Eli Hughes / CMSIS_DSP_401

V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.

Dependents:   MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more

FilteringFunctions/arm_fir_sparse_q15.c@0:3d9c67d97d6f, 2014-07-28 (annotated)

Committer:
emh203
Date:
Mon Jul 28 15:03:15 2014 +0000
Revision:
0:3d9c67d97d6f
1st working commit.   Had to remove arm_bitreversal2.s     arm_cfft_f32.c and arm_rfft_fast_f32.c.    The .s will not assemble.      For now I removed these functions so we could at least have a library for the other functions.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emh203 0:3d9c67d97d6f 1 /* ----------------------------------------------------------------------
emh203 0:3d9c67d97d6f 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emh203 0:3d9c67d97d6f 3 *
emh203 0:3d9c67d97d6f 4 * $Date: 12. March 2014
emh203 0:3d9c67d97d6f 5 * $Revision: V1.4.3
emh203 0:3d9c67d97d6f 6 *
emh203 0:3d9c67d97d6f 7 * Project: CMSIS DSP Library
emh203 0:3d9c67d97d6f 8 * Title: arm_fir_sparse_q15.c
emh203 0:3d9c67d97d6f 9 *
emh203 0:3d9c67d97d6f 10 * Description: Q15 sparse FIR filter processing function.
emh203 0:3d9c67d97d6f 11 *
emh203 0:3d9c67d97d6f 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emh203 0:3d9c67d97d6f 13 *
emh203 0:3d9c67d97d6f 14 * Redistribution and use in source and binary forms, with or without
emh203 0:3d9c67d97d6f 15 * modification, are permitted provided that the following conditions
emh203 0:3d9c67d97d6f 16 * are met:
emh203 0:3d9c67d97d6f 17 * - Redistributions of source code must retain the above copyright
emh203 0:3d9c67d97d6f 18 * notice, this list of conditions and the following disclaimer.
emh203 0:3d9c67d97d6f 19 * - Redistributions in binary form must reproduce the above copyright
emh203 0:3d9c67d97d6f 20 * notice, this list of conditions and the following disclaimer in
emh203 0:3d9c67d97d6f 21 * the documentation and/or other materials provided with the
emh203 0:3d9c67d97d6f 22 * distribution.
emh203 0:3d9c67d97d6f 23 * - Neither the name of ARM LIMITED nor the names of its contributors
emh203 0:3d9c67d97d6f 24 * may be used to endorse or promote products derived from this
emh203 0:3d9c67d97d6f 25 * software without specific prior written permission.
emh203 0:3d9c67d97d6f 26 *
emh203 0:3d9c67d97d6f 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
emh203 0:3d9c67d97d6f 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
emh203 0:3d9c67d97d6f 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
emh203 0:3d9c67d97d6f 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
emh203 0:3d9c67d97d6f 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
emh203 0:3d9c67d97d6f 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
emh203 0:3d9c67d97d6f 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
emh203 0:3d9c67d97d6f 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
emh203 0:3d9c67d97d6f 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
emh203 0:3d9c67d97d6f 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
emh203 0:3d9c67d97d6f 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
emh203 0:3d9c67d97d6f 38 * POSSIBILITY OF SUCH DAMAGE.
emh203 0:3d9c67d97d6f 39 * ------------------------------------------------------------------- */
emh203 0:3d9c67d97d6f 40 #include "arm_math.h"
emh203 0:3d9c67d97d6f 41
emh203 0:3d9c67d97d6f 42 /**
emh203 0:3d9c67d97d6f 43 * @addtogroup FIR_Sparse
emh203 0:3d9c67d97d6f 44 * @{
emh203 0:3d9c67d97d6f 45 */
emh203 0:3d9c67d97d6f 46
emh203 0:3d9c67d97d6f 47 /**
emh203 0:3d9c67d97d6f 48 * @brief Processing function for the Q15 sparse FIR filter.
emh203 0:3d9c67d97d6f 49 * @param[in] *S points to an instance of the Q15 sparse FIR structure.
emh203 0:3d9c67d97d6f 50 * @param[in] *pSrc points to the block of input data.
