Diff: src/Cortex-M4-M3/FilteringFunctions/arm_fir_decimate_init_f32.c

Revision:

0:1014af42efd9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Cortex-M4-M3/FilteringFunctions/arm_fir_decimate_init_f32.c	Thu Mar 10 15:07:50 2011 +0000
@@ -0,0 +1,106 @@
+/*-----------------------------------------------------------------------------  
+* Copyright (C) 2010 ARM Limited. All rights reserved.  
+*  
+* $Date:        29. November 2010  
+* $Revision: 	V1.0.3  
+*  
+* Project: 	    CMSIS DSP Library  
+* Title:        arm_fir_decimate_init_f32.c  
+*  
+* Description:  Floating-point FIR Decimator initialization function.  
+*  
+* Target Processor: Cortex-M4/Cortex-M3
+*  
+* Version 1.0.3 2010/11/29 
+*    Re-organized the CMSIS folders and updated documentation.  
+*   
+* Version 1.0.2 2010/11/11  
+*    Documentation updated.   
+*  
+* Version 1.0.1 2010/10/05   
+*    Production release and review comments incorporated.  
+*  
+* Version 1.0.0 2010/09/20   
+*    Production release and review comments incorporated  
+*  
+* Version 0.0.7  2010/06/10   
+*    Misra-C changes done  
+* ---------------------------------------------------------------------------*/ 
+ 
+#include "arm_math.h" 
+ 
+/**  
+ * @ingroup groupFilters  
+ */ 
+ 
+/**  
+ * @addtogroup FIR_decimate  
+ * @{  
+ */ 
+ 
+/**  
+ * @brief  Initialization function for the floating-point FIR decimator.  
+ * @param[in,out] *S points to an instance of the floating-point FIR decimator structure.  
+ * @param[in] numTaps  number of coefficients in the filter.  
+ * @param[in] M  decimation factor.  
+ * @param[in] *pCoeffs points to the filter coefficients.  
+ * @param[in] *pState points to the state buffer.  
+ * @param[in] blockSize number of input samples to process per call.  
+ * @return    The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if  
+ * <code>blockSize</code> is not a multiple of <code>M</code>.  
+ *  
+ * <b>Description:</b>  
+ * \par  
+ * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:  
+ * <pre>  
+ *    {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}  
+ * </pre>  
+ * \par  
+ * <code>pState</code> points to the array of state variables.  
+ * <code>pState</code> is of length <code>numTaps+blockSize-1</code> words where <code>blockSize</code> is the number of input samples passed to <code>arm_fir_decimate_f32()</code>.  
+ * <code>M</code> is the decimation factor.  
+ */ 
+ 
+arm_status arm_fir_decimate_init_f32( 
+  arm_fir_decimate_instance_f32 * S, 
+  uint16_t numTaps, 
+  uint8_t M, 
+  float32_t * pCoeffs, 
+  float32_t * pState, 
+  uint32_t blockSize) 
+{ 
+  arm_status status; 
+ 
+  /* The size of the input block must be a multiple of the decimation factor */ 
+  if((blockSize % M) != 0u) 
+  { 
+    /* Set status as ARM_MATH_LENGTH_ERROR */ 
+    status = ARM_MATH_LENGTH_ERROR; 
+  } 
+  else 
+  { 
+    /* Assign filter taps */ 
+    S->numTaps = numTaps; 
+ 
+    /* Assign coefficient pointer */ 
+    S->pCoeffs = pCoeffs; 
+ 
+    /* Clear state buffer and size is always (blockSize + numTaps - 1) */ 
+    memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(float32_t)); 
+ 
+    /* Assign state pointer */ 
+    S->pState = pState; 
+ 
+    /* Assign Decimation Factor */ 
+    S->M = M; 
+ 
+    status = ARM_MATH_SUCCESS; 
+  } 
+ 
+  return (status); 
+ 
+} 
+ 
+/**  
+ * @} end of FIR_decimate group  
+ */