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Functions

Name
void plp_cfft_q16(const plp_cfft_instance_q16 * S, int16_t * p1, uint8_t ifftFlag, uint8_t bitReverseFlag, uint32_t deciPoint)
Glue code for quantized 16 bit complex fast fourier transform.

Functions Documentation

function plp_cfft_q16

void plp_cfft_q16(
    const plp_cfft_instance_q16 * S,
    int16_t * p1,
    uint8_t ifftFlag,
    uint8_t bitReverseFlag,
    uint32_t deciPoint
)

Glue code for quantized 16 bit complex fast fourier transform.

Parameters:

  • S points to an instance of the 16bit quantized CFFT structure
  • p1 points to the complex data buffer of size 2*fftLen. Processing occurs in-place.
  • ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
  • bitReverseFlag flag that enables (bitReverseFlag=1) of disables (bitReverseFlag=0) bit reversal of output.
  • deciPoint decimal point for right shift

Source code

/* =====================================================================
 * Project:      PULP DSP Library
 * Title:        plp_cfft_q16.c
 * Description:  16-bit fixed point Fast Fourier Transform on Complex Input Data
 *
 * $Date:        27. June 2020
 * $Revision:    V0
 *
 * Target Processor: PULP cores
 * ===================================================================== */
/*
 * Copyright (C) 2020 ETH Zurich and University of Bologna. All rights reserved.
 *
 * Author: Michael Rogenmoser, ETH Zurich
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "plp_math.h"

void plp_cfft_q16(const plp_cfft_instance_q16 *S,
                  int16_t *p1,
                  uint8_t ifftFlag,
                  uint8_t bitReverseFlag,
                  uint32_t deciPoint) {

    // if (deciPoint != 15) {
    //     printf("Only Q1.15 fixed point supported currently.\n");
    //     return;
    // }

    if (hal_cluster_id() == ARCHI_FC_CID) {
        plp_cfft_q16s_rv32im(S, p1, ifftFlag, bitReverseFlag, deciPoint);
    } else {
        plp_cfft_q16s_xpulpv2(S, p1, ifftFlag, bitReverseFlag, deciPoint);
    }
}

Updated on 2023-03-01 at 16:16:33 +0000