-- recursive averaging

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

entity reg1 is
 port
 (
	clk 				: in std_logic;
	reset				: in std_logic;
	start_en			: in std_logic;	
	data_in			: in std_logic_vector(11 downto 0); --current sample in from SINC filter
	u_h				: in std_logic;
	v_h				: in std_logic;
	w_h				: in std_logic;
	avg_out		: out signed (18 downto 0)
 );
end reg1;


architecture RTL of reg1 is
signal current_avg_old			:signed (18 downto 0);
signal time_avg_old				:signed (15 downto 0);
signal time_sqr_avg_old			:signed (31 downto 0);
signal current_time_avg_old 	:signed (34 downto 0);


begin
 process(data_in)
	
	variable diff						:signed(18 downto 0);
	variable current_avg				:signed(18 downto 0);
	variable scaled_current			:signed(18 downto 0);
	variable count 					:integer range 0 to 53;--signed(8 downto 0);
	variable resize_current			:signed(18 downto 0);
	
	begin
		if ( reset='0' ) then
			current_avg_old	<=(others =>'0');
			diff					:=(others =>'0');
			current_avg			:=(others =>'0');
			scaled_current		:=(others =>'0');
			count					:=0;--(others =>'0');
--			state					<= 0;
		elsif (rising_edge(clk)) then
			if (start_en='1') then  --PWM Block up_down_out
				if (not(u_h='1' and v_h='1' and w_h='1') or (u_h='0' and v_h='0' and w_h='0')) then -- start regression
					count			:=count+1;
					resize_current:= resize(signed(data_in),19);
					scaled_current:= resize_current sll 7;
					diff := signed(scaled_current(18 downto 0)) - signed(current_avg_old(18 downto 0));				
					current_avg:= current_avg_old + (diff/count);
					current_avg_old<=current_avg;
				else
					count :=0;					
				end if;
				avg_out<=current_avg;
			end if;	
		end if;
	end process;
end RTL;