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author | px4dev <px4@purgatory.org> | 2013-01-06 12:52:05 -0800 |
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committer | px4dev <px4@purgatory.org> | 2013-01-06 12:52:05 -0800 |
commit | 4447282260be0780eb6e36f5e953bf56888a5688 (patch) | |
tree | 3ba1e976d998d433397343b79a0612af52075aef /apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c | |
parent | 659543f852d18197f68fafee5db5671567b74f4b (diff) | |
download | px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.tar.gz px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.tar.bz2 px4-firmware-4447282260be0780eb6e36f5e953bf56888a5688.zip |
Integrate the interesting parts of the CMSIS 3.01 (r3p1) DSP library
Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c new file mode 100644 index 000000000..91237c12d --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_lms_q15.c @@ -0,0 +1,374 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_lms_q15.c
+*
+* Description: Processing function for the Q15 LMS filter.
+*
+* 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 LMS
+ * @{
+ */
+
+ /**
+ * @brief Processing function for Q15 LMS filter.
+ * @param[in] *S points to an instance of the Q15 LMS filter structure.
+ * @param[in] *pSrc points to the block of input data.
+ * @param[in] *pRef points to the block of reference data.
+ * @param[out] *pOut points to the block of output data.
+ * @param[out] *pErr points to the block of error 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.
+ *
+ * \par
+ * In this filter, filter coefficients are updated for each sample and the updation of filter cofficients are saturted.
+ *
+ */
+
+void arm_lms_q15(
+ const arm_lms_instance_q15 * S,
+ q15_t * pSrc,
+ q15_t * pRef,
+ q15_t * pOut,
+ q15_t * pErr,
+ uint32_t blockSize)
+{
+ q15_t *pState = S->pState; /* State pointer */
+ uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */
+ q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q15_t *pStateCurnt; /* Points to the current sample of the state */
+ q15_t mu = S->mu; /* Adaptive factor */
+ q15_t *px; /* Temporary pointer for state */
+ q15_t *pb; /* Temporary pointer for coefficient buffer */
+ uint32_t tapCnt, blkCnt; /* Loop counters */
+ q63_t acc; /* Accumulator */
+ q15_t e = 0; /* error of data sample */
+ q15_t alpha; /* Intermediate constant for taps update */
+ q31_t acc_l, acc_h;
+ int32_t lShift = (15 - (int32_t) S->postShift); /* Post shift */
+ int32_t uShift = (32 - lShift);
+
+
+#ifndef ARM_MATH_CM0
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+ q31_t coef; /* Teporary variable for coefficient */
+
+ /* S->pState points to buffer which contains previous frame (numTaps - 1) samples */
+ /* pStateCurnt points to the location where the new input data should be written */
+ pStateCurnt = &(S->pState[(numTaps - 1u)]);
+
+ /* Initializing blkCnt with blockSize */
+ blkCnt = blockSize;
+
+ while(blkCnt > 0u)
+ {
+ /* Copy the new input sample into the state buffer */
+ *pStateCurnt++ = *pSrc++;
+
+ /* Initialize state pointer */
+ px = pState;
+
+ /* Initialize coefficient pointer */
+ pb = pCoeffs;
+
+ /* Set the accumulator to zero */
+ acc = 0;
+
+ /* Loop unrolling. Process 4 taps at a time. */
+ tapCnt = numTaps >> 2u;
+
+ while(tapCnt > 0u)
+ {
+ /* acc += b[N] * x[n-N] + b[N-1] * x[n-N-1] */
+ /* Perform the multiply-accumulate */
+#ifndef UNALIGNED_SUPPORT_DISABLE
+
+ acc = __SMLALD(*__SIMD32(px)++, (*__SIMD32(pb)++), acc);
+ acc = __SMLALD(*__SIMD32(px)++, (*__SIMD32(pb)++), acc);
+
+#else
+
+ acc += (q63_t) (((q31_t) (*px++) * (*pb++)));
+ acc += (q63_t) (((q31_t) (*px++) * (*pb++)));
+ acc += (q63_t) (((q31_t) (*px++) * (*pb++)));
+ acc += (q63_t) (((q31_t) (*px++) * (*pb++)));
+
+
+#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* If the filter length is not a multiple of 4, compute the remaining filter taps */
+ tapCnt = numTaps % 0x4u;
+
+ while(tapCnt > 0u)
+ {
+ /* Perform the multiply-accumulate */
+ acc += (q63_t) (((q31_t) (*px++) * (*pb++)));
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* Calc lower part of acc */
+ acc_l = acc & 0xffffffff;
+
+ /* Calc upper part of acc */
+ acc_h = (acc >> 32) & 0xffffffff;
+
+ /* Apply shift for lower part of acc and upper part of acc */
+ acc = (uint32_t) acc_l >> lShift | acc_h << uShift;
+
+ /* Converting the result to 1.15 format and saturate the output */
+ acc = __SSAT(acc, 16);
+
+ /* Store the result from accumulator into the destination buffer. */
+ *pOut++ = (q15_t) acc;
