diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_interpolate_q15.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_interpolate_q15.c | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_interpolate_q15.c b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_interpolate_q15.c new file mode 100644 index 0000000..ad5194a --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_interpolate_q15.c @@ -0,0 +1,479 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_fir_interpolate_q15.c
+ * Description: Q15 FIR interpolation
+ *
+ * $Date: 18. March 2019
+ * $Revision: V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 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 FIR_Interpolate
+ @{
+ */
+
+/**
+ @brief Processing function for the Q15 FIR interpolator.
+ @param[in] S points to an instance of the Q15 FIR interpolator 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
+
+ @par Scaling and Overflow Behavior
+ The function is implemented using a 64-bit internal accumulator.
+ Both coefficients and state variables are represented in 1.15 format and multiplications yield a 2.30 result.
+ The 2.30 intermediate results are accumulated in a 64-bit accumulator in 34.30 format.
+ There is no risk of internal overflow with this approach and the full precision of intermediate multiplications is preserved.
+ After all additions have been performed, the accumulator is truncated to 34.15 format by discarding low 15 bits.
+ Lastly, the accumulator is saturated to yield a result in 1.15 format.
+ */
+
+void arm_fir_interpolate_q15(
+ const arm_fir_interpolate_instance_q15 * S,
+ const q15_t * pSrc,
+ q15_t * pDst,
+ uint32_t blockSize)
+{
+#if (1)
+//#if !defined(ARM_MATH_CM0_FAMILY)
+
+ q15_t *pState = S->pState; /* State pointer */
+ const q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q15_t *pStateCur; /* Points to the current sample of the state */
+ q15_t *ptr1; /* Temporary pointer for state buffer */
+ const q15_t *ptr2; /* Temporary pointer for coefficient buffer */
+ q63_t sum0; /* Accumulators */
+ uint32_t i, blkCnt, tapCnt; /* Loop counters */
+ uint32_t phaseLen = S->phaseLength; /* Length of each polyphase filter component */
+ uint32_t j;
+
+#if defined (ARM_MATH_LOOPUNROLL)
+ q63_t acc0, acc1, acc2, acc3;
+ q15_t x0, x1, x2, x3;
+ q15_t c0, c1, c2, c3;
+#endif
+
+ /* S->pState buffer contains previous frame (phaseLen - 1) samples */
+ /* pStateCur points to the location where the new input data should be written */
+ pStateCur = S->pState + (phaseLen - 1U);
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCur++ = *pSrc++;
+ *pStateCur++ = *pSrc++;
+ *pStateCur++ = *pSrc++;
+ *pStateCur++ = *pSrc++;
+
+ /* Address modifier index of coefficient buffer */
+ j = 1U;
+
+ /* Loop over the Interpolation factor. */
+ i = (S->L);
+
+ while (i > 0U)
+ {
+ /* Set accumulator to zero */
+ acc0 = 0;
+ acc1 = 0;
+ acc2 = 0;
+ acc3 = 0;
+
+ /* Initialize state pointer */
+ ptr1 = pState;
+
+ /* Initialize coefficient pointer */
+ ptr2 = pCoeffs + (S->L - j);
+
+ /* Loop over the polyPhase length. Unroll by a factor of 4.
