/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_q7_to_float.c * Description: Converts the elements of the Q7 vector to floating-point vector * * $Date: 27. January 2017 * $Revision: V.1.5.1 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the License); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an AS IS BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "arm_math.h" /** * @ingroup groupSupport */ /** * @defgroup q7_to_x Convert 8-bit Integer value */ /** * @addtogroup q7_to_x * @{ */ /** * @brief Converts the elements of the Q7 vector to floating-point vector. * @param[in] *pSrc points to the Q7 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: * *
 * 	pDst[n] = (float32_t) pSrc[n] / 128;   0 <= n < blockSize.
 * 
* */ void arm_q7_to_float( q7_t * pSrc, float32_t * pDst, uint32_t blockSize) { q7_t *pIn = pSrc; /* Src pointer */ uint32_t blkCnt; /* loop counter */ #if defined (ARM_MATH_DSP) /* 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 / 128 */ /* convert from q7 to float and then store the results in the destination buffer */ *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); *pDst++ = ((float32_t) * pIn++ / 128.0f); /* 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 /* #if defined (ARM_MATH_DSP) */ while (blkCnt > 0U) { /* C = (float32_t) A / 128 */ /* convert from q7 to float and then store the results in the destination buffer */ *pDst++ = ((float32_t) * pIn++ / 128.0f); /* Decrement the loop counter */ blkCnt--; } } /** * @} end of q7_to_x group */