CMSIS DSP library
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cmsis_dsp/FilteringFunctions/arm_lms_f32.c@5:3762170b6d4d, 2015-11-20 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Nov 20 08:45:18 2015 +0000
- Revision:
- 5:3762170b6d4d
- Parent:
- 3:7a284390b0ce
Synchronized with git revision 2eb940b9a73af188d3004a2575fdfbb05febe62b
Full URL: https://github.com/mbedmicro/mbed/commit/2eb940b9a73af188d3004a2575fdfbb05febe62b/
Added option to build rpc library. closes #1426
Who changed what in which revision?
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emilmont | 1:fdd22bb7aa52 | 1 | /* ---------------------------------------------------------------------- |
mbed_official | 5:3762170b6d4d | 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
emilmont | 1:fdd22bb7aa52 | 3 | * |
mbed_official | 5:3762170b6d4d | 4 | * $Date: 19. March 2015 |
mbed_official | 5:3762170b6d4d | 5 | * $Revision: V.1.4.5 |
emilmont | 1:fdd22bb7aa52 | 6 | * |
emilmont | 2:da51fb522205 | 7 | * Project: CMSIS DSP Library |
emilmont | 2:da51fb522205 | 8 | * Title: arm_lms_f32.c |
emilmont | 1:fdd22bb7aa52 | 9 | * |
emilmont | 2:da51fb522205 | 10 | * Description: Processing function for the floating-point LMS filter. |
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 | * @defgroup LMS Least Mean Square (LMS) Filters |
emilmont | 1:fdd22bb7aa52 | 49 | * |
emilmont | 1:fdd22bb7aa52 | 50 | * LMS filters are a class of adaptive filters that are able to "learn" an unknown transfer functions. |
emilmont | 1:fdd22bb7aa52 | 51 | * LMS filters use a gradient descent method in which the filter coefficients are updated based on the instantaneous error signal. |
emilmont | 1:fdd22bb7aa52 | 52 | * Adaptive filters are often used in communication systems, equalizers, and noise removal. |
emilmont | 1:fdd22bb7aa52 | 53 | * The CMSIS DSP Library contains LMS filter functions that operate on Q15, Q31, and floating-point data types. |
emilmont | 1:fdd22bb7aa52 | 54 | * The library also contains normalized LMS filters in which the filter coefficient adaptation is indepedent of the level of the input signal. |
emilmont | 1:fdd22bb7aa52 | 55 | * |
emilmont | 1:fdd22bb7aa52 | 56 | * An LMS filter consists of two components as shown below. |
emilmont | 1:fdd22bb7aa52 | 57 | * The first component is a standard transversal or FIR filter. |
emilmont | 1:fdd22bb7aa52 | 58 | * The second component is a coefficient update mechanism. |
emilmont | 1:fdd22bb7aa52 | 59 | * The LMS filter has two input signals. |
emilmont | 1:fdd22bb7aa52 | 60 | * The "input" feeds the FIR filter while the "reference input" corresponds to the desired output of the FIR filter. |
emilmont | 1:fdd22bb7aa52 | 61 | * That is, the FIR filter coefficients are updated so that the output of the FIR filter matches the reference input. |
emilmont | 1:fdd22bb7aa52 | 62 | * The filter coefficient update mechanism is based on the difference between the FIR filter output and the reference input. |
emilmont | 1:fdd22bb7aa52 | 63 | * This "error signal" tends towards zero as the filter adapts. |
emilmont | 1:fdd22bb7aa52 | 64 | * The LMS processing functions accept the input and reference input signals and generate the filter output and error signal. |
emilmont | 1:fdd22bb7aa52 | 65 | * \image html LMS.gif "Internal structure of the Least Mean Square filter" |
emilmont | 1:fdd22bb7aa52 | 66 | * |
emilmont | 1:fdd22bb7aa52 | 67 | * The functions operate on blocks of data and each call to the function processes |
