1 /*-----------------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
8 * Title: arm_fir_interpolate_init_q31.c
10 * Description: Q31 FIR interpolator initialization function
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Version 1.0.10 2011/7/15
15 * Big Endian support added and Merged M0 and M3/M4 Source code.
17 * Version 1.0.3 2010/11/29
18 * Re-organized the CMSIS folders and updated documentation.
20 * Version 1.0.2 2010/11/11
21 * Documentation updated.
23 * Version 1.0.1 2010/10/05
24 * Production release and review comments incorporated.
26 * Version 1.0.0 2010/09/20
27 * Production release and review comments incorporated
29 * Version 0.0.7 2010/06/10
30 * Misra-C changes done
31 * ---------------------------------------------------------------------------*/
36 * @ingroup groupFilters
40 * @addtogroup FIR_Interpolate
46 * @brief Initialization function for the Q31 FIR interpolator.
47 * @param[in,out] *S points to an instance of the Q31 FIR interpolator structure.
48 * @param[in] L upsample factor.
49 * @param[in] numTaps number of filter coefficients in the filter.
50 * @param[in] *pCoeffs points to the filter coefficient buffer.
51 * @param[in] *pState points to the state buffer.
52 * @param[in] blockSize number of input samples to process per call.
53 * @return The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if
54 * the filter length <code>numTaps</code> is not a multiple of the interpolation factor <code>L</code>.
58 * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
60 * {b[numTaps-1], b[numTaps-2], b[numTaps-2], ..., b[1], b[0]}
62 * The length of the filter <code>numTaps</code> must be a multiple of the interpolation factor <code>L</code>.
64 * <code>pState</code> points to the array of state variables.
65 * <code>pState</code> is of length <code>(numTaps/L)+blockSize-1</code> words
66 * where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_interpolate_q31()</code>.
69 arm_status arm_fir_interpolate_init_q31(
70 arm_fir_interpolate_instance_q31 * S,
79 /* The filter length must be a multiple of the interpolation factor */
80 if((numTaps % L) != 0u)
82 /* Set status as ARM_MATH_LENGTH_ERROR */
83 status = ARM_MATH_LENGTH_ERROR;
88 /* Assign coefficient pointer */
91 /* Assign Interpolation factor */
94 /* Assign polyPhaseLength */
95 S->phaseLength = numTaps / L;
97 /* Clear state buffer and size of buffer is always phaseLength + blockSize - 1 */
99 (blockSize + ((uint32_t) S->phaseLength - 1u)) * sizeof(q31_t));
101 /* Assign state pointer */
104 status = ARM_MATH_SUCCESS;
112 * @} end of FIR_Interpolate group