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Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_f32.c')
-rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_f32.c | 359 |
1 files changed, 0 insertions, 359 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_f32.c b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_f32.c deleted file mode 100644 index 1462d51e7b..0000000000 --- a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_f32.c +++ /dev/null @@ -1,359 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2013 ARM Limited. All rights reserved. -* -* $Date: 17. January 2013 -* -* Project: CMSIS DSP Library -* Title: arm_biquad_cascade_df2T_f32.c -* -* Description: Processing function for the floating-point transposed -* direct form II Biquad cascade filter. -* -* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 -* -* 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 -*/ - -/** -* @defgroup BiquadCascadeDF2T Biquad Cascade IIR Filters Using a Direct Form II Transposed Structure -* -* This set of functions implements arbitrary order recursive (IIR) filters using a transposed direct form II structure. -* The filters are implemented as a cascade of second order Biquad sections. -* These functions provide a slight memory savings as compared to the direct form I Biquad filter functions. -* Only floating-point data is supported. -* -* This function operate on blocks of input and output data and each call to the function -* processes <code>blockSize</code> samples through the filter. -* <code>pSrc</code> points to the array of input data and -* <code>pDst</code> points to the array of output data. -* Both arrays contain <code>blockSize</code> values. -* -* \par Algorithm -* Each Biquad stage implements a second order filter using the difference equation: -* <pre> -* y[n] = b0 * x[n] + d1 -* d1 = b1 * x[n] + a1 * y[n] + d2 -* d2 = b2 * x[n] + a2 * y[n] -* </pre> -* where d1 and d2 represent the two state values. -* -* \par -* A Biquad filter using a transposed Direct Form II structure is shown below. -* \image html BiquadDF2Transposed.gif "Single transposed Direct Form II Biquad" -* Coefficients <code>b0, b1, and b2 </code> multiply the input signal <code>x[n]</code> and are referred to as the feedforward coefficients. -* Coefficients <code>a1</code> and <code>a2</code> multiply the output signal <code>y[n]</code> and are referred to as the feedback coefficients. -* Pay careful attention to the sign of the feedback coefficients. -* Some design tools flip the sign of the feedback coefficients: -* <pre> -* y[n] = b0 * x[n] + d1; -* d1 = b1 * x[n] - a1 * y[n] + d2; -* d2 = b2 * x[n] - a2 * y[n]; -* </pre> -* In this case the feedback coefficients <code>a1</code> and <code>a2</code> must be negated when used with the CMSIS DSP Library. -* -* \par -* Higher order filters are realized as a cascade of second order sections. -* <code>numStages</code> refers to the number of second order stages used. -* For example, an 8th order filter would be realized with <code>numStages=4</code> second order stages. -* A 9th order filter would be realized with <code>numStages=5</code> second order stages with the -* coefficients for one of the stages configured as a first order filter (<code>b2=0</code> and <code>a2=0</code>). -* -* \par -* <code>pState</code> points to the state variable array. -* Each Biquad stage has 2 state variables <code>d1</code> and <code>d2</code>. -* The state variables are arranged in the <code>pState</code> array as: -* <pre> -* {d11, d12, d21, d22, ...} -* </pre> -* where <code>d1x</code> refers to the state variables for the first Biquad and -* <code>d2x</code> refers to the state variables for the second Biquad. -* The state array has a total length of <code>2*numStages</code> values. -* The state variables are updated after each block of data is processed; the coefficients are untouched. -* -* \par -* The CMSIS library contains Biquad filters in both Direct Form I and transposed Direct Form II. -* The advantage of the Direct Form I structure is that it is numerically more robust for fixed-point data types. -* That is why the Direct Form I structure supports Q15 and Q31 data types. -* The transposed Direct Form II structure, on the other hand, requires a wide dynamic range for the state variables <code>d1</code> and <code>d2</code>. -* Because of this, the CMSIS library only has a floating-point version of the Direct Form II Biquad. -* The advantage of the Direct Form II Biquad is that it requires half the number of state variables, 2 rather than 4, per Biquad stage. -* -* \par Instance Structure -* The coefficients and state variables for a filter are stored together in an instance data structure. -* A separate instance structure must be defined for each filter. -* Coefficient arrays may be shared among several instances while state variable arrays cannot be shared. -* -* \par Init Functions -* There is also an associated initialization function. -* The initialization function performs following operations: -* - Sets the values of the internal structure fields. -* - Zeros out the values in the state buffer. -* To do this manually without