emilmont | 1:fdd22bb7aa52 | 68 | * <code>blockSize</code> samples through the filter. |
emilmont | 1:fdd22bb7aa52 | 69 | * <code>pSrc</code> points to input signal, <code>pRef</code> points to reference signal, |
emilmont | 1:fdd22bb7aa52 | 70 | * <code>pOut</code> points to output signal and <code>pErr</code> points to error signal. |
emilmont | 1:fdd22bb7aa52 | 71 | * All arrays contain <code>blockSize</code> values. |
emilmont | 1:fdd22bb7aa52 | 72 | * |
emilmont | 1:fdd22bb7aa52 | 73 | * The functions operate on a block-by-block basis. |
emilmont | 1:fdd22bb7aa52 | 74 | * Internally, the filter coefficients <code>b[n]</code> are updated on a sample-by-sample basis. |
emilmont | 1:fdd22bb7aa52 | 75 | * The convergence of the LMS filter is slower compared to the normalized LMS algorithm. |
emilmont | 1:fdd22bb7aa52 | 76 | * |
emilmont | 1:fdd22bb7aa52 | 77 | * \par Algorithm: |
emilmont | 1:fdd22bb7aa52 | 78 | * The output signal <code>y[n]</code> is computed by a standard FIR filter: |
emilmont | 1:fdd22bb7aa52 | 79 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 80 | * y[n] = b[0] * x[n] + b[1] * x[n-1] + b[2] * x[n-2] + ...+ b[numTaps-1] * x[n-numTaps+1] |
emilmont | 1:fdd22bb7aa52 | 81 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 82 | * |
emilmont | 1:fdd22bb7aa52 | 83 | * \par |
emilmont | 1:fdd22bb7aa52 | 84 | * The error signal equals the difference between the reference signal <code>d[n]</code> and the filter output: |
emilmont | 1:fdd22bb7aa52 | 85 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 86 | * e[n] = d[n] - y[n]. |
emilmont | 1:fdd22bb7aa52 | 87 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 88 | * |
emilmont | 1:fdd22bb7aa52 | 89 | * \par |
emilmont | 1:fdd22bb7aa52 | 90 | * After each sample of the error signal is computed, the filter coefficients <code>b[k]</code> are updated on a sample-by-sample basis: |
emilmont | 1:fdd22bb7aa52 | 91 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 92 | * b[k] = b[k] + e[n] * mu * x[n-k], for k=0, 1, ..., numTaps-1 |
emilmont | 1:fdd22bb7aa52 | 93 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 94 | * where <code>mu</code> is the step size and controls the rate of coefficient convergence. |
emilmont | 1:fdd22bb7aa52 | 95 | *\par |
emilmont | 1:fdd22bb7aa52 | 96 | * In the APIs, <code>pCoeffs</code> points to a coefficient array of size <code>numTaps</code>. |
emilmont | 1:fdd22bb7aa52 | 97 | * Coefficients are stored in time reversed order. |
emilmont | 1:fdd22bb7aa52 | 98 | * \par |
emilmont | 1:fdd22bb7aa52 | 99 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 100 | * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]} |
emilmont | 1:fdd22bb7aa52 | 101 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 102 | * \par |
emilmont | 1:fdd22bb7aa52 | 103 | * <code>pState</code> points to a state array of size <code>numTaps + blockSize - 1</code>. |
emilmont | 1:fdd22bb7aa52 | 104 | * Samples in the state buffer are stored in the order: |
emilmont | 1:fdd22bb7aa52 | 105 | * \par |
emilmont | 1:fdd22bb7aa52 | 106 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 107 | * {x[n-numTaps+1], x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2]....x[0], x[1], ..., x[blockSize-1]} |
emilmont | 1:fdd22bb7aa52 | 108 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 109 | * \par |
