------------------------------------------------------------------------
-- fft_magnitude_calc
--
-- calculation of FFT magnitude sqrt(real_part²+im_part²)
-- Inputs:
-- input_re in: +-1 signed Fixpoint (0.5=0x40000000, -0.5=0xC0000000 (negative numbers in 2K)
-- input_im in: +-1 signed Fixpoint (0.5=0x40000000, -0.5=0xC0000000 (negative numbers in 2K)
-- input_valid: high = inputs are valid for data processing 
-- Outputs
-- output_magnitude: Fixpoint 0.5=0x40000000 (always positive)
-- output_valid:     high = magnitude data is valid
-----------------------------------------------------------------------

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity tb_fft_magnitude_calc is
    generic( GUI_MODE : boolean; CHECK_RESULTS : boolean );
end entity tb_fft_magnitude_calc;


architecture rtl of tb_fft_magnitude_calc is


    signal clk : std_logic := '0';                            -- Takt
    signal reset :  std_logic := '1';                          -- Reset
    signal input_valid:  std_logic := '0';               -- Eingangsdaten gültig
    signal input_re :  std_logic_vector( 31 downto 0 ) := X"40000000"; -- Realteil in Fixpoint
    signal input_im :  std_logic_vector( 31 downto 0 ):= X"40000000"; -- Imaginärteil in Fixpoint
    signal output_valid :  std_logic;                  -- Ausgangsdaten gültig
    signal output_magnitude :  std_logic_vector( 31 downto 0 );

begin
        
        clk <= not clk after 10 ns;

    reset_release : process is
    begin
         wait for 435 ns;
         reset <= '0';
         wait;
    end process reset_release;
    
    -- Instanziierung des SQRT Moduls für die Berechnung der Quardratwurzel
    -- Weisen Sie die Signale output_sqrt, reset, input_sqrt und clk richtig zu
    fft_magnitude_calc_module : entity work.fft_magnitude_calc
    port map (
        clk => clk,
        reset => reset,
        input_valid => input_valid,               -- Eingangsdaten gültig
        input_re => input_re, -- Realteil in Fixpoint
        input_im => input_im, -- Imaginärteil in Fixpoint
        output_valid => output_valid,                  -- Ausgangsdaten gültig
        output_magnitude => output_magnitude -- Berechnete magnitude
    );

    stimulus: process is
    begin
        wait until falling_edge( reset );
        wait until falling_edge( clk );
        input_valid <= '1';
        wait until falling_edge( clk );
        input_valid <= '0';

        wait until falling_edge( output_valid );

        wait for 200 ns;

        wait until falling_edge( clk );
        input_valid <= '1';
        input_re <= X"20000000";
        input_im <= X"20000000";
        wait until falling_edge( clk );
        input_valid <= '0';

        wait until falling_edge( output_valid );


        wait until falling_edge( clk );
        if ( GUI_MODE ) then
            std.env.stop;
        else
            std.env.finish;
        end if;
    
    end process stimulus;
 
end architecture rtl;