emh203 0:3d9c67d97d6f 51 * @param[out] *pDst points to the block of output data
emh203 0:3d9c67d97d6f 52 * @param[in] *pScratchIn points to a temporary buffer of size blockSize.
emh203 0:3d9c67d97d6f 53 * @param[in] *pScratchOut points to a temporary buffer of size blockSize.
emh203 0:3d9c67d97d6f 54 * @param[in] blockSize number of input samples to process per call.
emh203 0:3d9c67d97d6f 55 * @return none.
emh203 0:3d9c67d97d6f 56 *
emh203 0:3d9c67d97d6f 57 * <b>Scaling and Overflow Behavior:</b>
emh203 0:3d9c67d97d6f 58 * \par
emh203 0:3d9c67d97d6f 59 * The function is implemented using an internal 32-bit accumulator.
emh203 0:3d9c67d97d6f 60 * The 1.15 x 1.15 multiplications yield a 2.30 result and these are added to a 2.30 accumulator.
emh203 0:3d9c67d97d6f 61 * Thus the full precision of the multiplications is maintained but there is only a single guard bit in the accumulator.
emh203 0:3d9c67d97d6f 62 * If the accumulator result overflows it will wrap around rather than saturate.
emh203 0:3d9c67d97d6f 63 * After all multiply-accumulates are performed, the 2.30 accumulator is truncated to 2.15 format and then saturated to 1.15 format.
emh203 0:3d9c67d97d6f 64 * In order to avoid overflows the input signal or coefficients must be scaled down by log2(numTaps) bits.
emh203 0:3d9c67d97d6f 65 */
emh203 0:3d9c67d97d6f 66
emh203 0:3d9c67d97d6f 67
emh203 0:3d9c67d97d6f 68 void arm_fir_sparse_q15(
emh203 0:3d9c67d97d6f 69 arm_fir_sparse_instance_q15 * S,
emh203 0:3d9c67d97d6f 70 q15_t * pSrc,
emh203 0:3d9c67d97d6f 71 q15_t * pDst,
emh203 0:3d9c67d97d6f 72 q15_t * pScratchIn,
emh203 0:3d9c67d97d6f 73 q31_t * pScratchOut,
emh203 0:3d9c67d97d6f 74 uint32_t blockSize)
emh203 0:3d9c67d97d6f 75 {
emh203 0:3d9c67d97d6f 76
emh203 0:3d9c67d97d6f 77 q15_t *pState = S->pState; /* State pointer */
emh203 0:3d9c67d97d6f 78 q15_t *pIn = pSrc; /* Working pointer for input */
emh203 0:3d9c67d97d6f 79 q15_t *pOut = pDst; /* Working pointer for output */
emh203 0:3d9c67d97d6f 80 q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
emh203 0:3d9c67d97d6f 81 q15_t *px; /* Temporary pointers for scratch buffer */
emh203 0:3d9c67d97d6f 82 q15_t *pb = pScratchIn; /* Temporary pointers for scratch buffer */
emh203 0:3d9c67d97d6f 83 q15_t *py = pState; /* Temporary pointers for state buffer */
emh203 0:3d9c67d97d6f 84 int32_t *pTapDelay = S->pTapDelay; /* Pointer to the array containing offset of the non-zero tap values. */
emh203 0:3d9c67d97d6f 85 uint32_t delaySize = S->maxDelay + blockSize; /* state length */
emh203 0:3d9c67d97d6f 86 uint16_t numTaps = S->numTaps; /* Filter order */
emh203 0:3d9c67d97d6f 87 int32_t readIndex; /* Read index of the state buffer */
emh203 0:3d9c67d97d6f 88 uint32_t tapCnt, blkCnt; /* loop counters */
emh203 0:3d9c67d97d6f 89 q15_t coeff = *pCoeffs++; /* Read the first coefficient value */
emh203 0:3d9c67d97d6f 90 q31_t *pScr2 = pScratchOut; /* Working pointer for pScratchOut */
emh203 0:3d9c67d97d6f 91
emh203 0:3d9c67d97d6f 92
emh203 0:3d9c67d97d6f 93 #ifndef ARM_MATH_CM0_FAMILY
emh203 0:3d9c67d97d6f 94
emh203 0:3d9c67d97d6f 95 /* Run the below code for Cortex-M4 and Cortex-M3 */
emh203 0:3d9c67d97d6f 96
emh203 0:3d9c67d97d6f 97 q31_t in1, in2; /* Temporary variables */
emh203 0:3d9c67d97d6f 98
emh203 0:3d9c67d97d6f 99
