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Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_init_q31.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_init_q31.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_init_q31.c b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_init_q31.c new file mode 100644 index 000000000..dbbb8aa2b --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_biquad_cascade_df1_init_q31.c @@ -0,0 +1,109 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_biquad_cascade_df1_init_q31.c
+*
+* Description: Q31 Biquad cascade DirectFormI(DF1) filter initialization function.
+*
+*
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*
+* Version 1.1.0 2012/02/15
+* Updated with more optimizations, bug fixes and minor API changes.
+*
+* Version 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* 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 0.0.5 2010/04/26
+* incorporated review comments and updated with latest CMSIS layer
+*
+* Version 0.0.3 2010/03/10
+* Initial version
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupFilters
+ */
+
+/**
+ * @addtogroup BiquadCascadeDF1
+ * @{
+ */
+
+/**
+ * @details
+ *
+ * @param[in,out] *S points to an instance of the Q31 Biquad cascade structure.
+ * @param[in] numStages number of 2nd order stages in the filter.
+ * @param[in] *pCoeffs points to the filter coefficients buffer.
+ * @param[in] *pState points to the state buffer.
+ * @param[in] postShift Shift to be applied after the accumulator. Varies according to the coefficients format
+ * @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>
+ * 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> points to state variables array.
+ * Each Biquad stage has 4 state variables <code>x[n-1], x[n-2], y[n-1],</code> and <code>y[n-2]</code>.
+ * The state variables are arranged in the <code>pState</code> array as:
+ * <pre>
+ * {x[n-1], x[n-2], y[n-1], y[n-2]}
+ * </pre>
+ * The 4 state variables for stage 1 are first, then the 4 state variables for stage 2, and so on.
+ * The state array has a total length of <code>4*numStages</code> values.
+ * The state variables are updated after each block of data is processed; the coefficients are untouched.
+ */
+
+void arm_biquad_cascade_df1_init_q31(
+ arm_biquad_casd_df1_inst_q31 * S,
+ uint8_t numStages,
+ q31_t * pCoeffs,
+ q31_t * pState,
+ int8_t postShift)
+{
+ /* Assign filter stages */
+ S->numStages = numStages;
+
+ /* Assign postShift to be applied to the output */
+ S->postShift = postShift;
+
+ /* Assign coefficient pointer */
+ S->pCoeffs = pCoeffs;
+
+ /* Clear state buffer and size is always 4 * numStages */
+ memset(pState, 0, (4u * (uint32_t) numStages) * sizeof(q31_t));
+
+ /* Assign state pointer */
+ S->pState = pState;
+}
+
+/**
+ * @} end of BiquadCascadeDF1 group
+ */
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