+ Repeat until we've computed numTaps-(4*S->L) coefficients. */
+ tapCnt = phaseLen >> 2U;
+
+ x0 = *(ptr1++);
+ x1 = *(ptr1++);
+ x2 = *(ptr1++);
+
+ while (tapCnt > 0U)
+ {
+ /* Read the input sample */
+ x3 = *(ptr1++);
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x0 * c0;
+ acc1 += (q63_t) x1 * c0;
+ acc2 += (q63_t) x2 * c0;
+ acc3 += (q63_t) x3 * c0;
+
+ /* Read the coefficient */
+ c1 = *(ptr2 + S->L);
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x1 * c1;
+ acc1 += (q63_t) x2 * c1;
+ acc2 += (q63_t) x3 * c1;
+ acc3 += (q63_t) x0 * c1;
+
+ /* Read the coefficient */
+ c2 = *(ptr2 + S->L * 2);
+
+ /* Read the input sample */
+ x1 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x2 * c2;
+ acc1 += (q63_t) x3 * c2;
+ acc2 += (q63_t) x0 * c2;
+ acc3 += (q63_t) x1 * c2;
+
+ /* Read the coefficient */
+ c3 = *(ptr2 + S->L * 3);
+
+ /* Read the input sample */
+ x2 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x3 * c3;
+ acc1 += (q63_t) x0 * c3;
+ acc2 += (q63_t) x1 * c3;
+ acc3 += (q63_t) x2 * c3;
+
+
+ /* Upsampling is done by stuffing L-1 zeros between each sample.
+ * So instead of multiplying zeros with coefficients,
+ * Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += 4 * S->L;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* If the polyPhase length is not a multiple of 4, compute the remaining filter taps */
+ tapCnt = phaseLen % 0x4U;
+
+ while (tapCnt > 0U)
+ {
+ /* Read the input sample */
+ x3 = *(ptr1++);
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x0 * c0;
+ acc1 += (q63_t) x1 * c0;
+ acc2 += (q63_t) x2 * c0;
+ acc3 += (q63_t) x3 * c0;
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* update states for next sample processing */
+ x0 = x1;
+ x1 = x2;
+ x2 = x3;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* The result is in the accumulator, store in the destination buffer. */
+ *(pDst ) = (q15_t) (__SSAT((acc0 >> 15), 16));
+ *(pDst + S->L) = (q15_t) (__SSAT((acc1 >> 15), 16));
+ *(pDst + 2 * S->L) = (q15_t) (__SSAT((acc2 >> 15), 16));
+ *(pDst + 3 * S->L) = (q15_t) (__SSAT((acc3 >> 15), 16));
+
+ pDst++;
+
+ /* Increment the address modifier index of coefficient buffer */
+ j++;
+
+ /* Decrement loop counter */
+ i--;
+ }
+
+ /* Advance the state pointer by 1
+ * to process the next group of interpolation factor number samples */
+ pState = pState + 4;
+
+ pDst += S->L * 3;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = blockSize % 0x4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCur++ = *pSrc++;
+
+ /* Address modifier index of coefficient buffer */
+ j = 1U;
+
+ /* Loop over the Interpolation factor. */
+ i = S->L;
+ while (i > 0U)
+ {
+ /* Set accumulator to zero */
+ sum0 = 0;
+
+ /* Initialize state pointer */
+ ptr1 = pState;
+
+ /* Initialize coefficient pointer */
+ ptr2 = pCoeffs + (S->L - j);
+
+ /* Loop over the polyPhase length.
+ Repeat until we've computed numTaps-(4*S->L) coefficients. */
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ tapCnt = phaseLen >> 2U;
+
+ while (tapCnt > 0U)
+ {
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) *ptr1++ * *ptr2;
+
+ /* Upsampling is done by stuffing L-1 zeros between each sample.
+ * So instead of multiplying zeros with coefficients,
+ * Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ sum0 += (q63_t) *ptr1++ * *ptr2;
+ ptr2 += S->L;
+
+ sum0 += (q63_t) *ptr1++ * *ptr2;
+ ptr2 += S->L;
+
+ sum0 += (q63_t) *ptr1++ * *ptr2;
+ ptr2 += S->L;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ tapCnt = phaseLen % 0x4U;
+
+#else
+
+ /* Initialize tapCnt with number of samples */
+ tapCnt = phaseLen;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (tapCnt > 0U)
+ {
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) *ptr1++ * *ptr2;
+
+ /* Upsampling is done by stuffing L-1 zeros between each sample.