emh203 0:3d9c67d97d6f 100 /* BlockSize of Input samples are copied into the state buffer */
emh203 0:3d9c67d97d6f 101 /* StateIndex points to the starting position to write in the state buffer */
emh203 0:3d9c67d97d6f 102 arm_circularWrite_q15(py, delaySize, &S->stateIndex, 1, pIn, 1, blockSize);
emh203 0:3d9c67d97d6f 103
emh203 0:3d9c67d97d6f 104 /* Loop over the number of taps. */
emh203 0:3d9c67d97d6f 105 tapCnt = numTaps;
emh203 0:3d9c67d97d6f 106
emh203 0:3d9c67d97d6f 107 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 108 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 109
emh203 0:3d9c67d97d6f 110 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 111 if(readIndex < 0)
emh203 0:3d9c67d97d6f 112 {
emh203 0:3d9c67d97d6f 113 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 114 }
emh203 0:3d9c67d97d6f 115
emh203 0:3d9c67d97d6f 116 /* Working pointer for state buffer is updated */
emh203 0:3d9c67d97d6f 117 py = pState;
emh203 0:3d9c67d97d6f 118
emh203 0:3d9c67d97d6f 119 /* blockSize samples are read from the state buffer */
emh203 0:3d9c67d97d6f 120 arm_circularRead_q15(py, delaySize, &readIndex, 1,
emh203 0:3d9c67d97d6f 121 pb, pb, blockSize, 1, blockSize);
emh203 0:3d9c67d97d6f 122
emh203 0:3d9c67d97d6f 123 /* Working pointer for the scratch buffer of state values */
emh203 0:3d9c67d97d6f 124 px = pb;
emh203 0:3d9c67d97d6f 125
emh203 0:3d9c67d97d6f 126 /* Working pointer for scratch buffer of output values */
emh203 0:3d9c67d97d6f 127 pScratchOut = pScr2;
emh203 0:3d9c67d97d6f 128
emh203 0:3d9c67d97d6f 129 /* Loop over the blockSize. Unroll by a factor of 4.
emh203 0:3d9c67d97d6f 130 * Compute 4 multiplications at a time. */
emh203 0:3d9c67d97d6f 131 blkCnt = blockSize >> 2;
emh203 0:3d9c67d97d6f 132
emh203 0:3d9c67d97d6f 133 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 134 {
emh203 0:3d9c67d97d6f 135 /* Perform multiplication and store in the scratch buffer */
emh203 0:3d9c67d97d6f 136 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 137 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 138 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 139 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 140
emh203 0:3d9c67d97d6f 141 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 142 blkCnt--;
emh203 0:3d9c67d97d6f 143 }
emh203 0:3d9c67d97d6f 144
emh203 0:3d9c67d97d6f 145 /* If the blockSize is not a multiple of 4,
emh203 0:3d9c67d97d6f 146 * compute the remaining samples */
emh203 0:3d9c67d97d6f 147 blkCnt = blockSize % 0x4u;
emh203 0:3d9c67d97d6f 148
emh203 0:3d9c67d97d6f 149 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 150 {
emh203 0:3d9c67d97d6f 151 /* Perform multiplication and store in the scratch buffer */
emh203 0:3d9c67d97d6f 152 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 153
emh203 0:3d9c67d97d6f 154 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 155 blkCnt--;
emh203 0:3d9c67d97d6f 156 }
emh203 0:3d9c67d97d6f 157
emh203 0:3d9c67d97d6f 158 /* Load the coefficient value and
emh203 0:3d9c67d97d6f 159 * increment the coefficient buffer for the next set of state values */
emh203 0:3d9c67d97d6f 160 coeff = *pCoeffs++;
emh203 0:3d9c67d97d6f 161
emh203 0:3d9c67d97d6f 162 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 163 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 164
