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# arm_cmplx_mult_real_q15.c

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    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
    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

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