dds_hls.cpp

/*
 * Copyright (c) 2023, KUHEP, Kyoto University
 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
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 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 2. 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.
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 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
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 * 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.
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 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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#include "dds_hls.hpp"

const ph phase_offset_q = (1 << (BW_PHASE - 2));
const ph phase_offset_i = 0;

data calc_i(ph phase){
    #pragma HLS inline recursive
    ph_f phase_pi;
    // Bitwize interpretation
    phase_pi(BW_PHASE-1, 0) = phase(BW_PHASE-1, 0);

    return hls::cospi(phase_pi);
}

void calc(ph pinc,
          ph phase,
          ph stage,
          data& data_out)
{
    #pragma HLS PIPELINE II=1
    data tmp = calc_i(phase + pinc*stage);

    data_out = tmp;
}

void push(data buffer[N_CH], hls::stream<data_tot>& out){
    #pragma HLS PIPELINE II=1
    data_tot tmp;
    for(int i = 0; i < N_CH; i++){
        tmp(BW_DATA*(i+1)-1, BW_DATA*i) = buffer[i](BW_DATA-1,0);
    }
    out.write(tmp);
}

void phase_calc(ph pinc,
                ph& phase_i,
                ph& phase_q){
    #pragma HLS PIPELINE II=1
    static ph phase_now = 0;

    phase_i = phase_now + phase_offset_i;
    phase_q = phase_now + phase_offset_q;
    phase_now += pinc*N_CH;
}

void dds_hls(ph pinc,
             hls::stream<data_tot>& data_i,
             hls::stream<data_tot>& data_q){
// Input
#pragma HLS INTERFACE mode=s_axilite port=pinc clock=s_axi_aclk
// Output
#pragma HLS INTERFACE axis register port=data_i name=m_axis_data_i
#pragma HLS INTERFACE axis register port=data_q name=m_axis_data_q

// Ctrl interface suppression.
#pragma HLS INTERFACE ap_ctrl_none port=return
#pragma HLS DATAFLOW
#pragma HLS stable variable=pinc
    
    //static hls::stream<ph,100> phase_int;
    static ph phase_tmp_i, phase_tmp_q;
    static data i_buffer[N_CH];
    static data q_buffer[N_CH];

    phase_calc(pinc, phase_tmp_i, phase_tmp_q);

    calc_loop: for(int i = 0; i < N_CH; i++){
        #pragma HLS unroll
        calc(pinc, phase_tmp_i, i, i_buffer[i]);
        calc(pinc, phase_tmp_q, i, q_buffer[i]);
    }
    push(i_buffer, data_i);
    push(q_buffer, data_q);
}