emh203 0:3d9c67d97d6f 165 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 166 if(readIndex < 0)
emh203 0:3d9c67d97d6f 167 {
emh203 0:3d9c67d97d6f 168 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 169 }
emh203 0:3d9c67d97d6f 170
emh203 0:3d9c67d97d6f 171 /* Loop over the number of taps. */
emh203 0:3d9c67d97d6f 172 tapCnt = (uint32_t) numTaps - 1u;
emh203 0:3d9c67d97d6f 173
emh203 0:3d9c67d97d6f 174 while(tapCnt > 0u)
emh203 0:3d9c67d97d6f 175 {
emh203 0:3d9c67d97d6f 176 /* Working pointer for state buffer is updated */
emh203 0:3d9c67d97d6f 177 py = pState;
emh203 0:3d9c67d97d6f 178
emh203 0:3d9c67d97d6f 179 /* blockSize samples are read from the state buffer */
emh203 0:3d9c67d97d6f 180 arm_circularRead_q15(py, delaySize, &readIndex, 1,
emh203 0:3d9c67d97d6f 181 pb, pb, blockSize, 1, blockSize);
emh203 0:3d9c67d97d6f 182
emh203 0:3d9c67d97d6f 183 /* Working pointer for the scratch buffer of state values */
emh203 0:3d9c67d97d6f 184 px = pb;
emh203 0:3d9c67d97d6f 185
emh203 0:3d9c67d97d6f 186 /* Working pointer for scratch buffer of output values */
emh203 0:3d9c67d97d6f 187 pScratchOut = pScr2;
emh203 0:3d9c67d97d6f 188
emh203 0:3d9c67d97d6f 189 /* Loop over the blockSize. Unroll by a factor of 4.
emh203 0:3d9c67d97d6f 190 * Compute 4 MACS at a time. */
emh203 0:3d9c67d97d6f 191 blkCnt = blockSize >> 2;
emh203 0:3d9c67d97d6f 192
emh203 0:3d9c67d97d6f 193 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 194 {
emh203 0:3d9c67d97d6f 195 /* Perform Multiply-Accumulate */
emh203 0:3d9c67d97d6f 196 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 197 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 198 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 199 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 200
emh203 0:3d9c67d97d6f 201 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 202 blkCnt--;
emh203 0:3d9c67d97d6f 203 }
emh203 0:3d9c67d97d6f 204
emh203 0:3d9c67d97d6f 205 /* If the blockSize is not a multiple of 4,
emh203 0:3d9c67d97d6f 206 * compute the remaining samples */
emh203 0:3d9c67d97d6f 207 blkCnt = blockSize % 0x4u;
emh203 0:3d9c67d97d6f 208
emh203 0:3d9c67d97d6f 209 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 210 {
emh203 0:3d9c67d97d6f 211 /* Perform Multiply-Accumulate */
emh203 0:3d9c67d97d6f 212 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 213
emh203 0:3d9c67d97d6f 214 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 215 blkCnt--;
emh203 0:3d9c67d97d6f 216 }
emh203 0:3d9c67d97d6f 217
emh203 0:3d9c67d97d6f 218 /* Load the coefficient value and
emh203 0:3d9c67d97d6f 219 * increment the coefficient buffer for the next set of state values */
emh203 0:3d9c67d97d6f 220 coeff = *pCoeffs++;
emh203 0:3d9c67d97d6f 221
emh203 0:3d9c67d97d6f 222 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 223 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 224
emh203 0:3d9c67d97d6f 225 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 226 if(readIndex < 0)
emh203 0:3d9c67d97d6f 227 {
emh203 0:3d9c67d97d6f 228 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 229 }
emh203 0:3d9c67d97d6f 230
emh203 0:3d9c67d97d6f 231 /* Decrement the tap loop counter */
emh203 0:3d9c67d97d6f 232 tapCnt--;
emh203 0:3d9c67d97d6f 233 }
emh203 0:3d9c67d97d6f 234
emh203 0:3d9c67d97d6f 235 /* All the output values are in pScratchOut buffer.