emilmont | 1:fdd22bb7aa52 | 110 | * Note that the length of the state buffer exceeds the length of the coefficient array by <code>blockSize-1</code> samples. |
emilmont | 1:fdd22bb7aa52 | 111 | * The increased state buffer length allows circular addressing, which is traditionally used in FIR filters, |
emilmont | 1:fdd22bb7aa52 | 112 | * to be avoided and yields a significant speed improvement. |
emilmont | 1:fdd22bb7aa52 | 113 | * The state variables are updated after each block of data is processed. |
emilmont | 1:fdd22bb7aa52 | 114 | * \par Instance Structure |
emilmont | 1:fdd22bb7aa52 | 115 | * The coefficients and state variables for a filter are stored together in an instance data structure. |
emilmont | 1:fdd22bb7aa52 | 116 | * A separate instance structure must be defined for each filter and |
emilmont | 1:fdd22bb7aa52 | 117 | * coefficient and state arrays cannot be shared among instances. |
emilmont | 1:fdd22bb7aa52 | 118 | * There are separate instance structure declarations for each of the 3 supported data types. |
emilmont | 1:fdd22bb7aa52 | 119 | * |
emilmont | 1:fdd22bb7aa52 | 120 | * \par Initialization Functions |
emilmont | 1:fdd22bb7aa52 | 121 | * There is also an associated initialization function for each data type. |
emilmont | 1:fdd22bb7aa52 | 122 | * The initialization function performs the following operations: |
emilmont | 1:fdd22bb7aa52 | 123 | * - Sets the values of the internal structure fields. |
emilmont | 1:fdd22bb7aa52 | 124 | * - Zeros out the values in the state buffer. |
mbed_official | 3:7a284390b0ce | 125 | * To do this manually without calling the init function, assign the follow subfields of the instance structure: |
mbed_official | 3:7a284390b0ce | 126 | * numTaps, pCoeffs, mu, postShift (not for f32), pState. Also set all of the values in pState to zero. |
mbed_official | 3:7a284390b0ce | 127 | * |
emilmont | 1:fdd22bb7aa52 | 128 | * \par |
emilmont | 1:fdd22bb7aa52 | 129 | * Use of the initialization function is optional. |
emilmont | 1:fdd22bb7aa52 | 130 | * However, if the initialization function is used, then the instance structure cannot be placed into a const data section. |
emilmont | 1:fdd22bb7aa52 | 131 | * To place an instance structure into a const data section, the instance structure must be manually initialized. |
emilmont | 1:fdd22bb7aa52 | 132 | * Set the values in the state buffer to zeros before static initialization. |
emilmont | 1:fdd22bb7aa52 | 133 | * The code below statically initializes each of the 3 different data type filter instance structures |
emilmont | 1:fdd22bb7aa52 | 134 | * <pre> |
emilmont | 1:fdd22bb7aa52 | 135 | * arm_lms_instance_f32 S = {numTaps, pState, pCoeffs, mu}; |
emilmont | 1:fdd22bb7aa52 | 136 | * arm_lms_instance_q31 S = {numTaps, pState, pCoeffs, mu, postShift}; |
emilmont | 1:fdd22bb7aa52 | 137 | * arm_lms_instance_q15 S = {numTaps, pState, pCoeffs, mu, postShift}; |
emilmont | 1:fdd22bb7aa52 | 138 | * </pre> |
emilmont | 1:fdd22bb7aa52 | 139 | * where <code>numTaps</code> is the number of filter coefficients in the filter; <code>pState</code> is the address of the state buffer; |
emilmont | 1:fdd22bb7aa52 | 140 | * <code>pCoeffs</code> is the address of the coefficient buffer; <code>mu</code> is the step size parameter; and <code>postShift</code> is the shift applied to coefficients. |
emilmont | 1:fdd22bb7aa52 | 141 | * |
emilmont | 1:fdd22bb7aa52 | 142 | * \par Fixed-Point Behavior: |
emilmont | 1:fdd22bb7aa52 | 143 | * Care must be taken when using the Q15 and Q31 versions of the LMS filter. |
