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Diffstat (limited to 'DSP_Lib/Source/SupportFunctions/arm_q15_to_float.c')
-rw-r--r-- | DSP_Lib/Source/SupportFunctions/arm_q15_to_float.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/DSP_Lib/Source/SupportFunctions/arm_q15_to_float.c b/DSP_Lib/Source/SupportFunctions/arm_q15_to_float.c new file mode 100644 index 0000000..bbaf38c --- /dev/null +++ b/DSP_Lib/Source/SupportFunctions/arm_q15_to_float.c @@ -0,0 +1,134 @@ +/* ---------------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_q15_to_float.c +* +* Description: Converts the elements of the Q15 vector to floating-point vector. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. +* ---------------------------------------------------------------------------- */ + +#include "arm_math.h" + +/** + * @ingroup groupSupport + */ + +/** + * @defgroup q15_to_x Convert 16-bit Integer value + */ + +/** + * @addtogroup q15_to_x + * @{ + */ + + + + +/** + * @brief Converts the elements of the Q15 vector to floating-point vector. + * @param[in] *pSrc points to the Q15 input vector + * @param[out] *pDst points to the floating-point output vector + * @param[in] blockSize length of the input vector + * @return none. + * + * \par Description: + * + * The equation used for the conversion process is: + * + * <pre> + * pDst[n] = (float32_t) pSrc[n] / 32768; 0 <= n < blockSize. + * </pre> + * + */ + + +void arm_q15_to_float( + q15_t * pSrc, + float32_t * pDst, + uint32_t blockSize) +{ + q15_t *pIn = pSrc; /* Src pointer */ + uint32_t blkCnt; /* loop counter */ + + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + /*loop Unrolling */ + blkCnt = blockSize >> 2u; + + /* First part of the processing with loop unrolling. Compute 4 outputs at a time. + ** a second loop below computes the remaining 1 to 3 samples. */ + while(blkCnt > 0u) + { + /* C = (float32_t) A / 32768 */ + /* convert from q15 to float and then store the results in the destination buffer */ + *pDst++ = ((float32_t) * pIn++ / 32768.0f); + *pDst++ = ((float32_t) * pIn++ / 32768.0f); + *pDst++ = ((float32_t) * pIn++ / 32768.0f); + *pDst++ = ((float32_t) * pIn++ / 32768.0f); + + /* Decrement the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x4u; + +#else + + /* Run the below code for Cortex-M0 */ + + /* Loop over blockSize number of values */ + blkCnt = blockSize; + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + + while(blkCnt > 0u) + { + /* C = (float32_t) A / 32768 */ + /* convert from q15 to float and then store the results in the destination buffer */ + *pDst++ = ((float32_t) * pIn++ / 32768.0f); + + /* Decrement the loop counter */ + blkCnt--; + } +} + +/** + * @} end of q15_to_x group + */ |