emh203 0:3d9c67d97d6f 236 Convert them into 1.15 format, saturate and store in the destination buffer. */
emh203 0:3d9c67d97d6f 237 /* Loop over the blockSize. */
emh203 0:3d9c67d97d6f 238 blkCnt = blockSize >> 2;
emh203 0:3d9c67d97d6f 239
emh203 0:3d9c67d97d6f 240 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 241 {
emh203 0:3d9c67d97d6f 242 in1 = *pScr2++;
emh203 0:3d9c67d97d6f 243 in2 = *pScr2++;
emh203 0:3d9c67d97d6f 244
emh203 0:3d9c67d97d6f 245 #ifndef ARM_MATH_BIG_ENDIAN
emh203 0:3d9c67d97d6f 246
emh203 0:3d9c67d97d6f 247 *__SIMD32(pOut)++ =
emh203 0:3d9c67d97d6f 248 __PKHBT((q15_t) __SSAT(in1 >> 15, 16), (q15_t) __SSAT(in2 >> 15, 16),
emh203 0:3d9c67d97d6f 249 16);
emh203 0:3d9c67d97d6f 250
emh203 0:3d9c67d97d6f 251 #else
emh203 0:3d9c67d97d6f 252 *__SIMD32(pOut)++ =
emh203 0:3d9c67d97d6f 253 __PKHBT((q15_t) __SSAT(in2 >> 15, 16), (q15_t) __SSAT(in1 >> 15, 16),
emh203 0:3d9c67d97d6f 254 16);
emh203 0:3d9c67d97d6f 255
emh203 0:3d9c67d97d6f 256 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emh203 0:3d9c67d97d6f 257
emh203 0:3d9c67d97d6f 258 in1 = *pScr2++;
emh203 0:3d9c67d97d6f 259
emh203 0:3d9c67d97d6f 260 in2 = *pScr2++;
emh203 0:3d9c67d97d6f 261
emh203 0:3d9c67d97d6f 262 #ifndef ARM_MATH_BIG_ENDIAN
emh203 0:3d9c67d97d6f 263
emh203 0:3d9c67d97d6f 264 *__SIMD32(pOut)++ =
emh203 0:3d9c67d97d6f 265 __PKHBT((q15_t) __SSAT(in1 >> 15, 16), (q15_t) __SSAT(in2 >> 15, 16),
emh203 0:3d9c67d97d6f 266 16);
emh203 0:3d9c67d97d6f 267
emh203 0:3d9c67d97d6f 268 #else
emh203 0:3d9c67d97d6f 269
emh203 0:3d9c67d97d6f 270 *__SIMD32(pOut)++ =
emh203 0:3d9c67d97d6f 271 __PKHBT((q15_t) __SSAT(in2 >> 15, 16), (q15_t) __SSAT(in1 >> 15, 16),
emh203 0:3d9c67d97d6f 272 16);
emh203 0:3d9c67d97d6f 273
emh203 0:3d9c67d97d6f 274 #endif /* #ifndef ARM_MATH_BIG_ENDIAN */
emh203 0:3d9c67d97d6f 275
emh203 0:3d9c67d97d6f 276
emh203 0:3d9c67d97d6f 277 blkCnt--;
emh203 0:3d9c67d97d6f 278
emh203 0:3d9c67d97d6f 279 }
emh203 0:3d9c67d97d6f 280
emh203 0:3d9c67d97d6f 281 /* If the blockSize is not a multiple of 4,
emh203 0:3d9c67d97d6f 282 remaining samples are processed in the below loop */
emh203 0:3d9c67d97d6f 283 blkCnt = blockSize % 0x4u;
emh203 0:3d9c67d97d6f 284
emh203 0:3d9c67d97d6f 285 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 286 {
emh203 0:3d9c67d97d6f 287 *pOut++ = (q15_t) __SSAT(*pScr2++ >> 15, 16);
emh203 0:3d9c67d97d6f 288 blkCnt--;
emh203 0:3d9c67d97d6f 289 }
emh203 0:3d9c67d97d6f 290
emh203 0:3d9c67d97d6f 291 #else
emh203 0:3d9c67d97d6f 292
emh203 0:3d9c67d97d6f 293 /* Run the below code for Cortex-M0 */
emh203 0:3d9c67d97d6f 294
emh203 0:3d9c67d97d6f 295 /* BlockSize of Input samples are copied into the state buffer */
emh203 0:3d9c67d97d6f 296 /* StateIndex points to the starting position to write in the state buffer */
