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Removed error on fat32 library, seems now to be able navigate among sectors in...
Removed error on fat32 library, seems now to be able navigate among sectors in both directions. Improved SDLCD drawing performances by almost 1000x.
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arm_lms_q31.c
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/ lib / src / stm32f4 / CPU / CMSIS / DSP_Lib / Source / FilteringFunctions / arm_lms_q31.c
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jeandet@pc-de-jeandet3.LAB-LPP.LOCAL
Added ARM CMSIS for fast math and circle drawing function for ili9328 driver.
 r41 /* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. July 2011
* $Revision: V1.0.10
*
* Project: CMSIS DSP Library
* Title: arm_lms_q31.c
*
* Description: Processing function for the Q31 LMS filter.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* 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 Q31 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 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 clips.
* In order to avoid overflows completely the input signal must be scaled down by
* log2(numTaps) bits.
* The reference signal should not be scaled down.
* After all multiply-accumulates are performed, the 2.62 accumulator is shifted
* and saturated to 1.31 format to yield the final result.
* The output signal and error signal are in 1.31 format.
*
* \par
* In this filter, filter coefficients are updated for each sample and the updation of filter cofficients are saturted.
*/
void arm_lms_q31(
const arm_lms_instance_q31 * S,
q31_t * pSrc,
q31_t * pRef,
q31_t * pOut,
q31_t * pErr,
uint32_t blockSize)
{
q31_t *pState = S->pState; /* State pointer */
uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */
q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
q31_t *pStateCurnt; /* Points to the current sample of the state */
q31_t mu = S->mu; /* Adaptive factor */
q31_t *px; /* Temporary pointer for state */
q31_t *pb; /* Temporary pointer for coefficient buffer */
uint32_t tapCnt, blkCnt; /* Loop counters */
q63_t acc; /* Accumulator */
q31_t e = 0; /* error of data sample */
q31_t alpha; /* Intermediate constant for taps update */
uint8_t shift = (uint8_t) (32u - (S->postShift + 1u)); /* Shift to be applied to the output */
q31_t coef; /* Temporary variable for coef */
/* 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;
#ifndef ARM_MATH_CM0
/* Run the below code for Cortex-M4 and Cortex-M3 */
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 >> 2;
while(tapCnt > 0u)
{
/* Perform the multiply-accumulate */
/* acc += b[N] * x[n-N] */
acc += ((q63_t) (*px++)) * (*pb++);
/* acc += b[N-1] * x[n-N-1] */
acc += ((q63_t) (*px++)) * (*pb++);
/* acc += b[N-2] * x[n-N-2] */
acc += ((q63_t) (*px++)) * (*pb++);
/* acc += b[N-3] * x[n-N-3] */
acc += ((q63_t) (*px++)) * (*pb++);
/* 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) (*px++)) * (*pb++);
/* Decrement the loop counter */
tapCnt--;
}
/* Converting the result to 1.31 format */
/* Store the result from accumulator into the destination buffer. */
acc = (q31_t) (acc >> shift);
*pOut++ = (q31_t) acc;
/* Compute and store error */
e = *pRef++ - (q31_t) acc;
*pErr++ = (q31_t) e;
/* Compute alpha i.e. intermediate constant for taps update */
alpha = (q31_t) (((q63_t) e * mu) >> 31);
/* 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 >> 2;
/* Update filter coefficients */
while(tapCnt > 0u)
{
/* coef is in 2.30 format */
coef = (q31_t) (((q63_t) alpha * (*px++)) >> (32));
/* get coef in 1.31 format by left shifting */
*pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u));
/* update coefficient buffer to next coefficient */
pb++;
coef = (q31_t) (((q63_t) alpha * (*px++)) >> (32));
*pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u));
pb++;
coef = (q31_t) (((q63_t) alpha * (*px++)) >> (32));
*pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u));
pb++;
coef = (q31_t) (((q63_t) alpha * (*px++)) >> (32));
*pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u));
pb++;
/* 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) (((q63_t) alpha * (*px++)) >> (32));
*pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u));
pb++;
/* 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;
/* Loop unrolling for (numTaps - 1u) samples copy */
tapCnt = (numTaps - 1u) >> 2u;
/* copy data */
while(tapCnt > 0u)
{
*pStateCurnt++ = *pState++;
*pStateCurnt++ = *pState++;
*pStateCurnt++ = *pState++;
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
tapCnt--;
}
/* Calculate remaining number of copies */
tapCnt = (numTaps - 1u) % 0x4u;
/* Copy the remaining q31_t data */
while(tapCnt > 0u)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
tapCnt--;
}
#else
/* Run the below code for Cortex-M0 */
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) (*px++)) * (*pb++);
/* Decrement the loop counter */
tapCnt--;
}
/* Converting the result to 1.31 format */
/* Store the result from accumulator into the destination buffer. */
acc = (q31_t) (acc >> shift);
*pOut++ = (q31_t) acc;
/* Compute and store error */
e = *pRef++ - (q31_t) acc;
*pErr++ = (q31_t) e;
/* Weighting factor for the LMS version */
alpha = (q31_t) (((q63_t) e * mu) >> 31);
/* 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 */
coef = (q31_t) (((q63_t) alpha * (*px++)) >> (32));
*pb += (coef << 1u);
pb++;
/* 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
*/