emilmont | 1:fdd22bb7aa52 | 144 | * The following issues must be considered: |
emilmont | 1:fdd22bb7aa52 | 145 | * - Scaling of coefficients |
emilmont | 1:fdd22bb7aa52 | 146 | * - Overflow and saturation |
emilmont | 1:fdd22bb7aa52 | 147 | * |
emilmont | 1:fdd22bb7aa52 | 148 | * \par Scaling of Coefficients: |
emilmont | 1:fdd22bb7aa52 | 149 | * Filter coefficients are represented as fractional values and |
emilmont | 1:fdd22bb7aa52 | 150 | * coefficients are restricted to lie in the range <code>[-1 +1)</code>. |
emilmont | 1:fdd22bb7aa52 | 151 | * The fixed-point functions have an additional scaling parameter <code>postShift</code>. |
emilmont | 1:fdd22bb7aa52 | 152 | * At the output of the filter's accumulator is a shift register which shifts the result by <code>postShift</code> bits. |
emilmont | 1:fdd22bb7aa52 | 153 | * This essentially scales the filter coefficients by <code>2^postShift</code> and |
emilmont | 1:fdd22bb7aa52 | 154 | * allows the filter coefficients to exceed the range <code>[+1 -1)</code>. |
emilmont | 1:fdd22bb7aa52 | 155 | * The value of <code>postShift</code> is set by the user based on the expected gain through the system being modeled. |
emilmont | 1:fdd22bb7aa52 | 156 | * |
emilmont | 1:fdd22bb7aa52 | 157 | * \par Overflow and Saturation: |
emilmont | 1:fdd22bb7aa52 | 158 | * Overflow and saturation behavior of the fixed-point Q15 and Q31 versions are |
emilmont | 1:fdd22bb7aa52 | 159 | * described separately as part of the function specific documentation below. |
emilmont | 1:fdd22bb7aa52 | 160 | */ |
emilmont | 1:fdd22bb7aa52 | 161 | |
emilmont | 1:fdd22bb7aa52 | 162 | /** |
emilmont | 1:fdd22bb7aa52 | 163 | * @addtogroup LMS |
emilmont | 1:fdd22bb7aa52 | 164 | * @{ |
emilmont | 1:fdd22bb7aa52 | 165 | */ |
emilmont | 1:fdd22bb7aa52 | 166 | |
emilmont | 1:fdd22bb7aa52 | 167 | /** |
emilmont | 1:fdd22bb7aa52 | 168 | * @details |
emilmont | 1:fdd22bb7aa52 | 169 | * This function operates on floating-point data types. |
emilmont | 1:fdd22bb7aa52 | 170 | * |
emilmont | 1:fdd22bb7aa52 | 171 | * @brief Processing function for floating-point LMS filter. |
emilmont | 1:fdd22bb7aa52 | 172 | * @param[in] *S points to an instance of the floating-point LMS filter structure. |
emilmont | 1:fdd22bb7aa52 | 173 | * @param[in] *pSrc points to the block of input data. |
emilmont | 1:fdd22bb7aa52 | 174 | * @param[in] *pRef points to the block of reference data. |
emilmont | 1:fdd22bb7aa52 | 175 | * @param[out] *pOut points to the block of output data. |
emilmont | 1:fdd22bb7aa52 | 176 | * @param[out] *pErr points to the block of error data. |
emilmont | 1:fdd22bb7aa52 | 177 | * @param[in] blockSize number of samples to process. |
emilmont | 1:fdd22bb7aa52 | 178 | * @return none. |
emilmont | 1:fdd22bb7aa52 | 179 | */ |
emilmont | 1:fdd22bb7aa52 | 180 | |
emilmont | 1:fdd22bb7aa52 | 181 | void arm_lms_f32( |
emilmont | 1:fdd22bb7aa52 | 182 | const arm_lms_instance_f32 * S, |
emilmont | 1:fdd22bb7aa52 | 183 | float32_t * pSrc, |
emilmont | 1:fdd22bb7aa52 | 184 | float32_t * pRef, |
emilmont | 1:fdd22bb7aa52 | 185 | float32_t * pOut, |
emilmont | 1:fdd22bb7aa52 | 186 | float32_t * pErr, |
emilmont | 1:fdd22bb7aa52 | 187 | uint32_t blockSize) |
emilmont | 1:fdd22bb7aa52 | 188 | { |
emilmont | 1:fdd22bb7aa52 | 189 | float32_t *pState = S->pState; /* State pointer */ |
emilmont | 1:fdd22bb7aa52 | 190 | float32_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 191 | float32_t *pStateCurnt; /* Points to the current sample of the state */ |
