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Diffstat (limited to 'fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c')
| -rw-r--r-- | fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c b/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c new file mode 100644 index 0000000..2a08968 --- /dev/null +++ b/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_biquad_cascade_df1_fast_q15.c @@ -0,0 +1,273 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_biquad_cascade_df1_fast_q15.c
+ * Description: Fast processing function for the Q15 Biquad cascade filter
+ *
+ * $Date: 27. January 2017
+ * $Revision: V.1.5.1
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#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
+ */
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