1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_q7_to_f64.c
4 * Description: Converts the elements of the Q7 vector to 64 bit floating-point vector
5 *
6 * $Date: 18 August 2022
7 * $Revision: V1.0.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2022 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29 #include "dsp/support_functions.h"
30
31 /**
32 @ingroup groupSupport
33 */
34
35 /**
36 * @defgroup q7_to_x Convert 8-bit fixed point value
37 */
38
39 /**
40 @addtogroup q7_to_x
41 @{
42 */
43
44 /**
45 @brief Converts the elements of the Q7 vector to 64 bit floating-point vector.
46 @param[in] pSrc points to the Q7 input vector
47 @param[out] pDst points to the 64 bit floating-point output vector
48 @param[in] blockSize number of samples in each vector
49
50 @par Details
51 The equation used for the conversion process is:
52 <pre>
53 pDst[n] = (float64_t) pSrc[n] / 128; 0 <= n < blockSize.
54 </pre>
55 */
arm_q7_to_f64(const q7_t * pSrc,float64_t * pDst,uint32_t blockSize)56 void arm_q7_to_f64(
57 const q7_t * pSrc,
58 float64_t * pDst,
59 uint32_t blockSize)
60 {
61 uint32_t blkCnt; /* Loop counter */
62 const q7_t *pIn = pSrc; /* Source pointer */
63
64 #if defined (ARM_MATH_LOOPUNROLL)
65
66 /* Loop unrolling: Compute 4 outputs at a time */
67 blkCnt = blockSize >> 2U;
68
69 while (blkCnt > 0U)
70 {
71 /* C = (float64_t) A / 128 */
72
73 /* Convert from q7 to float and store result in destination buffer */
74 *pDst++ = ((float64_t) * pIn++ / 128.0);
75 *pDst++ = ((float64_t) * pIn++ / 128.0);
76 *pDst++ = ((float64_t) * pIn++ / 128.0);
77 *pDst++ = ((float64_t) * pIn++ / 128.0);
78
79 /* Decrement loop counter */
80 blkCnt--;
81 }
82
83 /* Loop unrolling: Compute remaining outputs */
84 blkCnt = blockSize % 0x4U;
85
86 #else
87
88 /* Initialize blkCnt with number of samples */
89 blkCnt = blockSize;
90
91 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
92
93 while (blkCnt > 0U)
94 {
95 /* C = (float64_t) A / 128 */
96
97 /* Convert from q7 to float and store result in destination buffer */
98 *pDst++ = ((float64_t) * pIn++ / 128.0);
99
100 /* Decrement loop counter */
101 blkCnt--;
102 }
103
104 }
105
106
107 /**
108 @} end of q7_to_x group
109 */
110
111