numStages = S->numStages; /* Length of the filter */ |
emilmont | 1:fdd22bb7aa52 | 282 | uint32_t blkCnt, stageCnt; /* temporary variables for counts */ |
emilmont | 1:fdd22bb7aa52 | 283 | |
emilmont | 1:fdd22bb7aa52 | 284 | pState = &S->pState[0]; |
emilmont | 1:fdd22bb7aa52 | 285 | |
emilmont | 1:fdd22bb7aa52 | 286 | blkCnt = blockSize; |
emilmont | 1:fdd22bb7aa52 | 287 | |
emilmont | 1:fdd22bb7aa52 | 288 | while(blkCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 289 | { |
emilmont | 1:fdd22bb7aa52 | 290 | /* f0(n) = x(n) */ |
emilmont | 1:fdd22bb7aa52 | 291 | fcurr = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 292 | |
emilmont | 1:fdd22bb7aa52 | 293 | /* Initialize coeff pointer */ |
emilmont | 1:fdd22bb7aa52 | 294 | pk = (pCoeffs); |
emilmont | 1:fdd22bb7aa52 | 295 | |
emilmont | 1:fdd22bb7aa52 | 296 | /* Initialize state pointer */ |
emilmont | 1:fdd22bb7aa52 | 297 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 298 | |
emilmont | 1:fdd22bb7aa52 | 299 | /* read g0(n-1) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 300 | gcurr = *px; |
emilmont | 1:fdd22bb7aa52 | 301 | |
emilmont | 1:fdd22bb7aa52 | 302 | /* for sample 1 processing */ |
emilmont | 1:fdd22bb7aa52 | 303 | /* f1(n) = f0(n) + K1 * g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 304 | fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr; |
emilmont | 1:fdd22bb7aa52 | 305 | /* g1(n) = f0(n) * K1 + g0(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 306 | gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr; |
emilmont | 1:fdd22bb7aa52 | 307 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 308 | *px++ = fcurr; |
emilmont | 1:fdd22bb7aa52 | 309 | |
emilmont | 1:fdd22bb7aa52 | 310 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 311 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 312 | fcurr = fnext; |
emilmont | 1:fdd22bb7aa52 | 313 | |
emilmont | 1:fdd22bb7aa52 | 314 | stageCnt = (numStages - 1u); |
emilmont | 1:fdd22bb7aa52 | 315 | |
emilmont | 1:fdd22bb7aa52 | 316 | /* stage loop */ |
emilmont | 1:fdd22bb7aa52 | 317 | while(stageCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 318 | { |
emilmont | 1:fdd22bb7aa52 | 319 | /* read g2(n) from state buffer */ |
emilmont | 1:fdd22bb7aa52 | 320 | gcurr = *px; |
emilmont | 1:fdd22bb7aa52 | 321 | |
emilmont | 1:fdd22bb7aa52 | 322 | /* save g1(n) in state buffer */ |
emilmont | 1:fdd22bb7aa52 | 323 | *px++ = gnext; |
emilmont | 1:fdd22bb7aa52 | 324 | |
emilmont | 1:fdd22bb7aa52 | 325 | /* Sample processing for K2, K3.... */ |
emilmont | 1:fdd22bb7aa52 | 326 | /* f2(n) = f1(n) + K2 * g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 327 | fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr; |
emilmont | 1:fdd22bb7aa52 | 328 | /* g2(n) = f1(n) * K2 + g1(n-1) */ |
emilmont | 1:fdd22bb7aa52 | 329 | gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr; |
emilmont | 1:fdd22bb7aa52 | 330 | |
emilmont | 1:fdd22bb7aa52 | 331 | /* f1(n) is saved in fcurr1 |
emilmont | 1:fdd22bb7aa52 | 332 | for next stage processing */ |
emilmont | 1:fdd22bb7aa52 | 333 | fcurr = fnext; |
emilmont | 1:fdd22bb7aa52 | 334 | |
emilmont | 1:fdd22bb7aa52 | 335 | stageCnt--; |
emilmont | 1:fdd22bb7aa52 | 336 | |
emilmont | 1:fdd22bb7aa52 | 337 | } |
emilmont | 1:fdd22bb7aa52 | 338 | |
emilmont | 1:fdd22bb7aa52 | 339 | /* y(n) = fN(n) */ |
emilmont | 1:fdd22bb7aa52 | 340 | *pDst++ = fcurr; |
emilmont | 1:fdd22bb7aa52 | 341 | |
emilmont | 1:fdd22bb7aa52 | 342 | blkCnt--; |
emilmont | 1:fdd22bb7aa52 | 343 | |
emilmont | 1:fdd22bb7aa52 | 344 | } |
emilmont | 1:fdd22bb7aa52 | 345 | |
emilmont | 1:fdd22bb7aa52 | 346 | } |
emilmont | 1:fdd22bb7aa52 | 347 | |
mbed_official | 3:7a284390b0ce | 348 | #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
emilmont | 1:fdd22bb7aa52 | 349 | |
emilmont | 1:fdd22bb7aa52 | 350 | |
emilmont | 1:fdd22bb7aa52 | 351 | /** |
emilmont | 1:fdd22bb7aa52 | 352 | * @} end of FIR_Lattice group |
emilmont | 1:fdd22bb7aa52 | 353 | */ |