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_fir_decimate_init_q15.c 00009 * 00010 * Description: Initialization function for the Q15 FIR Decimator. 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 * Version 0.0.7 2010/06/10 00027 * Misra-C changes done 00028 * ------------------------------------------------------------------- */ 00029 00030 #include "arm_math.h" 00031 00065 arm_status arm_fir_decimate_init_q15( 00066 arm_fir_decimate_instance_q15 * S, 00067 uint16_t numTaps, 00068 uint8_t M, 00069 q15_t * pCoeffs, 00070 q15_t * pState, 00071 uint32_t blockSize) 00072 { 00073 00074 arm_status status; 00075 00076 /* The size of the input block must be a multiple of the decimation factor */ 00077 if((blockSize % M) != 0u) 00078 { 00079 /* Set status as ARM_MATH_LENGTH_ERROR */ 00080 status = ARM_MATH_LENGTH_ERROR; 00081 } 00082 else 00083 { 00084 /* Assign filter taps */ 00085 S->numTaps = numTaps; 00086 00087 /* Assign coefficient pointer */ 00088 S->pCoeffs = pCoeffs; 00089 00090 /* Clear the state buffer. The size of buffer is always (blockSize + numTaps - 1) */ 00091 memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(q15_t)); 00092 00093 /* Assign state pointer */ 00094 S->pState = pState; 00095 00096 /* Assign Decimation factor */ 00097 S->M = M; 00098 00099 status = ARM_MATH_SUCCESS; 00100 } 00101 00102 return (status); 00103 00104 } 00105