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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c | 286 |
1 files changed, 0 insertions, 286 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c b/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c deleted file mode 100644 index a637b03..0000000 --- a/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c +++ /dev/null @@ -1,286 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. March 2015 -* $Revision: V.1.4.5 -* -* Project: CMSIS DSP Library -* Title: arm_biquad_cascade_df1_fast_q15.c -* -* Description: Fast processing function for the -* Q15 Biquad cascade 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 Q15 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 fast version uses a 32-bit accumulator with 2.30 format. - * The accumulator maintains full precision of the intermediate multiplication results but provides only a single guard bit. - * Thus, if the accumulator result overflows it wraps around and distorts the 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). - * The 2.30 accumulator is then shifted by <code>postShift</code> bits and the result truncated to 1.15 format by discarding the low 16 bits. - * - * \par - * Refer to the function <code>arm_biquad_cascade_df1_q15()</code> for a slower implementation of this function which uses 64-bit accumulation to avoid wrap around distortion. Both the slow and the fast versions use the same instance structure. - * Use the function <code>arm_biquad_cascade_df1_init_q15()</code> to initialize the filter structure. - * - */ - -void arm_biquad_cascade_df1_fast_q15( - const arm_biquad_casd_df1_inst_q15 * S, - q15_t * pSrc, - q15_t * pDst, - uint32_t blockSize) -{ - q15_t *pIn = pSrc; /* Source pointer */ - q15_t *pOut = pDst; /* Destination pointer */ - q31_t in; /* Temporary variable to hold input value */ - q31_t out; /* Temporary variable to hold output value */ - q31_t b0; /* Temporary variable to hold bo value */ - q31_t b1, a1; /* Filter coefficients */ - q31_t state_in, state_out; /* Filter state variables */ - q31_t acc; /* Accumulator */ - int32_t shift = (int32_t) (15 - S->postShift); /* Post shift */ - q15_t *pState = S->pState; /* State pointer */ - q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - uint32_t sample, stage = S->numStages; /* Stage loop counter */ - - - - do - { - - /* Read the b0 and 0 coefficients using SIMD */ - b0 = *__SIMD32(pCoeffs)++; - - /* Read the b1 and b2 coefficients using SIMD */ - b1 = *__SIMD32(pCoeffs)++; - - /* Read the a1 and a2 coefficients using SIMD */ - a1 = *__SIMD32(pCoeffs)++; - - /* Read the input state values from the state buffer: x[n-1], x[n-2] */ - state_in = *__SIMD32(pState)++; - - /* Read the output state values from the state buffer: y[n-1], y[n-2] */ - state_out = *__SIMD32(pState)--; - - /* Apply loop unrolling and compute 2 output values simultaneously. */ - /* The variable acc 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] - * acc = b0 * x[n] + b1 * x[n-1] + b2 * x[n-2] + a1 * y[n-1] + a2 * y[n-2] - */ - sample = blockSize >> 1u; - - /* First part of the processing with loop unrolling. Compute 2 outputs at a time. - ** a second loop below computes the remaining 1 sample. */ - while(sample > 0u) - { - - /* Read the input */ - in = *__SIMD32(pIn)++; - - /* out = b0 * x[n] + 0 * 0 */ - out = __SMUAD(b0, in); - /* acc = b1 * x[n-1] + acc += b2 * x[n-2] + out */ - acc = __SMLAD(b1, state_in, out); - /* acc += a1 * y[n-1] + acc += a2 * y[n-2] */ - acc = __SMLAD(a1, state_out, acc); - - /* The result is converted from 3.29 to 1.31 and then saturation is applied */ - out = __SSAT((acc >> shift), 16); - - /* 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 */ - /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ - /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ - -#ifndef ARM_MATH_BIG_ENDIAN - - state_in = __PKHBT(in, state_in, 16); - state_out = __PKHBT(out, state_out, 16); - -#else - - state_in = __PKHBT(state_in >> 16, (in >> 16), 16); - state_out = __PKHBT(state_out >> 16, (out), 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - /* out = b0 * x[n] + 0 * 0 */ - out = __SMUADX(b0, in); - /* acc0 = b1 * x[n-1] , acc0 += b2 * x[n-2] + out */ - acc = __SMLAD(b1, state_in, out); - /* acc += a1 * y[n-1] + acc += a2 * y[n-2] */ - acc = __SMLAD(a1, state_out, acc); - - /* The result is converted from 3.29 to 1.31 and then saturation is applied */ - out = __SSAT((acc >> shift), 16); - - - /* Store the output in the destination buffer. */ - -#ifndef ARM_MATH_BIG_ENDIAN - - *__SIMD32(pOut)++ = __PKHBT(state_out, out, 16); - -#else - - *__SIMD32(pOut)++ = __PKHBT(out, state_out >> 16, 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - /* 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 */ - /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ - /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ - -#ifndef ARM_MATH_BIG_ENDIAN - - state_in = __PKHBT(in >> 16, state_in, 16); - state_out = __PKHBT(out, state_out, 16); - -#else - - state_in = __PKHBT(state_in >> 16, in, 16); - state_out = __PKHBT(state_out >> 16, out, 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - - /* Decrement the loop counter */ - sample--; - - } - - /* If the blockSize is not a multiple of 2, compute any remaining output samples here. - ** No loop unrolling is used. */ - - if((blockSize & 0x1u) != 0u) - { - /* Read the input */ - in = *pIn++; - - /* out = b0 * x[n] + 0 * 0 */ - -#ifndef ARM_MATH_BIG_ENDIAN - - out = __SMUAD(b0, in); - -#else - - out = __SMUADX(b0, in); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - /* acc = b1 * x[n-1], acc += b2 * x[n-2] + out */ - acc = __SMLAD(b1, state_in, out); - /* acc += a1 * y[n-1] + acc += a2 * y[n-2] */ - acc = __SMLAD(a1, state_out, acc); - - /* The result is converted from 3.29 to 1.31 and then saturation is applied */ - out = __SSAT((acc >> shift), 16); - - /* Store the output in the destination buffer. */ - *pOut++ = (q15_t) out; - - /* 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 */ - /* x[n-N], x[n-N-1] are packed together to make state_in of type q31 */ - /* y[n-N], y[n-N-1] are packed together to make state_out of type q31 */ - -#ifndef ARM_MATH_BIG_ENDIAN - - state_in = __PKHBT(in, state_in, 16); - state_out = __PKHBT(out, state_out, 16); - -#else - - state_in = __PKHBT(state_in >> 16, in, 16); - state_out = __PKHBT(state_out >> 16, out, 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - } - - /* The first stage goes from the input buffer to the output buffer. */ - /* Subsequent (numStages - 1) occur in-place in the output buffer */ - pIn = pDst; - - /* Reset the output pointer */ - pOut = pDst; - - /* Store the updated state variables back into the state array */ - *__SIMD32(pState)++ = state_in; - *__SIMD32(pState)++ = state_out; - - - /* Decrement the loop counter */ - stage--; - - } while(stage > 0u); -} - - -/** - * @} end of BiquadCascadeDF1 group - */ |