Simon Ford
CMSIS DSP Library from CMSIS 2.0. See http://www.onarm.com/cmsis/ for full details
Dependents: K22F_DSP_Matrix_least_square BNO055-ELEC3810 1BNO055 ECE4180Project--Slave2 ... more
src/Cortex-M4-M3/SupportFunctions/arm_q7_to_q31.c@0:1014af42efd9, 2011-03-10 (annotated)
- Committer:
- simon
- Date:
- Thu Mar 10 15:07:50 2011 +0000
- Revision:
- 0:1014af42efd9
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| simon | 0:1014af42efd9 | 1 | /* ---------------------------------------------------------------------------- |
| simon | 0:1014af42efd9 | 2 | * Copyright (C) 2010 ARM Limited. All rights reserved. |
| simon | 0:1014af42efd9 | 3 | * |
| simon | 0:1014af42efd9 | 4 | * $Date: 29. November 2010 |
| simon | 0:1014af42efd9 | 5 | * $Revision: V1.0.3 |
| simon | 0:1014af42efd9 | 6 | * |
| simon | 0:1014af42efd9 | 7 | * Project: CMSIS DSP Library |
| simon | 0:1014af42efd9 | 8 | * Title: arm_q7_to_q31.c |
| simon | 0:1014af42efd9 | 9 | * |
| simon | 0:1014af42efd9 | 10 | * Description: Processing function for the Conversion from Q7 to Q31 |
| simon | 0:1014af42efd9 | 11 | * |
| simon | 0:1014af42efd9 | 12 | * Target Processor: Cortex-M4/Cortex-M3 |
| simon | 0:1014af42efd9 | 13 | * |
| simon | 0:1014af42efd9 | 14 | * Version 1.0.3 2010/11/29 |
| simon | 0:1014af42efd9 | 15 | * Re-organized the CMSIS folders and updated documentation. |
| simon | 0:1014af42efd9 | 16 | * |
| simon | 0:1014af42efd9 | 17 | * Version 1.0.2 2010/11/11 |
| simon | 0:1014af42efd9 | 18 | * Documentation updated. |
| simon | 0:1014af42efd9 | 19 | * |
| simon | 0:1014af42efd9 | 20 | * Version 1.0.1 2010/10/05 |
| simon | 0:1014af42efd9 | 21 | * Production release and review comments incorporated. |
| simon | 0:1014af42efd9 | 22 | * |
| simon | 0:1014af42efd9 | 23 | * Version 1.0.0 2010/09/20 |
| simon | 0:1014af42efd9 | 24 | * Production release and review comments incorporated. |
| simon | 0:1014af42efd9 | 25 | * ---------------------------------------------------------------------------- */ |
| simon | 0:1014af42efd9 | 26 | |
| simon | 0:1014af42efd9 | 27 | #include "arm_math.h" |
| simon | 0:1014af42efd9 | 28 | |
| simon | 0:1014af42efd9 | 29 | /** |
| simon | 0:1014af42efd9 | 30 | * @ingroup groupSupport |
| simon | 0:1014af42efd9 | 31 | */ |
| simon | 0:1014af42efd9 | 32 | |
| simon | 0:1014af42efd9 | 33 | /** |
| simon | 0:1014af42efd9 | 34 | * @addtogroup q7_to_x |
| simon | 0:1014af42efd9 | 35 | * @{ |
| simon | 0:1014af42efd9 | 36 | */ |
| simon | 0:1014af42efd9 | 37 | |
| simon | 0:1014af42efd9 | 38 | /** |
| simon | 0:1014af42efd9 | 39 | * @brief Converts the elements of the Q7 vector to Q31 vector. |
| simon | 0:1014af42efd9 | 40 | * @param[in] *pSrc points to the Q7 input vector |
| simon | 0:1014af42efd9 | 41 | * @param[out] *pDst points to the Q31 output vector |
| simon | 0:1014af42efd9 | 42 | * @param[in] blockSize length of the input vector |
| simon | 0:1014af42efd9 | 43 | * @return none. |
| simon | 0:1014af42efd9 | 44 | * |
