1 /* ----------------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
8 * Title: arm_q7_to_float.c
10 * Description: Converts the elements of the Q7 vector to floating-point vector.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Version 1.0.10 2011/7/15
15 * Big Endian support added and Merged M0 and M3/M4 Source code.
17 * Version 1.0.3 2010/11/29
18 * Re-organized the CMSIS folders and updated documentation.
20 * Version 1.0.2 2010/11/11
21 * Documentation updated.
23 * Version 1.0.1 2010/10/05
24 * Production release and review comments incorporated.
26 * Version 1.0.0 2010/09/20
27 * Production release and review comments incorporated.
28 * ---------------------------------------------------------------------------- */
33 * @ingroup groupSupport
37 * @defgroup q7_to_x Convert 8-bit Integer value
46 * @brief Converts the elements of the Q7 vector to floating-point vector.
47 * @param[in] *pSrc points to the Q7 input vector
48 * @param[out] *pDst points to the floating-point output vector
49 * @param[in] blockSize length of the input vector
54 * The equation used for the conversion process is:
57 * pDst[n] = (float32_t) pSrc[n] / 128; 0 <= n < blockSize.
68 q7_t *pIn = pSrc; /* Src pointer */
69 uint32_t blkCnt; /* loop counter */
74 /* Run the below code for Cortex-M4 and Cortex-M3 */
77 blkCnt = blockSize >> 2u;
79 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
80 ** a second loop below computes the remaining 1 to 3 samples. */
83 /* C = (float32_t) A / 128 */
84 /* convert from q7 to float and then store the results in the destination buffer */
85 *pDst++ = ((float32_t) * pIn++ / 128.0f);
86 *pDst++ = ((float32_t) * pIn++ / 128.0f);
87 *pDst++ = ((float32_t) * pIn++ / 128.0f);
88 *pDst++ = ((float32_t) * pIn++ / 128.0f);
90 /* Decrement the loop counter */
94 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
95 ** No loop unrolling is used. */
96 blkCnt = blockSize % 0x4u;
100 /* Run the below code for Cortex-M0 */
102 /* Loop over blockSize number of values */
105 #endif /* #ifndef ARM_MATH_CM0 */
109 /* C = (float32_t) A / 128 */
110 /* convert from q7 to float and then store the results in the destination buffer */
111 *pDst++ = ((float32_t) * pIn++ / 128.0f);
113 /* Decrement the loop counter */
119 * @} end of q7_to_x group