emilmont | 1:fdd22bb7aa52 | 192 | float32_t *px, *pb; /* Temporary pointers for state and coefficient buffers */ |
emilmont | 1:fdd22bb7aa52 | 193 | float32_t mu = S->mu; /* Adaptive factor */ |
emilmont | 1:fdd22bb7aa52 | 194 | uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ |
emilmont | 1:fdd22bb7aa52 | 195 | uint32_t tapCnt, blkCnt; /* Loop counters */ |
emilmont | 1:fdd22bb7aa52 | 196 | float32_t sum, e, d; /* accumulator, error, reference data sample */ |
emilmont | 1:fdd22bb7aa52 | 197 | float32_t w = 0.0f; /* weight factor */ |
emilmont | 1:fdd22bb7aa52 | 198 | |
emilmont | 1:fdd22bb7aa52 | 199 | e = 0.0f; |
emilmont | 1:fdd22bb7aa52 | 200 | d = 0.0f; |
emilmont | 1:fdd22bb7aa52 | 201 | |
emilmont | 1:fdd22bb7aa52 | 202 | /* S->pState points to state array which contains previous frame (numTaps - 1) samples */ |
emilmont | 1:fdd22bb7aa52 | 203 | /* pStateCurnt points to the location where the new input data should be written */ |
emilmont | 1:fdd22bb7aa52 | 204 | pStateCurnt = &(S->pState[(numTaps - 1u)]); |
emilmont | 1:fdd22bb7aa52 | 205 | |
emilmont | 1:fdd22bb7aa52 | 206 | blkCnt = blockSize; |
emilmont | 1:fdd22bb7aa52 | 207 | |
emilmont | 1:fdd22bb7aa52 | 208 | |
mbed_official | 3:7a284390b0ce | 209 | #ifndef ARM_MATH_CM0_FAMILY |
emilmont | 1:fdd22bb7aa52 | 210 | |
emilmont | 1:fdd22bb7aa52 | 211 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
emilmont | 1:fdd22bb7aa52 | 212 | |
emilmont | 1:fdd22bb7aa52 | 213 | while(blkCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 214 | { |
emilmont | 1:fdd22bb7aa52 | 215 | /* Copy the new input sample into the state buffer */ |
emilmont | 1:fdd22bb7aa52 | 216 | *pStateCurnt++ = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 217 | |
emilmont | 1:fdd22bb7aa52 | 218 | /* Initialize pState pointer */ |
emilmont | 1:fdd22bb7aa52 | 219 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 220 | |
emilmont | 1:fdd22bb7aa52 | 221 | /* Initialize coeff pointer */ |
emilmont | 1:fdd22bb7aa52 | 222 | pb = (pCoeffs); |
emilmont | 1:fdd22bb7aa52 | 223 | |
emilmont | 1:fdd22bb7aa52 | 224 | /* Set the accumulator to zero */ |
emilmont | 1:fdd22bb7aa52 | 225 | sum = 0.0f; |
emilmont | 1:fdd22bb7aa52 | 226 | |
emilmont | 1:fdd22bb7aa52 | 227 | /* Loop unrolling. Process 4 taps at a time. */ |
emilmont | 1:fdd22bb7aa52 | 228 | tapCnt = numTaps >> 2; |
emilmont | 1:fdd22bb7aa52 | 229 | |
emilmont | 1:fdd22bb7aa52 | 230 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 231 | { |
emilmont | 1:fdd22bb7aa52 | 232 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 233 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 234 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 235 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 236 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 237 | |
emilmont | 1:fdd22bb7aa52 | 238 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 239 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 240 | } |
emilmont | 1:fdd22bb7aa52 | 241 | |
emilmont | 1:fdd22bb7aa52 | 242 | /* If the filter length is not a multiple of 4, compute the remaining filter taps */ |
emilmont | 1:fdd22bb7aa52 | 243 | tapCnt = numTaps % 0x4u; |
emilmont | 1:fdd22bb7aa52 | 244 | |
emilmont | 1:fdd22bb7aa52 | 245 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 246 | { |