emh203 0:3d9c67d97d6f 297 arm_circularWrite_q15(py, delaySize, &S->stateIndex, 1, pIn, 1, blockSize);
emh203 0:3d9c67d97d6f 298
emh203 0:3d9c67d97d6f 299 /* Loop over the number of taps. */
emh203 0:3d9c67d97d6f 300 tapCnt = numTaps;
emh203 0:3d9c67d97d6f 301
emh203 0:3d9c67d97d6f 302 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 303 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 304
emh203 0:3d9c67d97d6f 305 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 306 if(readIndex < 0)
emh203 0:3d9c67d97d6f 307 {
emh203 0:3d9c67d97d6f 308 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 309 }
emh203 0:3d9c67d97d6f 310
emh203 0:3d9c67d97d6f 311 /* Working pointer for state buffer is updated */
emh203 0:3d9c67d97d6f 312 py = pState;
emh203 0:3d9c67d97d6f 313
emh203 0:3d9c67d97d6f 314 /* blockSize samples are read from the state buffer */
emh203 0:3d9c67d97d6f 315 arm_circularRead_q15(py, delaySize, &readIndex, 1,
emh203 0:3d9c67d97d6f 316 pb, pb, blockSize, 1, blockSize);
emh203 0:3d9c67d97d6f 317
emh203 0:3d9c67d97d6f 318 /* Working pointer for the scratch buffer of state values */
emh203 0:3d9c67d97d6f 319 px = pb;
emh203 0:3d9c67d97d6f 320
emh203 0:3d9c67d97d6f 321 /* Working pointer for scratch buffer of output values */
emh203 0:3d9c67d97d6f 322 pScratchOut = pScr2;
emh203 0:3d9c67d97d6f 323
emh203 0:3d9c67d97d6f 324 blkCnt = blockSize;
emh203 0:3d9c67d97d6f 325
emh203 0:3d9c67d97d6f 326 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 327 {
emh203 0:3d9c67d97d6f 328 /* Perform multiplication and store in the scratch buffer */
emh203 0:3d9c67d97d6f 329 *pScratchOut++ = ((q31_t) * px++ * coeff);
emh203 0:3d9c67d97d6f 330
emh203 0:3d9c67d97d6f 331 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 332 blkCnt--;
emh203 0:3d9c67d97d6f 333 }
emh203 0:3d9c67d97d6f 334
emh203 0:3d9c67d97d6f 335 /* Load the coefficient value and
emh203 0:3d9c67d97d6f 336 * increment the coefficient buffer for the next set of state values */
emh203 0:3d9c67d97d6f 337 coeff = *pCoeffs++;
emh203 0:3d9c67d97d6f 338
emh203 0:3d9c67d97d6f 339 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 340 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 341
emh203 0:3d9c67d97d6f 342 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 343 if(readIndex < 0)
emh203 0:3d9c67d97d6f 344 {
emh203 0:3d9c67d97d6f 345 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 346 }
emh203 0:3d9c67d97d6f 347
emh203 0:3d9c67d97d6f 348 /* Loop over the number of taps. */
emh203 0:3d9c67d97d6f 349 tapCnt = (uint32_t) numTaps - 1u;
emh203 0:3d9c67d97d6f 350
emh203 0:3d9c67d97d6f 351 while(tapCnt > 0u)
emh203 0:3d9c67d97d6f 352 {
emh203 0:3d9c67d97d6f 353 /* Working pointer for state buffer is updated */
