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Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_q31.c')
| -rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_q31.c | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_q31.c b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_q31.c new file mode 100644 index 000000000..689b4d337 --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_interpolate_q31.c @@ -0,0 +1,499 @@ +/*-----------------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_fir_interpolate_q31.c
+*
+* Description: Q31 FIR interpolation.
+*
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*
+* Version 1.1.0 2012/02/15
+* Updated with more optimizations, bug fixes and minor API changes.
+*
+* Version 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated
+*
+* Version 0.0.7 2010/06/10
+* Misra-C changes done
+* ---------------------------------------------------------------------------*/
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupFilters
+ */
+
+/**
+ * @addtogroup FIR_Interpolate
+ * @{
+ */
+
+/**
+ * @brief Processing function for the Q31 FIR interpolator.
+ * @param[in] *S points to an instance of the Q31 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 input samples to process per call.
+ * @return none.
+ *
+ * <b>Scaling and Overflow Behavior:</b>
+ * \par
+ * The function is implemented using an internal 64-bit accumulator.
+ * The accumulator has a 2.62 format and maintains full precision of the intermediate multiplication results but provides only a single guard bit.
+ * Thus, if the accumulator result overflows it wraps around rather than clip.
+ * In order to avoid overflows completely the input signal must be scaled down by <code>1/(numTaps/L)</code>.
+ * since <code>numTaps/L</code> additions occur per output sample.
+ * After all multiply-accumulates are performed, the 2.62 accumulator is truncated to 1.32 format and then saturated to 1.31 format.
+ */
+
+#ifndef ARM_MATH_CM0
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+void arm_fir_interpolate_q31(
+ const arm_fir_interpolate_instance_q31 * S,
+ q31_t * pSrc,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ q31_t *pState = S->pState; /* State pointer */
+ q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q31_t *pStateCurnt; /* Points to the current sample of the state */
+ q31_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
+ q63_t sum0; /* Accumulators */
+ q31_t x0, c0; /* Temporary variables to hold state and coefficient values */
+ uint32_t i, blkCnt, j; /* Loop counters */
+ uint16_t phaseLen = S->phaseLength, tapCnt; /* Length of each polyphase filter component */
+
+ uint32_t blkCntN2;
+ q63_t acc0, acc1;
+ q31_t x1;
+
+ /* S->pState buffer contains previous frame (phaseLen - 1) samples */
+ /* pStateCurnt points to the location where the new input data should be written */
+ pStateCurnt = S->pState + ((q31_t) phaseLen - 1);
+
+ /* Initialise blkCnt */
+ blkCnt = blockSize / 2;
+ blkCntN2 = blockSize - (2 * blkCnt);
+
+ /* Samples loop unrolled by 2 */
+ while(blkCnt > 0u)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCurnt++ = *pSrc++;
+ *pStateCurnt++ = *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;
+
+ /* 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++);
+
+ while(tapCnt > 0u)
+ {
+
+ /* Read the input sample */
+ x1 = *(ptr1++);
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x0 *c0;
+ acc1 += (q63_t) x1 *c0;
+
+
+ /* Read the coefficient */
+ c0 = *(ptr2 + S->L);
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x1 *c0;
+ acc1 += (q63_t) x0 *c0;
+
+
+ /* Read the coefficient */
+ c0 = *(ptr2 + S->L * 2);
+
+ /* Read the input sample */
+ x1 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x0 *c0;
+ acc1 += (q63_t) x1 *c0;
+
+ /* Read the coefficient */
+ c0 = *(ptr2 + S->L * 3);
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x1 *c0;
+ acc1 += (q63_t) x0 *c0;
+
+
+ /* 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 the 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 */
+ x1 = *(ptr1++);
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Perform the multiply-accumulate */
+ acc0 += (q63_t) x0 *c0;
+ acc1 += (q63_t) x1 *c0;
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* update states for next sample processing */
+ x0 = x1;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* The result is in the accumulator, store in the destination buffer. */
+ *pDst = (q31_t) (acc0 >> 31);
+ *(pDst + S->L) = (q31_t) (acc1 >> 31);
+
+
+ pDst++;
+
+ /* 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 + 2;
+
+ pDst += S->L;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* If the blockSize is not a multiple of 2, compute any remaining output samples here.