emilmont | 1:fdd22bb7aa52 | 247 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 248 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 249 | |
emilmont | 1:fdd22bb7aa52 | 250 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 251 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 252 | } |
emilmont | 1:fdd22bb7aa52 | 253 | |
emilmont | 1:fdd22bb7aa52 | 254 | /* The result in the accumulator, store in the destination buffer. */ |
emilmont | 1:fdd22bb7aa52 | 255 | *pOut++ = sum; |
emilmont | 1:fdd22bb7aa52 | 256 | |
emilmont | 1:fdd22bb7aa52 | 257 | /* Compute and store error */ |
emilmont | 1:fdd22bb7aa52 | 258 | d = (float32_t) (*pRef++); |
emilmont | 1:fdd22bb7aa52 | 259 | e = d - sum; |
emilmont | 1:fdd22bb7aa52 | 260 | *pErr++ = e; |
emilmont | 1:fdd22bb7aa52 | 261 | |
emilmont | 1:fdd22bb7aa52 | 262 | /* Calculation of Weighting factor for the updating filter coefficients */ |
emilmont | 1:fdd22bb7aa52 | 263 | w = e * mu; |
emilmont | 1:fdd22bb7aa52 | 264 | |
emilmont | 1:fdd22bb7aa52 | 265 | /* Initialize pState pointer */ |
emilmont | 1:fdd22bb7aa52 | 266 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 267 | |
emilmont | 1:fdd22bb7aa52 | 268 | /* Initialize coeff pointer */ |
emilmont | 1:fdd22bb7aa52 | 269 | pb = (pCoeffs); |
emilmont | 1:fdd22bb7aa52 | 270 | |
emilmont | 1:fdd22bb7aa52 | 271 | /* Loop unrolling. Process 4 taps at a time. */ |
emilmont | 1:fdd22bb7aa52 | 272 | tapCnt = numTaps >> 2; |
emilmont | 1:fdd22bb7aa52 | 273 | |
emilmont | 1:fdd22bb7aa52 | 274 | /* Update filter coefficients */ |
emilmont | 1:fdd22bb7aa52 | 275 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 276 | { |
emilmont | 1:fdd22bb7aa52 | 277 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 278 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 279 | pb++; |
emilmont | 1:fdd22bb7aa52 | 280 | |
emilmont | 1:fdd22bb7aa52 | 281 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 282 | pb++; |
emilmont | 1:fdd22bb7aa52 | 283 | |
emilmont | 1:fdd22bb7aa52 | 284 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 285 | pb++; |
emilmont | 1:fdd22bb7aa52 | 286 | |
emilmont | 1:fdd22bb7aa52 | 287 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 288 | pb++; |
emilmont | 1:fdd22bb7aa52 | 289 | |
emilmont | 1:fdd22bb7aa52 | 290 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 291 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 292 | } |
emilmont | 1:fdd22bb7aa52 | 293 | |
emilmont | 1:fdd22bb7aa52 | 294 | /* If the filter length is not a multiple of 4, compute the remaining filter taps */ |
emilmont | 1:fdd22bb7aa52 | 295 | tapCnt = numTaps % 0x4u; |
emilmont | 1:fdd22bb7aa52 | 296 | |
emilmont | 1:fdd22bb7aa52 | 297 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 298 | { |
emilmont | 1:fdd22bb7aa52 | 299 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 300 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 301 | pb++; |
emilmont | 1:fdd22bb7aa52 | 302 | |
emilmont | 1:fdd22bb7aa52 | 303 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 304 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 305 | } |
emilmont | 1:fdd22bb7aa52 | 306 | |
emilmont | 1:fdd22bb7aa52 | 307 | /* Advance state pointer by 1 for the next sample */ |
emilmont | 1:fdd22bb7aa52 | 308 | pState = pState + 1; |
emilmont | 1:fdd22bb7aa52 | 309 | |
emilmont | 1:fdd22bb7aa52 | 310 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 311 | blkCnt--; |
emilmont | 1:fdd22bb7aa52 | 312 | } |
emilmont | 1:fdd22bb7aa52 | 313 | |