calling the init function, assign the follow subfields of the instance structure: -* numStages, pCoeffs, pState. Also set all of the values in pState to zero. -* -* \par -* Use of the initialization function is optional. -* However, if the initialization function is used, then the instance structure cannot be placed into a const data section. -* To place an instance structure into a const data section, the instance structure must be manually initialized. -* Set the values in the state buffer to zeros before static initialization. -* For example, to statically initialize the instance structure use -* <pre> -* arm_biquad_cascade_df2T_instance_f32 S1 = {numStages, pState, pCoeffs}; -* </pre> -* where <code>numStages</code> is the number of Biquad stages in the filter; <code>pState</code> is the address of the state buffer. -* <code>pCoeffs</code> is the address of the coefficient buffer; -* -*/ - -/** -* @addtogroup BiquadCascadeDF2T -* @{ -*/ - -/** -* @brief Processing function for the floating-point transposed direct form II Biquad cascade filter. -* @param[in] *S points to an instance of the filter data 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. -* @return none. -*/ - - -LOW_OPTIMIZATION_ENTER -void arm_biquad_cascade_df2T_f32( -const arm_biquad_cascade_df2T_instance_f32 * S, -float32_t * pSrc, -float32_t * pDst, -uint32_t blockSize) -{ - - float32_t *pIn = pSrc; /* source pointer */ - float32_t *pOut = pDst; /* destination pointer */ - float32_t *pState = S->pState; /* State pointer */ - float32_t *pCoeffs = S->pCoeffs; /* coefficient pointer */ - float32_t acc1; /* accumulator */ - float32_t b0, b1, b2, a1, a2; /* Filter coefficients */ - float32_t Xn1; /* temporary input */ - float32_t d1, d2; /* state variables */ - uint32_t sample, stage = S->numStages; /* loop counters */ - -#ifndef ARM_MATH_CM0_FAMILY_FAMILY - - float32_t Xn2, Xn3, Xn4; /* Input State variables */ - float32_t acc2, acc3, acc4; /* accumulator */ - - - float32_t p0, p1, p2, p3, p4, A1; - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - do - { - /* Reading the coefficients */ - b0 = *pCoeffs++; - b1 = *pCoeffs++; - b2 = *pCoeffs++; - a1 = *pCoeffs++; - a2 = *pCoeffs++; - - - /*Reading the state values */ - d1 = pState[0]; - d2 = pState[1]; - - /* Apply loop unrolling and compute 4 output values simultaneously. */ - 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) { - - /* y[n] = b0 * x[n] + d1 */ - /* d1 = b1 * x[n] + a1 * y[n] + d2 */ - /* d2 = b2 * x[n] + a2 * y[n] */ - - /* Read the four inputs */ - Xn1 = pIn[0]; - Xn2 = pIn[1]; - Xn3 = pIn[2]; - Xn4 = pIn[3]; - pIn += 4; - - p0 = b0 * Xn1; - p1 = b1 * Xn1; - acc1 = p0 + d1; - p0 = b0 * Xn2; - p3 = a1 * acc1; - p2 = b2 * Xn1; - A1 = p1 + p3; - p4 = a2 * acc1; - d1 = A1 + d2; - d2 = p2 + p4; - - p1 = b1 * Xn2; - acc2 = p0 + d1; - p0 = b0 * Xn3; - p3 = a1 * acc2; - p2 = b2 * Xn2; - A1 = p1 + p3; - p4 = a2 * acc2; - d1 = A1 + d2; - d2 = p2 + p4; - - p1 = b1 * Xn3; - acc3 = p0 + d1; - p0 = b0 * Xn4; - p3 = a1 * acc3; - p2 = b2 * Xn3; - A1 = p1 + p3; - p4 = a2 * acc3; - d1 = A1 + d2; - d2 = p2 + p4; - - acc4 = p0 + d1; - p1 = b1 * Xn4; - p3 = a1 * acc4; - p2 = b2 * Xn4; - A1 = p1 + p3; - p4 = a2 * acc4; - d1 = A1 + d2; - d2 = p2 + p4; - - pOut[0] = acc1; - pOut[1] = acc2; - pOut[2] = acc3; - pOut[3] = acc4; - pOut += 4; - - sample--; - } - - sample = blockSize & 0x3u; - while(sample > 0u) { - Xn1 = *pIn++; - - p0 = b0 * Xn1; - p1 = b1 * Xn1; - acc1 = p0 + d1; - p3 = a1 * acc1; - p2 = b2 * Xn1; - A1 = p1 + p3; - p4 = a2 * acc1; - d1 = A1 + d2; - d2 = p2 + p4; - - *pOut++ = acc1; - - sample--; - } - - /* Store the updated state variables back into the state array */ - *pState++ = d1; - *pState++ = d2; - - /* The current stage input is given as the output to the next stage */ - pIn = pDst; - - /*Reset the output working pointer */ - pOut = pDst; - - /* decrement the loop counter */ - stage--; - - } while(stage > 0u); - -#else - - /* Run the below code for Cortex-M0 */ - - do - { - /* Reading the coefficients */ - b0 = *pCoeffs++; - b1 = *pCoeffs++; - b2 = *pCoeffs++; - a1 = *pCoeffs++; - a2 = *pCoeffs++; - - /*Reading the state values */ - d1 = pState[0]; - d2 = pState[1]; - - - sample = blockSize; - - while(sample > 0u) - { - /* Read the input */ - Xn1 = *pIn++; - - /* y[n] = b0 * x[n] + d1 */ - acc1 = (b0 * Xn1) + d1; - - /* Store the result in the accumulator in the destination buffer. */ - *pOut++ = acc1; - - /* Every time after the output is computed state should be updated. */ - /* d1 = b1 * x[n] + a1 * y[n] + d2 */ - d1 = ((b1 * Xn1) + (a1 * acc1)) + d2; - - /* d2 = b2 * x[n] + a2 * y[n] */ - d2 = (b2 * Xn1) + (a2 * acc1); - - /* decrement the loop counter */ - sample--; - } - - /* Store the updated state variables back into the state array */ - *pState++ = d1; - *pState++ = d2; - - /* The current stage input is given as the output to the next stage */ - pIn = pDst; - - /*Reset the output working pointer */ - pOut = pDst; - - /* decrement the loop counter */ - stage--; - - } while(stage > 0u); - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - -} -LOW_OPTIMIZATION_EXIT - -/** - * @} end of BiquadCascadeDF2T group - */ |