##// END OF EJS Templates
HG_REPOSITORIES » LPP » INSTRUMENTATION » libuc2
RSS

Clone from http://pc-instru.lpp.polytechnique.fr:5000/libuc2

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.
jeandet@pc-de-jeandet3.LAB-LPP.LOCAL - - Load All Authors

File last commit:

r41:27c5438a4566 dev_alexis
r68:104125d87b89 dev_alexis
Show More
arm_fir_interpolate_q15.c
349 lines | 10.2 KiB | text/x-c | CLexer
/ lib / src / stm32f4 / CPU / CMSIS / DSP_Lib / Source / FilteringFunctions / arm_fir_interpolate_q15.c
History | Annotation | Raw |Copy content |Copy permalink
/*-----------------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. July 2011
* $Revision: V1.0.10
*
* Project: CMSIS DSP Library
* Title: arm_fir_interpolate_q15.c
*
* Description: Q15 FIR interpolation.
*
* 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 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 input samples to process per call.
* @return none.
*
* <b>Scaling and Overflow Behavior:</b>
* \par
* 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,
q15_t * pSrc,
q15_t * pDst,
uint32_t blockSize)
{
q15_t *pState = S->pState; /* State pointer */
q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
q15_t *pStateCurnt; /* Points to the current sample of the state */
q15_t *ptr1, *ptr2; /* Temporary pointers for state and coefficient buffers */
#ifndef ARM_MATH_CM0
/* Run the below code for Cortex-M4 and Cortex-M3 */
q63_t sum0; /* Accumulators */
q15_t x0, c0, c1; /* Temporary variables to hold state and coefficient values */
q31_t c, x;
uint32_t i, blkCnt, j, tapCnt; /* Loop counters */
uint16_t phaseLen = S->phaseLength; /* 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 + (phaseLen - 1u);
/* Total number of intput samples */
blkCnt = blockSize;
/* 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 = (uint32_t) phaseLen >> 2u;
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 coefficient */
c1 = *(ptr2);
/* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Pack the coefficients */
#ifndef ARM_MATH_BIG_ENDIAN
c = __PKHBT(c0, c1, 16);
#else
c = __PKHBT(c1, c0, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Read twp consecutive input samples */
x = *__SIMD32(ptr1)++;
/* Perform the multiply-accumulate */
sum0 = __SMLALD(x, c, sum0);
/* Read the coefficient */
c0 = *(ptr2);
/* Upsampling is done by stuffing L-1 zeros between each sample.
* So insted of multiplying zeros with coefficients,
* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Read the coefficient */
c1 = *(ptr2);
/* Increment the coefficient pointer by interpolation factor times. */
ptr2 += S->L;
/* Pack the coefficients */
#ifndef ARM_MATH_BIG_ENDIAN
c = __PKHBT(c0, c1, 16);
#else
c = __PKHBT(c1, c0, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Read twp consecutive input samples */
x = *__SIMD32(ptr1)++;
/* Perform the multiply-accumulate */
sum0 = __SMLALD(x, c, sum0);
/* Decrement the loop counter */
tapCnt--;
}
/* If the polyPhase length is not a multiple of 4, compute the remaining filter taps */
tapCnt = (uint32_t) 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 = __SMLALD(x0, c0, sum0);
/* Decrement the 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 */
pStateCurnt = S->pState;
i = ((uint32_t) phaseLen - 1u) >> 2u;
/* copy data */
while(i > 0u)
{
*__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++;
*__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++;
/* Decrement the loop counter */
i--;
}
i = ((uint32_t) phaseLen - 1u) % 0x04u;
while(i > 0u)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
i--;
}
#else
/* Run the below code for Cortex-M0 */
q63_t sum; /* Accumulator */
q15_t x0, c0; /* Temporary variables to hold state and coefficient values */
uint32_t i, blkCnt, tapCnt; /* Loop counters */
uint16_t phaseLen = S->phaseLength; /* 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 + (phaseLen - 1u);
/* 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);
/* Loop over the polyPhase length */
tapCnt = (uint32_t) 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 += ((q31_t) x0 * c0);
/* Decrement the loop counter */
tapCnt--;
}
/* Store the result after converting to 1.15 format in the destination buffer */
*pDst++ = (q15_t) (__SSAT((sum >> 15), 16));
/* 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 start 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;
i = (uint32_t) phaseLen - 1u;
while(i > 0u)
{
*pStateCurnt++ = *pState++;
/* Decrement the loop counter */
i--;
}
#endif /* #ifndef ARM_MATH_CM0 */
}
/**
* @} end of FIR_Interpolate group
*/