+
+ /* Compute and store error */
+ e = *pRef++ - (q15_t) acc;
+
+ *pErr++ = (q15_t) e;
+
+ /* Compute alpha i.e. intermediate constant for taps update */
+ alpha = (q15_t) (((q31_t) e * (mu)) >> 15);
+
+ /* Initialize state pointer */
+ /* Advance state pointer by 1 for the next sample */
+ px = pState++;
+
+ /* Initialize coefficient pointer */
+ pb = pCoeffs;
+
+ /* Loop unrolling. Process 4 taps at a time. */
+ tapCnt = numTaps >> 2u;
+
+ /* Update filter coefficients */
+ while(tapCnt > 0u)
+ {
+ coef = (q31_t) * pb + (((q31_t) alpha * (*px++)) >> 15);
+ *pb++ = (q15_t) __SSAT((coef), 16);
+ coef = (q31_t) * pb + (((q31_t) alpha * (*px++)) >> 15);
+ *pb++ = (q15_t) __SSAT((coef), 16);
+ coef = (q31_t) * pb + (((q31_t) alpha * (*px++)) >> 15);
+ *pb++ = (q15_t) __SSAT((coef), 16);
+ coef = (q31_t) * pb + (((q31_t) alpha * (*px++)) >> 15);
+ *pb++ = (q15_t) __SSAT((coef), 16);
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* If the filter length is not a multiple of 4, compute the remaining filter taps */
+ tapCnt = numTaps % 0x4u;
+
+ while(tapCnt > 0u)
+ {
+ /* Perform the multiply-accumulate */
+ coef = (q31_t) * pb + (((q31_t) alpha * (*px++)) >> 15);
+ *pb++ = (q15_t) __SSAT((coef), 16);
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* Decrement the loop counter */
+ blkCnt--;
+
+ }
+
+ /* Processing is complete. Now copy the last numTaps - 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 pState buffer */
+ pStateCurnt = S->pState;
+
+ /* Calculation of count for copying integer writes */
+ tapCnt = (numTaps - 1u) >> 2;
+
+ while(tapCnt > 0u)
+ {
+
+#ifndef UNALIGNED_SUPPORT_DISABLE
+
+ *__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++;
+ *__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++;
+#else
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+ *pStateCurnt++ = *pState++;
+#endif
+
+ tapCnt--;
+
+ }
+
+ /* Calculation of count for remaining q15_t data */
+ tapCnt = (numTaps - 1u) % 0x4u;
+
+ /* copy data */
+ while(tapCnt > 0u)
+ {
+ *pStateCurnt++ = *pState++;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+#else
+
+ /* Run the below code for Cortex-M0 */
+
+ /* S->pState points to buffer which contains previous frame (numTaps - 1) samples */
+ /* pStateCurnt points to the location where the new input data should be written */
+ pStateCurnt = &(S->pState[(numTaps - 1u)]);
+
+ /* Loop over blockSize number of values */
+ blkCnt = blockSize;
+
+ while(blkCnt > 0u)
+ {
+ /* Copy the new input sample into the state buffer */
+ *pStateCurnt++ = *pSrc++;
+
+ /* Initialize pState pointer */
+ px = pState;
+
+ /* Initialize pCoeffs pointer */
+ pb = pCoeffs;
+
+ /* Set the accumulator to zero */
+ acc = 0;
+
+ /* Loop over numTaps number of values */
+ tapCnt = numTaps;
+
+ while(tapCnt > 0u)
+ {
+ /* Perform the multiply-accumulate */
+ acc += (q63_t) ((q31_t) (*px++) * (*pb++));
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* Calc lower part of acc */
+ acc_l = acc & 0xffffffff;
+
+ /* Calc upper part of acc */
+ acc_h = (acc >> 32) & 0xffffffff;
+
+ /* Apply shift for lower part of acc and upper part of acc */
+ acc = (uint32_t) acc_l >> lShift | acc_h << uShift;
+
+ /* Converting the result to 1.15 format and saturate the output */
+ acc = __SSAT(acc, 16);
+
+ /* Store the result from accumulator into the destination buffer. */
+ *pOut++ = (q15_t) acc;
+
+ /* Compute and store error */
+ e = *pRef++ - (q15_t) acc;
+
+ *pErr++ = (q15_t) e;
+
+ /* Compute alpha i.e. intermediate constant for taps update */
+ alpha = (q15_t) (((q31_t) e * (mu)) >> 15);
+
+ /* Initialize pState pointer */
+ /* Advance state pointer by 1 for the next sample */
+ px = pState++;
+
+ /* Initialize pCoeffs pointer */
+ pb = pCoeffs;
+
+ /* Loop over numTaps number of values */
+ tapCnt = numTaps;
+
+ while(tapCnt > 0u)
+ {
+ /* Perform the multiply-accumulate */
+ *pb++ += (q15_t) (((q31_t) alpha * (*px++)) >> 15);
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+ /* Decrement the loop counter */
+ blkCnt--;
+
+ }
+
+ /* Processing is complete. Now copy the last numTaps - 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 pState buffer */
+ pStateCurnt = S->pState;
+
+ /* Copy (numTaps - 1u) samples */
+ tapCnt = (numTaps - 1u);
+
+ /* Copy the data */
+ while(tapCnt > 0u)
+ {
+ *pStateCurnt++ = *pState++;
+
+ /* Decrement the loop counter */
+ tapCnt--;
+ }
+
+#endif /* #ifndef ARM_MATH_CM0 */
+
+}
+
+/**
+ * @} end of LMS group
+ */
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