library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

package filter_pkg is
	constant MAX_RANGE : integer := 511;
	
    type array_of_integers is array(integer range <>) of integer range -MAX_RANGE to MAX_RANGE;
    
    function array_sum ( K : in  array_of_integers ) 
				return integer;
    function reorder_array ( K : in  array_of_integers ; simetric : in boolean ) 
				return array_of_integers;
				
				
	component Filter is

		generic (
			CLK_FREQ : integer  := 200e6;
			DATA_RATE: integer  := 250e3;


			SIMETRIC : boolean := TRUE;
			CONSTANTS : array_of_integers := (-4,-3,-2,-1,0,1,2,3,4,5)
			
		);
		port (
			clk_i : in std_logic;
			enable: in std_logic;
			reset:  in std_logic;
			
			d_i  : in std_logic;
			d_o  : out std_logic;
			p_o  : out std_logic_vector(9 downto 0)
		);
	end component;
	
end package;

package body filter_pkg is

	function array_sum ( K : in array_of_integers ) return integer is
		variable sum : integer := 0;
	begin
		for i in 0 to K'length-1 loop
			sum := sum + K(K'left + i);		
		end loop;
		
		return sum;
	end array_sum;
	
	
	function reorder_array ( K : in  array_of_integers ; simetric : in boolean ) 
					return array_of_integers is
		constant M : integer := 1 + 2*((K'length)-1);
		constant N : integer := K'length;
		variable arr_s : array_of_integers( 0 to M-1 );
		variable arr_a : array_of_integers( 0 to N-1  );
	
	begin
		if ( simetric ) then 
			for i in 0 to N-1 loop
				arr_s( i ) := K( K'left + i );
			end loop;
			
			for i in 1 to N-1 loop
				arr_s( n + i - 1 ) := K( K'right - i );
			end loop;
			return arr_s;
		else
			for i in 0 to N-1 loop
				arr_a( i ) := K( K'left + i );
			end loop;
			return arr_a;
		end if;
	end reorder_array;

end filter_pkg;