diff options
Diffstat (limited to 'fw/midi-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_lattice_q31.c')
| -rw-r--r-- | fw/midi-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_lattice_q31.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/fw/midi-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_lattice_q31.c b/fw/midi-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_lattice_q31.c new file mode 100644 index 0000000..9d52bbc --- /dev/null +++ b/fw/midi-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_lattice_q31.c @@ -0,0 +1,341 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_fir_lattice_q31.c
+ * Description: Q31 FIR lattice filter processing function
+ *
+ * $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 FIR_Lattice
+ * @{
+ */
+
+
+/**
+ * @brief Processing function for the Q31 FIR lattice filter.
+ * @param[in] *S points to an instance of the Q31 FIR lattice 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.
+ *
+ * @details
+ * <b>Scaling and Overflow Behavior:</b>
+ * In order to avoid overflows the input signal must be scaled down by 2*log2(numStages) bits.
+ */
+
+#if defined (ARM_MATH_DSP)
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+void arm_fir_lattice_q31(
+ const arm_fir_lattice_instance_q31 * S,
+ q31_t * pSrc,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ q31_t *pState; /* State pointer */
+ q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q31_t *px; /* temporary state pointer */
+ q31_t *pk; /* temporary coefficient pointer */
+ q31_t fcurr1, fnext1, gcurr1 = 0, gnext1; /* temporary variables for first sample in loop unrolling */
+ q31_t fcurr2, fnext2, gnext2; /* temporary variables for second sample in loop unrolling */
+ uint32_t numStages = S->numStages; /* Length of the filter */
+ uint32_t blkCnt, stageCnt; /* temporary variables for counts */
+ q31_t k;
+
+ pState = &S->pState[0];
+
+ blkCnt = 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 (blkCnt > 0U)
+ {
+ /* f0(n) = x(n) */
+ fcurr1 = *pSrc++;
+
+ /* f0(n) = x(n) */
+ fcurr2 = *pSrc++;
+
+ /* Initialize coeff pointer */
+ pk = (pCoeffs);
+
+ /* Initialize state pointer */
+ px = pState;
+
+ /* read g0(n - 1) from state buffer */
+ gcurr1 = *px;
+
+ /* Read the reflection coefficient */
+ k = *pk++;
+
+ /* for sample 1 processing */
+ /* f1(n) = f0(n) + K1 * g0(n-1) */
+ fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32);
+
+ /* g1(n) = f0(n) * K1 + g0(n-1) */
+ gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32);
+ fnext1 = fcurr1 + (fnext1 << 1U);
+ gnext1 = gcurr1 + (gnext1 << 1U);
+
+ /* for sample 1 processing */
+ /* f1(n) = f0(n) + K1 * g0(n-1) */
+ fnext2 = (q31_t) (((q63_t) fcurr1 * k) >> 32);
+
+ /* g1(n) = f0(n) * K1 + g0(n-1) */
+ gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32);
+ fnext2 = fcurr2 + (fnext2 << 1U);
+ gnext2 = fcurr1 + (gnext2 << 1U);
+
+ /* save g1(n) in state buffer */
+ *px++ = fcurr2;
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr1 = fnext1;
+ fcurr2 = fnext2;
+
+ stageCnt = (numStages - 1U);
+
+ /* stage loop */
+ while (stageCnt > 0U)
+ {
+
+ /* Read the reflection coefficient */
+ k = *pk++;
+
+ /* read g2(n) from state buffer */
+ gcurr1 = *px;
+
+ /* save g1(n) in state buffer */
+ *px++ = gnext2;
+
+ /* Sample processing for K2, K3.... */
+ /* f2(n) = f1(n) + K2 * g1(n-1) */
+ fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32);
+ fnext2 = (q31_t) (((q63_t) gnext1 * k) >> 32);
+
+ fnext1 = fcurr1 + (fnext1 << 1U);
+ fnext2 = fcurr2 + (fnext2 << 1U);
+
+ /* g2(n) = f1(n) * K2 + g1(n-1) */
+ gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32);
+ gnext2 = gnext1 + (gnext2 << 1U);
+
+ /* g2(n) = f1(n) * K2 + g1(n-1) */
+ gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32);
+ gnext1 = gcurr1 + (gnext1 << 1U);
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr1 = fnext1;
+ fcurr2 = fnext2;
+
+ stageCnt--;
+
+ }
+
+ /* y(n) = fN(n) */
+ *pDst++ = fcurr1;
+ *pDst++ = fcurr2;
+
+ blkCnt--;
+
+ }
+
+ /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
+ ** No loop unrolling is used. */
+ blkCnt = blockSize % 0x2U;
+
+ while (blkCnt > 0U)
+ {
+ /* f0(n) = x(n) */
+ fcurr1 = *pSrc++;
+
+ /* Initialize coeff pointer */
+ pk = (pCoeffs);
+
+ /* Initialize state pointer */
+ px = pState;
+
+ /* read g0(n - 1) from state buffer */
+ gcurr1 = *px;
+
+ /* Read the reflection coefficient */
+ k = *pk++;
+
+ /* for sample 1 processing */
+ /* f1(n) = f0(n) + K1 * g0(n-1) */
+ fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32);
+ fnext1 = fcurr1 + (fnext1 << 1U);
+
+ /* g1(n) = f0(n) * K1 + g0(n-1) */
+ gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32);
+ gnext1 = gcurr1 + (gnext1 << 1U);
+
+ /* save g1(n) in state buffer */
+ *px++ = fcurr1;
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr1 = fnext1;
+
+ stageCnt = (numStages - 1U);
+
+ /* stage loop */
+ while (stageCnt > 0U)
+ {
+ /* Read the reflection coefficient */
+ k = *pk++;
+
+ /* read g2(n) from state buffer */
+ gcurr1 = *px;
+
+ /* save g1(n) in state buffer */
+ *px++ = gnext1;
+
+ /* Sample processing for K2, K3.... */
+ /* f2(n) = f1(n) + K2 * g1(n-1) */
+ fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32);
+ fnext1 = fcurr1 + (fnext1 << 1U);
+
+ /* g2(n) = f1(n) * K2 + g1(n-1) */
+ gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32);
+ gnext1 = gcurr1 + (gnext1 << 1U);
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr1 = fnext1;
+
+ stageCnt--;
+
+ }
+
+
+ /* y(n) = fN(n) */
+ *pDst++ = fcurr1;
+
+ blkCnt--;
+
+ }
+
+
+}
+
+
+#else
+
+/* Run the below code for Cortex-M0 */
+
+void arm_fir_lattice_q31(
+ const arm_fir_lattice_instance_q31 * S,
+ q31_t * pSrc,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ q31_t *pState; /* State pointer */
+ q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q31_t *px; /* temporary state pointer */
+ q31_t *pk; /* temporary coefficient pointer */
+ q31_t fcurr, fnext, gcurr, gnext; /* temporary variables */
+ uint32_t numStages = S->numStages; /* Length of the filter */
+ uint32_t blkCnt, stageCnt; /* temporary variables for counts */
+
+ pState = &S->pState[0];
+
+ blkCnt = blockSize;
+
+ while (blkCnt > 0U)
+ {
+ /* f0(n) = x(n) */
+ fcurr = *pSrc++;
+
+ /* Initialize coeff pointer */
+ pk = (pCoeffs);
+
+ /* Initialize state pointer */
+ px = pState;
+
+ /* read g0(n-1) from state buffer */
+ gcurr = *px;
+
+ /* for sample 1 processing */
+ /* f1(n) = f0(n) + K1 * g0(n-1) */
+ fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr;
+ /* g1(n) = f0(n) * K1 + g0(n-1) */
+ gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr;
+ /* save g1(n) in state buffer */
+ *px++ = fcurr;
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr = fnext;
+
+ stageCnt = (numStages - 1U);
+
+ /* stage loop */
+ while (stageCnt > 0U)
+ {
+ /* read g2(n) from state buffer */
+ gcurr = *px;
+
+ /* save g1(n) in state buffer */
+ *px++ = gnext;
+
+ /* Sample processing for K2, K3.... */
+ /* f2(n) = f1(n) + K2 * g1(n-1) */
+ fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr;
+ /* g2(n) = f1(n) * K2 + g1(n-1) */
+ gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr;
+
+ /* f1(n) is saved in fcurr1
+ for next stage processing */
+ fcurr = fnext;
+
+ stageCnt--;
+
+ }
+
+ /* y(n) = fN(n) */
+ *pDst++ = fcurr;
+
+ blkCnt--;
+
+ }
+
+}
+
+#endif /* #if defined (ARM_MATH_DSP) */
+
+
+/**
+ * @} end of FIR_Lattice group
+ */
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