+ ** No loop unrolling is used. */
+ blkCnt = blkCntN2;
+
+ /* Loop over the blockSize. */
+ while(blkCnt > 0u)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCurnt++ = *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. Unroll by a factor of 4.
+ ** Repeat until we've computed numTaps-(4*S->L) coefficients. */
+ tapCnt = phaseLen >> 2;
+ while(tapCnt > 0u)
+ {
+
+ /* Read the coefficient */
+ c0 = *(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;
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) x0 *c0;
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) x0 *c0;
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) x0 *c0;
+
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) x0 *c0;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* If the polyPhase length is not a multiple of 4, compute the remaining filter taps */
+ tapCnt = phaseLen & 0x3u;
+
+ while(tapCnt > 0u)
+ {
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Read the input sample */
+ x0 = *(ptr1++);
+
+ /* Perform the multiply-accumulate */
+ sum0 += (q63_t) x0 *c0;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* The result is in the accumulator, store in the destination buffer. */
+ *pDst++ = (q31_t) (sum0 >> 31);
+
+ /* 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 */
+ pStateCurnt = S->pState;
+
+ tapCnt = (phaseLen - 1u) >> 2u;
+
+ /* copy data */
+ while(tapCnt > 0u)
+ {
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ tapCnt = (phaseLen - 1u) % 0x04u;
+
+ /* copy data */
+ while(tapCnt > 0u)
+ {
+ *pStateCurnt++ = *pState++;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+}
+
+
+#else
+
+void arm_fir_interpolate_q31(
+ const arm_fir_interpolate_instance_q31 * S,
+ q31_t * pSrc,
+ q31_t * pDst,
+ uint32_t blockSize)
+{
+ q31_t *pState = S->pState; /* State pointer */
+ q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q31_t *pStateCurnt; /* Points to the current sample of the state */
+ q31_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
+
+ /* Run the below code for Cortex-M0 */
+
+ q63_t sum; /* Accumulator */
+ q31_t x0, c0; /* Temporary variables to hold state and coefficient values */
+ uint32_t i, blkCnt; /* Loop counters */
+ uint16_t phaseLen = S->phaseLength, tapCnt; /* Length of each polyphase filter component */
+
+
+ /* S->pState buffer contains previous frame (phaseLen - 1) samples */
+ /* pStateCurnt points to the location where the new input data should be written */
+ pStateCurnt = S->pState + ((q31_t) phaseLen - 1);
+
+ /* Total number of intput samples */
+ blkCnt = blockSize;
+
+ /* Loop over the blockSize. */
+ while(blkCnt > 0u)
+ {
+ /* Copy new input sample into the state buffer */
+ *pStateCurnt++ = *pSrc++;
+
+ /* Loop over the Interpolation factor. */
+ i = S->L;
+
+ while(i > 0u)
+ {
+ /* Set accumulator to zero */
+ sum = 0;
+
+ /* Initialize state pointer */
+ ptr1 = pState;
+
+ /* Initialize coefficient pointer */
+ ptr2 = pCoeffs + (i - 1u);
+
+ tapCnt = phaseLen;
+
+ while(tapCnt > 0u)
+ {
+ /* Read the coefficient */
+ c0 = *(ptr2);
+
+ /* Increment the coefficient pointer by interpolation factor times. */
+ ptr2 += S->L;
+
+ /* Read the input sample */
+ x0 = *ptr1++;
+
+ /* Perform the multiply-accumulate */
+ sum += (q63_t) x0 *c0;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* The result is in the accumulator, store in the destination buffer. */
+ *pDst++ = (q31_t) (sum >> 31);
+
+ /* 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 */
+ pStateCurnt = S->pState;
+
+ tapCnt = phaseLen - 1u;
+
+ /* copy data */
+ while(tapCnt > 0u)
+ {
+ *pStateCurnt++ = *pState++;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+}
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+ /**
+ * @} end of FIR_Interpolate group
+ */
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