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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q31.c')
| -rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q31.c | 305 |
1 files changed, 0 insertions, 305 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q31.c b/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q31.c deleted file mode 100644 index b135b2e..0000000 --- a/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q31.c +++ /dev/null @@ -1,305 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. October 2015 -* $Revision: V.1.4.5 a -* -* Project: CMSIS DSP Library -* Title: arm_biquad_cascade_df1_fast_q31.c -* -* Description: Processing function for the -* Q31 Fast Biquad cascade DirectFormI(DF1) filter. -* -* Target Processor: Cortex-M4/Cortex-M3 -* -* Redistribution and use in source and binary forms, with or without -* modification, are permitted provided that the following conditions -* are met: -* - Redistributions of source code must retain the above copyright -* notice, this list of conditions and the following disclaimer. -* - Redistributions in binary form must reproduce the above copyright -* notice, this list of conditions and the following disclaimer in -* the documentation and/or other materials provided with the -* distribution. -* - Neither the name of ARM LIMITED nor the names of its contributors -* may be used to endorse or promote products derived from this -* software without specific prior written permission. -* -* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -* POSSIBILITY OF SUCH DAMAGE. -* -------------------------------------------------------------------- */ - -#include "arm_math.h" - -/** - * @ingroup groupFilters - */ - -/** - * @addtogroup BiquadCascadeDF1 - * @{ - */ - -/** - * @details - * - * @param[in] *S points to an instance of the Q31 Biquad cascade structure. - * @param[in] *pSrc points to the block of input data. - * @param[out] *pDst points to the block of output data. - * @param[in] blockSize number of samples to process per call. - * @return none. - * - * <b>Scaling and Overflow Behavior:</b> - * \par - * This function is optimized for speed at the expense of fixed-point precision and overflow protection. - * The result of each 1.31 x 1.31 multiplication is truncated to 2.30 format. - * These intermediate results are added to a 2.30 accumulator. - * Finally, the accumulator is saturated and converted to a 1.31 result. - * The fast version has the same overflow behavior as the standard version and provides less precision since it discards the low 32 bits of each multiplication result. - * In order to avoid overflows completely the input signal must be scaled down by two bits and lie in the range [-0.25 +0.25). Use the intialization function - * arm_biquad_cascade_df1_init_q31() to initialize filter structure. - * - * \par - * Refer to the function <code>arm_biquad_cascade_df1_q31()</code> for a slower implementation of this function which uses 64-bit accumulation to provide higher precision. Both the slow and the fast versions use the same instance structure. - * Use the function <code>arm_biquad_cascade_df1_init_q31()</code> to initialize the filter structure. - */ - -void arm_biquad_cascade_df1_fast_q31( - const arm_biquad_casd_df1_inst_q31 * S, - q31_t * pSrc, - q31_t * pDst, - uint32_t blockSize) -{ - q31_t acc = 0; /* accumulator */ - q31_t Xn1, Xn2, Yn1, Yn2; /* Filter state variables */ - q31_t b0, b1, b2, a1, a2; /* Filter coefficients */ - q31_t *pIn = pSrc; /* input pointer initialization */ - q31_t *pOut = pDst; /* output pointer initialization */ - q31_t *pState = S->pState; /* pState pointer initialization */ - q31_t *pCoeffs = S->pCoeffs; /* coeff pointer initialization */ - q31_t Xn; /* temporary input */ - int32_t shift = (int32_t) S->postShift + 1; /* Shift to be applied to the output */ - uint32_t sample, stage = S->numStages; /* loop counters */ - - - do - { - /* Reading the coefficients */ - b0 = *pCoeffs++; - b1 = *pCoeffs++; - b2 = *pCoeffs++; - a1 = *pCoeffs++; - a2 = *pCoeffs++; - - /* Reading the state values */ - Xn1 = pState[0]; - Xn2 = pState[1]; - Yn1 = pState[2]; - Yn2 = pState[3]; - - /* Apply loop unrolling and compute 4 output values simultaneously. */ - /* The variables acc ... acc3 hold output values that are being computed: - * - * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] - */ - - sample = blockSize >> 2u; - - /* First part of the processing with loop unrolling. Compute 4 outputs at a time. - ** a second loop below computes the remaining 1 to 3 samples. */ - while(sample > 0u) - { - /* Read the input */ - Xn = *pIn; - - /* acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ - /* acc = b0 * x[n] */ - /*acc = (q31_t) (((q63_t) b1 * Xn1) >> 32);*/ - mult_32x32_keep32_R(acc, b1, Xn1); - /* acc += b1 * x[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b0 * (Xn))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b0, Xn); - /* acc += b[2] * x[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b2 * (Xn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b2, Xn2); - /* acc += a1 * y[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a1 * (Yn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a1, Yn1); - /* acc += a2 * y[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a2 * (Yn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a2, Yn2); - - /* The result is converted to 1.31 , Yn2 variable is reused */ - Yn2 = acc << shift; - - /* Read the second input */ - Xn2 = *(pIn + 1u); - - /* Store the output in the destination buffer. */ - *pOut = Yn2; - - /* acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ - /* acc = b0 * x[n] */ - /*acc = (q31_t) (((q63_t) b0 * (Xn2)) >> 32);*/ - mult_32x32_keep32_R(acc, b0, Xn2); - /* acc += b1 * x[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b1 * (Xn))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b1, Xn); - /* acc += b[2] * x[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b2 * (Xn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b2, Xn1); - /* acc += a1 * y[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a1 * (Yn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a1, Yn2); - /* acc += a2 * y[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a2 * (Yn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a2, Yn1); - - /* The result is converted to 1.31, Yn1 variable is reused */ - Yn1 = acc << shift; - - /* Read the third input */ - Xn1 = *(pIn + 2u); - - /* Store the output in the destination buffer. */ - *(pOut + 1u) = Yn1; - - /* acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ - /* acc = b0 * x[n] */ - /*acc = (q31_t) (((q63_t) b0 * (Xn1)) >> 32);*/ - mult_32x32_keep32_R(acc, b0, Xn1); - /* acc += b1 * x[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b1 * (Xn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b1, Xn2); - /* acc += b[2] * x[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b2 * (Xn))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b2, Xn); - /* acc += a1 * y[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a1 * (Yn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a1, Yn1); - /* acc += a2 * y[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a2 * (Yn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a2, Yn2); - - /* The result is converted to 1.31, Yn2 variable is reused */ - Yn2 = acc << shift; - - /* Read the forth input */ - Xn = *(pIn + 3u); - - /* Store the output in the destination buffer. */ - *(pOut + 2u) = Yn2; - pIn += 4u; - - /* acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ - /* acc = b0 * x[n] */ - /*acc = (q31_t) (((q63_t) b0 * (Xn)) >> 32);*/ - mult_32x32_keep32_R(acc, b0, Xn); - /* acc += b1 * x[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b1 * (Xn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b1, Xn1); - /* acc += b[2] * x[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b2 * (Xn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b2, Xn2); - /* acc += a1 * y[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a1 * (Yn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a1, Yn2); - /* acc += a2 * y[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a2 * (Yn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a2, Yn1); - - /* Every time after the output is computed state should be updated. */ - /* The states should be updated as: */ - /* Xn2 = Xn1 */ - Xn2 = Xn1; - - /* The result is converted to 1.31, Yn1 variable is reused */ - Yn1 = acc << shift; - - /* Xn1 = Xn */ - Xn1 = Xn; - - /* Store the output in the destination buffer. */ - *(pOut + 3u) = Yn1; - pOut += 4u; - - /* decrement the loop counter */ - sample--; - } - - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ - sample = (blockSize & 0x3u); - - while(sample > 0u) - { - /* Read the input */ - Xn = *pIn++; - - /* acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] */ - /* acc = b0 * x[n] */ - /*acc = (q31_t) (((q63_t) b0 * (Xn)) >> 32);*/ - mult_32x32_keep32_R(acc, b0, Xn); - /* acc += b1 * x[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b1 * (Xn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b1, Xn1); - /* acc += b[2] * x[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) b2 * (Xn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, b2, Xn2); - /* acc += a1 * y[n-1] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a1 * (Yn1))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a1, Yn1); - /* acc += a2 * y[n-2] */ - /*acc = (q31_t) ((((q63_t) acc << 32) + ((q63_t) a2 * (Yn2))) >> 32);*/ - multAcc_32x32_keep32_R(acc, a2, Yn2); - - /* The result is converted to 1.31 */ - acc = acc << shift; - - /* Every time after the output is computed state should be updated. */ - /* The states should be updated as: */ - /* Xn2 = Xn1 */ - /* Xn1 = Xn */ - /* Yn2 = Yn1 */ - /* Yn1 = acc */ - Xn2 = Xn1; - Xn1 = Xn; - Yn2 = Yn1; - Yn1 = acc; - - /* Store the output in the destination buffer. */ - *pOut++ = acc; - - /* decrement the loop counter */ - sample--; - } - - /* The first stage goes from the input buffer to the output buffer. */ - /* Subsequent stages occur in-place in the output buffer */ - pIn = pDst; - - /* Reset to destination pointer */ - pOut = pDst; - - /* Store the updated state variables back into the pState array */ - *pState++ = Xn1; - *pState++ = Xn2; - *pState++ = Yn1; - *pState++ = Yn2; - - } while(--stage); -} - -/** - * @} end of BiquadCascadeDF1 group - */ |