emilmont | 1:fdd22bb7aa52 | 314 | |
emilmont | 1:fdd22bb7aa52 | 315 | /* Processing is complete. Now copy the last numTaps - 1 samples to the |
emilmont | 1:fdd22bb7aa52 | 316 | satrt of the state buffer. This prepares the state buffer for the |
emilmont | 1:fdd22bb7aa52 | 317 | next function call. */ |
emilmont | 1:fdd22bb7aa52 | 318 | |
emilmont | 1:fdd22bb7aa52 | 319 | /* Points to the start of the pState buffer */ |
emilmont | 1:fdd22bb7aa52 | 320 | pStateCurnt = S->pState; |
emilmont | 1:fdd22bb7aa52 | 321 | |
emilmont | 1:fdd22bb7aa52 | 322 | /* Loop unrolling for (numTaps - 1u) samples copy */ |
emilmont | 1:fdd22bb7aa52 | 323 | tapCnt = (numTaps - 1u) >> 2u; |
emilmont | 1:fdd22bb7aa52 | 324 | |
emilmont | 1:fdd22bb7aa52 | 325 | /* copy data */ |
emilmont | 1:fdd22bb7aa52 | 326 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 327 | { |
emilmont | 1:fdd22bb7aa52 | 328 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 329 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 330 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 331 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 332 | |
emilmont | 1:fdd22bb7aa52 | 333 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 334 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 335 | } |
emilmont | 1:fdd22bb7aa52 | 336 | |
emilmont | 1:fdd22bb7aa52 | 337 | /* Calculate remaining number of copies */ |
emilmont | 1:fdd22bb7aa52 | 338 | tapCnt = (numTaps - 1u) % 0x4u; |
emilmont | 1:fdd22bb7aa52 | 339 | |
emilmont | 1:fdd22bb7aa52 | 340 | /* Copy the remaining q31_t data */ |
emilmont | 1:fdd22bb7aa52 | 341 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 342 | { |
emilmont | 1:fdd22bb7aa52 | 343 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 344 | |
emilmont | 1:fdd22bb7aa52 | 345 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 346 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 347 | } |
emilmont | 1:fdd22bb7aa52 | 348 | |
emilmont | 1:fdd22bb7aa52 | 349 | #else |
emilmont | 1:fdd22bb7aa52 | 350 | |
emilmont | 1:fdd22bb7aa52 | 351 | /* Run the below code for Cortex-M0 */ |
emilmont | 1:fdd22bb7aa52 | 352 | |
emilmont | 1:fdd22bb7aa52 | 353 | while(blkCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 354 | { |
emilmont | 1:fdd22bb7aa52 | 355 | /* Copy the new input sample into the state buffer */ |
emilmont | 1:fdd22bb7aa52 | 356 | *pStateCurnt++ = *pSrc++; |
emilmont | 1:fdd22bb7aa52 | 357 | |
emilmont | 1:fdd22bb7aa52 | 358 | /* Initialize pState pointer */ |
emilmont | 1:fdd22bb7aa52 | 359 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 360 | |
emilmont | 1:fdd22bb7aa52 | 361 | /* Initialize pCoeffs pointer */ |
emilmont | 1:fdd22bb7aa52 | 362 | pb = pCoeffs; |
emilmont | 1:fdd22bb7aa52 | 363 | |
emilmont | 1:fdd22bb7aa52 | 364 | /* Set the accumulator to zero */ |
emilmont | 1:fdd22bb7aa52 | 365 | sum = 0.0f; |
emilmont | 1:fdd22bb7aa52 | 366 | |
emilmont | 1:fdd22bb7aa52 | 367 | /* Loop over numTaps number of values */ |
emilmont | 1:fdd22bb7aa52 | 368 | tapCnt = numTaps; |
emilmont | 1:fdd22bb7aa52 | 369 | |
emilmont | 1:fdd22bb7aa52 | 370 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 371 | { |
emilmont | 1:fdd22bb7aa52 | 372 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 373 | sum += (*px++) * (*pb++); |
emilmont | 1:fdd22bb7aa52 | 374 | |
emilmont | 1:fdd22bb7aa52 | 375 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 376 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 377 | } |