+ * So instead of multiplying zeros with coefficients,
+ * Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* The result is in the accumulator, store in the destination buffer. */
+ *pDst++ = (q15_t) (__SSAT((sum0 >> 15), 16));
+
+ /* Increment the address modifier index of coefficient buffer */
+ j++;
+
+ /* Decrement the loop counter */
+ i--;
+ }
+
+ /* Advance the state pointer by 1
+ * to process the next group of interpolation factor number samples */
+ pState = pState + 1;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* Processing is complete.
+ Now copy the last phaseLen - 1 samples to the satrt of the state buffer.
+ This prepares the state buffer for the next function call. */
+
+ /* Points to the start of the state buffer */
+ pStateCur = S->pState;
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ tapCnt = (phaseLen - 1U) >> 2U;
+
+ /* copy data */
+ while (tapCnt > 0U)
+ {
+ write_q15x2_ia (&pStateCur, read_q15x2_ia (&pState));
+ write_q15x2_ia (&pStateCur, read_q15x2_ia (&pState));
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ tapCnt = (phaseLen - 1U) % 0x04U;
+
+#else
+
+ /* Initialize tapCnt with number of samples */
+ tapCnt = (phaseLen - 1U);
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ /* Copy data */
+ while (tapCnt > 0U)
+ {
+ *pStateCur++ = *pState++;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+#else
+/* alternate version for CM0_FAMILY */
+
+ q15_t *pState = S->pState; /* State pointer */
+ const q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q15_t *pStateCur; /* Points to the current sample of the state */
+ q15_t *ptr1; /* Temporary pointer for state buffer */
+ const q15_t *ptr2; /* Temporary pointer for coefficient buffer */
+ q63_t sum0; /* Accumulators */
+ uint32_t i, blkCnt, tapCnt; /* Loop counters */
+ uint32_t phaseLen = S->phaseLength; /* Length of each polyphase filter component */
+
+ /* S->pState buffer contains previous frame (phaseLen - 1) samples */
+ /* pStateCur points to the location where the new input data should be written */
+ pStateCur = S->pState + (phaseLen - 1U);
+
+ /* Total number of intput samples */
+ blkCnt = blockSize;
+
+ /* Loop over the blockSize. */
+ while (blkCnt > 0U)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCur++ = *pSrc++;
+
+ /* Loop over the Interpolation factor. */
+ i = S->L;
+
+ while (i > 0U)
+ {
+ /* Set accumulator to zero */
+ sum0 = 0;
+
+ /* Initialize state pointer */
+ ptr1 = pState;
+
+ /* Initialize coefficient pointer */
+ ptr2 = pCoeffs + (i - 1U);
+
+ /* Loop over the polyPhase length */
+ tapCnt = phaseLen;
+
+ while (tapCnt > 0U)
+ {
+ /* Perform the multiply-accumulate */
+ sum0 += ((q63_t) *ptr1++ * *ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* Store the result after converting to 1.15 format in the destination buffer. */
+ *pDst++ = (q15_t) (__SSAT((sum0 >> 15), 16));
+
+ /* Decrement loop counter */
+ i--;
+ }
+
+ /* Advance the state pointer by 1
+ * to process the next group of interpolation factor number samples */
+ pState = pState + 1;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Processing is complete.
+ ** Now copy the last phaseLen - 1 samples to the start of the state buffer.
+ ** This prepares the state buffer for the next function call. */
+
+ /* Points to the start of the state buffer */
+ pStateCur = S->pState;
+
+ tapCnt = phaseLen - 1U;
+
+ /* Copy data */
+ while (tapCnt > 0U)
+ {
+ *pStateCur++ = *pState++;
+
+ /* Decrement loop counter */
+ tapCnt--;
+ }
+
+#endif /* #if !defined(ARM_MATH_CM0_FAMILY) */
+
+}
+
+/**
+ @} end of FIR_Interpolate group
+ */
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