Diff: cmsis_dsp/FilteringFunctions/arm_biquad_cascade_stereo_df2T_init_f32.c

Revision:

5:3762170b6d4d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/FilteringFunctions/arm_biquad_cascade_stereo_df2T_init_f32.c	Fri Nov 20 08:45:18 2015 +0000
@@ -0,0 +1,102 @@
+/*-----------------------------------------------------------------------------    
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
+*    
+* $Date:        19. March 2015
+* $Revision: 	V.1.4.5
+*    
+* Project: 	    CMSIS DSP Library    
+* Title:        arm_biquad_cascade_stereo_df2T_init_f32.c    
+*    
+* Description:  Initialization function for the floating-point transposed   
+*               direct form II Biquad cascade filter.   
+*    
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*  
+* Redistribution and use in source and binary forms, with or without 
+* modification, are permitted provided that the following conditions
+* are met:
+*   - Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*   - Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in
+*     the documentation and/or other materials provided with the 
+*     distribution.
+*   - Neither the name of ARM LIMITED nor the names of its contributors
+*     may be used to endorse or promote products derived from this
+*     software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.   
+* ---------------------------------------------------------------------------*/
+
+#include "arm_math.h"
+
+/**    
+ * @ingroup groupFilters    
+ */
+
+/**    
+ * @addtogroup BiquadCascadeDF2T    
+ * @{    
+ */
+
+/**   
+ * @brief  Initialization function for the floating-point transposed direct form II Biquad cascade filter.   
+ * @param[in,out] *S           points to an instance of the filter data structure.   
+ * @param[in]     numStages    number of 2nd order stages in the filter.   
+ * @param[in]     *pCoeffs     points to the filter coefficients.   
+ * @param[in]     *pState      points to the state buffer.   
+ * @return        none   
+ *    
+ * <b>Coefficient and State Ordering:</b>    
+ * \par    
+ * The coefficients are stored in the array <code>pCoeffs</code> in the following order:    
+ * <pre>    
+ *     {b10, b11, b12, a11, a12, b20, b21, b22, a21, a22, ...}    
+ * </pre>    
+ *    
+ * \par    
+ * where <code>b1x</code> and <code>a1x</code> are the coefficients for the first stage,    
+ * <code>b2x</code> and <code>a2x</code> are the coefficients for the second stage,    
+ * and so on.  The <code>pCoeffs</code> array contains a total of <code>5*numStages</code> values.    
+ *    
+ * \par    
+ * The <code>pState</code> is a pointer to state array.    
+ * Each Biquad stage has 2 state variables <code>d1,</code> and <code>d2</code> for each channel.    
+ * The 2 state variables for stage 1 are first, then the 2 state variables for stage 2, and so on.    
+ * The state array has a total length of <code>2*numStages</code> values.    
+ * The state variables are updated after each block of data is processed; the coefficients are untouched.    
+ */
+
+void arm_biquad_cascade_stereo_df2T_init_f32(
+  arm_biquad_cascade_stereo_df2T_instance_f32 * S,
+  uint8_t numStages,
+  float32_t * pCoeffs,
+  float32_t * pState)
+{
+  /* Assign filter stages */
+  S->numStages = numStages;
+
+  /* Assign coefficient pointer */
+  S->pCoeffs = pCoeffs;
+
+  /* Clear state buffer and size is always 4 * numStages */
+  memset(pState, 0, (4u * (uint32_t) numStages) * sizeof(float32_t));
+
+  /* Assign state pointer */
+  S->pState = pState;
+}
+
+/**    
+ * @} end of BiquadCascadeDF2T group    
+ */