| simon | 0:1014af42efd9 | 45 | * \par Description: |
| simon | 0:1014af42efd9 | 46 | * |
| simon | 0:1014af42efd9 | 47 | * The equation used for the conversion process is: |
| simon | 0:1014af42efd9 | 48 | * |
| simon | 0:1014af42efd9 | 49 | * <pre> |
| simon | 0:1014af42efd9 | 50 | * pDst[n] = (q31_t) pSrc[n] << 24; 0 <= n < blockSize. |
| simon | 0:1014af42efd9 | 51 | * </pre> |
| simon | 0:1014af42efd9 | 52 | * |
| simon | 0:1014af42efd9 | 53 | */ |
| simon | 0:1014af42efd9 | 54 | |
| simon | 0:1014af42efd9 | 55 | |
| simon | 0:1014af42efd9 | 56 | void arm_q7_to_q31( |
| simon | 0:1014af42efd9 | 57 | q7_t * pSrc, |
| simon | 0:1014af42efd9 | 58 | q31_t * pDst, |
| simon | 0:1014af42efd9 | 59 | uint32_t blockSize) |
| simon | 0:1014af42efd9 | 60 | { |
| simon | 0:1014af42efd9 | 61 | q7_t *pIn = pSrc; /* Src pointer */ |
| simon | 0:1014af42efd9 | 62 | uint32_t blkCnt; /* loop counter */ |
| simon | 0:1014af42efd9 | 63 | |
| simon | 0:1014af42efd9 | 64 | /*loop Unrolling */ |
| simon | 0:1014af42efd9 | 65 | blkCnt = blockSize >> 2u; |
| simon | 0:1014af42efd9 | 66 | |
| simon | 0:1014af42efd9 | 67 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
| simon | 0:1014af42efd9 | 68 | ** a second loop below computes the remaining 1 to 3 samples. */ |
| simon | 0:1014af42efd9 | 69 | while(blkCnt > 0u) |
| simon | 0:1014af42efd9 | 70 | { |
| simon | 0:1014af42efd9 | 71 | /* C = (q31_t) A << 24 */ |
| simon | 0:1014af42efd9 | 72 | /* convert from q7 to q31 and then store the results in the destination buffer */ |
| simon | 0:1014af42efd9 | 73 | *pDst++ = (q31_t) * pIn++ << 24; |
| simon | 0:1014af42efd9 | 74 | *pDst++ = (q31_t) * pIn++ << 24; |
| simon | 0:1014af42efd9 | 75 | *pDst++ = (q31_t) * pIn++ << 24; |
| simon | 0:1014af42efd9 | 76 | *pDst++ = (q31_t) * pIn++ << 24; |
| simon | 0:1014af42efd9 | 77 | |
| simon | 0:1014af42efd9 | 78 | /* Decrement the loop counter */ |
| simon | 0:1014af42efd9 | 79 | blkCnt--; |
| simon | 0:1014af42efd9 | 80 | } |
| simon | 0:1014af42efd9 | 81 | |
| simon | 0:1014af42efd9 | 82 | /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
| simon | 0:1014af42efd9 | 83 | ** No loop unrolling is used. */ |
| simon | 0:1014af42efd9 | 84 | blkCnt = blockSize % 0x4u; |
| simon | 0:1014af42efd9 | 85 | |
| simon | 0:1014af42efd9 | 86 | while(blkCnt > 0u) |
| simon | 0:1014af42efd9 | 87 | { |
| simon | 0:1014af42efd9 | 88 | /* C = (q31_t) A << 24 */ |
| simon | 0:1014af42efd9 | 89 | /* convert from q7 to q31 and then store the results in the destination buffer */ |
| simon | 0:1014af42efd9 | 90 | *pDst++ = (q31_t) * pIn++ << 24; |
| simon | 0:1014af42efd9 | 91 | |
| simon | 0:1014af42efd9 | 92 | /* Decrement the loop counter */ |
| simon | 0:1014af42efd9 | 93 | blkCnt--; |
| simon | 0:1014af42efd9 | 94 | } |
| simon | 0:1014af42efd9 | 95 | |
| simon | 0:1014af42efd9 | 96 | } |
| simon | 0:1014af42efd9 | 97 | |
| simon | 0:1014af42efd9 | 98 | /** |
| simon | 0:1014af42efd9 | 99 | * @} end of q7_to_x group |
| simon | 0:1014af42efd9 | 100 | */ |