emh203 0:3d9c67d97d6f 354 py = pState;
emh203 0:3d9c67d97d6f 355
emh203 0:3d9c67d97d6f 356 /* blockSize samples are read from the state buffer */
emh203 0:3d9c67d97d6f 357 arm_circularRead_q15(py, delaySize, &readIndex, 1,
emh203 0:3d9c67d97d6f 358 pb, pb, blockSize, 1, blockSize);
emh203 0:3d9c67d97d6f 359
emh203 0:3d9c67d97d6f 360 /* Working pointer for the scratch buffer of state values */
emh203 0:3d9c67d97d6f 361 px = pb;
emh203 0:3d9c67d97d6f 362
emh203 0:3d9c67d97d6f 363 /* Working pointer for scratch buffer of output values */
emh203 0:3d9c67d97d6f 364 pScratchOut = pScr2;
emh203 0:3d9c67d97d6f 365
emh203 0:3d9c67d97d6f 366 blkCnt = blockSize;
emh203 0:3d9c67d97d6f 367
emh203 0:3d9c67d97d6f 368 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 369 {
emh203 0:3d9c67d97d6f 370 /* Perform Multiply-Accumulate */
emh203 0:3d9c67d97d6f 371 *pScratchOut++ += (q31_t) * px++ * coeff;
emh203 0:3d9c67d97d6f 372
emh203 0:3d9c67d97d6f 373 /* Decrement the loop counter */
emh203 0:3d9c67d97d6f 374 blkCnt--;
emh203 0:3d9c67d97d6f 375 }
emh203 0:3d9c67d97d6f 376
emh203 0:3d9c67d97d6f 377 /* Load the coefficient value and
emh203 0:3d9c67d97d6f 378 * increment the coefficient buffer for the next set of state values */
emh203 0:3d9c67d97d6f 379 coeff = *pCoeffs++;
emh203 0:3d9c67d97d6f 380
emh203 0:3d9c67d97d6f 381 /* Read Index, from where the state buffer should be read, is calculated. */
emh203 0:3d9c67d97d6f 382 readIndex = (S->stateIndex - blockSize) - *pTapDelay++;
emh203 0:3d9c67d97d6f 383
emh203 0:3d9c67d97d6f 384 /* Wraparound of readIndex */
emh203 0:3d9c67d97d6f 385 if(readIndex < 0)
emh203 0:3d9c67d97d6f 386 {
emh203 0:3d9c67d97d6f 387 readIndex += (int32_t) delaySize;
emh203 0:3d9c67d97d6f 388 }
emh203 0:3d9c67d97d6f 389
emh203 0:3d9c67d97d6f 390 /* Decrement the tap loop counter */
emh203 0:3d9c67d97d6f 391 tapCnt--;
emh203 0:3d9c67d97d6f 392 }
emh203 0:3d9c67d97d6f 393
emh203 0:3d9c67d97d6f 394 /* All the output values are in pScratchOut buffer.
emh203 0:3d9c67d97d6f 395 Convert them into 1.15 format, saturate and store in the destination buffer. */
emh203 0:3d9c67d97d6f 396 /* Loop over the blockSize. */
emh203 0:3d9c67d97d6f 397 blkCnt = blockSize;
emh203 0:3d9c67d97d6f 398
emh203 0:3d9c67d97d6f 399 while(blkCnt > 0u)
emh203 0:3d9c67d97d6f 400 {
emh203 0:3d9c67d97d6f 401 *pOut++ = (q15_t) __SSAT(*pScr2++ >> 15, 16);
emh203 0:3d9c67d97d6f 402 blkCnt--;
emh203 0:3d9c67d97d6f 403 }
emh203 0:3d9c67d97d6f 404
emh203 0:3d9c67d97d6f 405 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emh203 0:3d9c67d97d6f 406
emh203 0:3d9c67d97d6f 407 }
emh203 0:3d9c67d97d6f 408
emh203 0:3d9c67d97d6f 409 /**
emh203 0:3d9c67d97d6f 410 * @} end of FIR_Sparse group
emh203 0:3d9c67d97d6f 411 */