Polyphase_filter_vhdl/poly_fir_blk.vhd

LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
USE work.POLY_FIR_PKG.ALL;



ENTITY poly_fir_blk IS

  PORT (
    i_clk    : IN  std_logic;
    i_coeffs : IN  vect_polyfir_coeffs_in;
    i_data   : IN  vect_adc_data_out;
    o_data   : OUT matrix_fir_data_out);

END ENTITY poly_fir_blk;

ARCHITECTURE polyphase OF poly_fir_blk IS

  SIGNAL matrix3D_reg_out_simple_rif_in : matrix3D_reg_data_out := (OTHERS => (OTHERS => (OTHERS => (OTHERS => '0'))));
  SIGNAL matrix_coeffs                  : matrix_fir_coeffs_in  := (OTHERS => (OTHERS => (OTHERS => '0')));
  SIGNAL matrix_fir_out                 : matrix_fir_data_out   := (OTHERS => (OTHERS => (OTHERS => '0')));


BEGIN  -- ARCHITECTURE polyphase



  --purpose: fill the polyphase coefficients into a 2D matrix from the filter vector (1D)
  fill_coeff : PROCESS(i_coeffs)        -- rearrange coeffs into a matrix
    VARIABLE coeff_nb     : natural;
    VARIABLE sf_coeff     : natural;
    VARIABLE subfilter_nb : natural;
  BEGIN
    coeff_nb     := 0;
    sf_coeff     := 0;
    subfilter_nb := 0;
    coeff_for_matrix : FOR coeff_nb IN 0 TO cst_nb_coeffs_filter_in-1 LOOP
      matrix_coeffs(subfilter_nb)(sf_coeff) <= i_coeffs(coeff_nb);
      subfilter_nb                          := subfilter_nb+1;
      IF (subfilter_nb = cst_nb_subfilters) THEN
        sf_coeff     := sf_coeff+1;
        subfilter_nb := 0;
      END IF;
    END LOOP coeff_for_matrix;
  END PROCESS fill_coeff;



  -- instanciation of the shift-reg for polyphasd filter
  shift_reg_inst : ENTITY work.POLY_SHIFT_REG(Fill_Matrix)
    PORT MAP (i_clk  => i_clk,
              i_data => i_data,
              o_data => matrix3D_reg_out_simple_rif_in
              );



  -- instanciation of the cst_nb_subfilters subfilters
  simple_fir_inst_loop : FOR i IN 0 TO cst_nb_subfilters-1 GENERATE
    simple_fir_inst : ENTITY work.TREE_FIR(Simple_Fir)
      PORT MAP(i_clk    => i_clk,
               i_coeffs => matrix_coeffs(i),
               i_data   => matrix3D_reg_out_simple_rif_in(i),
               o_data   => matrix_fir_out(i)
               );
  END GENERATE simple_fir_inst_loop;




  o_data <= matrix_fir_out;

END ARCHITECTURE polyphase;