emilmont | 1:fdd22bb7aa52 | 378 | |
emilmont | 1:fdd22bb7aa52 | 379 | /* The result is stored in the destination buffer. */ |
emilmont | 1:fdd22bb7aa52 | 380 | *pOut++ = sum; |
emilmont | 1:fdd22bb7aa52 | 381 | |
emilmont | 1:fdd22bb7aa52 | 382 | /* Compute and store error */ |
emilmont | 1:fdd22bb7aa52 | 383 | d = (float32_t) (*pRef++); |
emilmont | 1:fdd22bb7aa52 | 384 | e = d - sum; |
emilmont | 1:fdd22bb7aa52 | 385 | *pErr++ = e; |
emilmont | 1:fdd22bb7aa52 | 386 | |
emilmont | 1:fdd22bb7aa52 | 387 | /* Weighting factor for the LMS version */ |
emilmont | 1:fdd22bb7aa52 | 388 | w = e * mu; |
emilmont | 1:fdd22bb7aa52 | 389 | |
emilmont | 1:fdd22bb7aa52 | 390 | /* Initialize pState pointer */ |
emilmont | 1:fdd22bb7aa52 | 391 | px = pState; |
emilmont | 1:fdd22bb7aa52 | 392 | |
emilmont | 1:fdd22bb7aa52 | 393 | /* Initialize pCoeffs pointer */ |
emilmont | 1:fdd22bb7aa52 | 394 | pb = pCoeffs; |
emilmont | 1:fdd22bb7aa52 | 395 | |
emilmont | 1:fdd22bb7aa52 | 396 | /* Loop over numTaps number of values */ |
emilmont | 1:fdd22bb7aa52 | 397 | tapCnt = numTaps; |
emilmont | 1:fdd22bb7aa52 | 398 | |
emilmont | 1:fdd22bb7aa52 | 399 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 400 | { |
emilmont | 1:fdd22bb7aa52 | 401 | /* Perform the multiply-accumulate */ |
emilmont | 1:fdd22bb7aa52 | 402 | *pb = *pb + (w * (*px++)); |
emilmont | 1:fdd22bb7aa52 | 403 | pb++; |
emilmont | 1:fdd22bb7aa52 | 404 | |
emilmont | 1:fdd22bb7aa52 | 405 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 406 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 407 | } |
emilmont | 1:fdd22bb7aa52 | 408 | |
emilmont | 1:fdd22bb7aa52 | 409 | /* Advance state pointer by 1 for the next sample */ |
emilmont | 1:fdd22bb7aa52 | 410 | pState = pState + 1; |
emilmont | 1:fdd22bb7aa52 | 411 | |
emilmont | 1:fdd22bb7aa52 | 412 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 413 | blkCnt--; |
emilmont | 1:fdd22bb7aa52 | 414 | } |
emilmont | 1:fdd22bb7aa52 | 415 | |
emilmont | 1:fdd22bb7aa52 | 416 | |
emilmont | 1:fdd22bb7aa52 | 417 | /* Processing is complete. Now copy the last numTaps - 1 samples to the |
emilmont | 1:fdd22bb7aa52 | 418 | * start of the state buffer. This prepares the state buffer for the |
emilmont | 1:fdd22bb7aa52 | 419 | * next function call. */ |
emilmont | 1:fdd22bb7aa52 | 420 | |
emilmont | 1:fdd22bb7aa52 | 421 | /* Points to the start of the pState buffer */ |
emilmont | 1:fdd22bb7aa52 | 422 | pStateCurnt = S->pState; |
emilmont | 1:fdd22bb7aa52 | 423 | |
emilmont | 1:fdd22bb7aa52 | 424 | /* Copy (numTaps - 1u) samples */ |
emilmont | 1:fdd22bb7aa52 | 425 | tapCnt = (numTaps - 1u); |
emilmont | 1:fdd22bb7aa52 | 426 | |
emilmont | 1:fdd22bb7aa52 | 427 | /* Copy the data */ |
emilmont | 1:fdd22bb7aa52 | 428 | while(tapCnt > 0u) |
emilmont | 1:fdd22bb7aa52 | 429 | { |
emilmont | 1:fdd22bb7aa52 | 430 | *pStateCurnt++ = *pState++; |
emilmont | 1:fdd22bb7aa52 | 431 | |
emilmont | 1:fdd22bb7aa52 | 432 | /* Decrement the loop counter */ |
emilmont | 1:fdd22bb7aa52 | 433 | tapCnt--; |
emilmont | 1:fdd22bb7aa52 | 434 | } |
emilmont | 1:fdd22bb7aa52 | 435 | |
mbed_official | 3:7a284390b0ce | 436 | #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
emilmont | 1:fdd22bb7aa52 | 437 | |
emilmont | 1:fdd22bb7aa52 | 438 | } |
emilmont | 1:fdd22bb7aa52 | 439 | |
emilmont | 1:fdd22bb7aa52 | 440 | /** |
emilmont | 1:fdd22bb7aa52 | 441 | * @} end of LMS group |
emilmont | 1:fdd22bb7aa52 | 442 | */ |