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
arm_cmplx_mult_real_q15.c
00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2010 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 29. November 2010 00005 * $Revision: V1.0.3 00006 * 00007 * Project: CMSIS DSP Library 00008 * Title: arm_cmplx_mult_real_q15.c 00009 * 00010 * Description: Q15 complex by real multiplication 00011 * 00012 * Target Processor: Cortex-M4/Cortex-M3 00013 * 00014 * Version 1.0.3 2010/11/29 00015 * Re-organized the CMSIS folders and updated documentation. 00016 * 00017 * Version 1.0.2 2010/11/11 00018 * Documentation updated. 00019 * 00020 * Version 1.0.1 2010/10/05 00021 * Production release and review comments incorporated. 00022 * 00023 * Version 1.0.0 2010/09/20 00024 * Production release and review comments incorporated. 00025 * -------------------------------------------------------------------- */ 00026 00027 #include "arm_math.h" 00028 00029 /** 00030 * @ingroup groupCmplxMath 00031 */ 00032 00033 /** 00034 * @addtogroup CmplxByRealMult 00035 * @{ 00036 */ 00037 00038 00039 /** 00040 * @brief Q15 complex-by-real multiplication 00041 * @param[in] *pSrcCmplx points to the complex input vector 00042 * @param[in] *pSrcReal points to the real input vector 00043 * @param[out] *pCmplxDst points to the complex output vector 00044 * @param[in] numSamples number of samples in each vector 00045 * @return none. 00046 * 00047 * <b>Scaling and Overflow Behavior:</b> 00048 * \par 00049 * The function uses saturating arithmetic. 00050 * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated. 00051 */ 00052 00053 void arm_cmplx_mult_real_q15( 00054 q15_t * pSrcCmplx, 00055 q15_t * pSrcReal, 00056 q15_t * pCmplxDst, 00057 uint32_t numSamples) 00058 { 00059 q15_t in; /* Temporary variable to store input value */ 00060 uint32_t blkCnt; /* loop counters */ 00061 00062 /* loop Unrolling */ 00063 blkCnt = numSamples >> 2u; 00064 00065 /* First part of the processing with loop unrolling. Compute 4 outputs at a time. 00066 ** a second loop below computes the remaining 1 to 3 samples. */ 00067 while(blkCnt > 0u) 00068 { 00069 /* C[2 * i] = A[2 * i] * B[i]. */ 00070 /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */ 00071 in = *pSrcReal++; 00072 /* store the result in the destination buffer. */ 00073 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00074 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00075 00076 in = *pSrcReal++; 00077 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00078 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00079 00080 in = *pSrcReal++; 00081 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00082 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00083 00084 in = *pSrcReal++; 00085 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00086 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00087 00088 /* Decrement the numSamples loop counter */ 00089 blkCnt--; 00090 } 00091 00092 /* If the numSamples is not a multiple of 4, compute any remaining output samples here. 00093 ** No loop unrolling is used. */ 00094 blkCnt = numSamples % 0x4u; 00095 00096 while(blkCnt > 0u) 00097 { 00098 /* C[2 * i] = A[2 * i] * B[i]. */ 00099 /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */ 00100 in = *pSrcReal++; 00101 /* store the result in the destination buffer. */ 00102 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00103 *pCmplxDst++ = (q15_t) __SSAT((((q31_t) (*pSrcCmplx++) * (in)) >> 15), 16); 00104 00105 /* Decrement the numSamples loop counter */ 00106 blkCnt--; 00107 } 00108 } 00109 00110 /** 00111 * @} end of CmplxByRealMult group 00112 */
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