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-- Company: 
-- Engineer: 
-- 
-- Create Date:    16:20:51 03/03/2010 
-- Design Name: 
-- Module Name:    pw_checker - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity pw_checker is
	generic( lower_pw : natural := 2;
				upper_pw : natural := 4);
    Port ( input : in  STD_LOGIC;
			  rst : in STD_LOGIC;
			  clk : in  STD_LOGIC;
           output : out  STD_LOGIC);
end pw_checker;

architecture Behavioral of pw_checker is



signal cnt : natural;
--signal pw  : natural;
--signal test : std_logic;
signal start : std_logic;

begin

count_pw: process(clk,input)
begin
	
	if( clk'event and clk = '1' ) then
		if ( start = '1' ) then
			cnt <= cnt + 1;
--			pw <= cnt+1;
		else
			cnt <= 0;
--			pw <= cnt;
		end if;
	end if;	
	
end process count_pw;


--do_out: process(input)
--begin

--	if( input'event and input = '0' ) then
			
--		if( cnt <= upper_pw and cnt >= lower_pw ) then
--			output <= '1';
--		else
--			output <= '0';
--		end if;	
--	else
	--	if(input'event and input = '1') then
	--		start <= '1';
--		end if;	
--	end if;
	

--end process;

do_out: process(input)
begin
	if(input'event and input = '0' ) then 
		if( cnt <= upper_pw and cnt >= lower_pw ) then
			output <= '1';
		else
			output <= '0';
		end if;
	end if;
end process do_out;

do_start: process(input)
begin
	if( input = '0' ) then
		start <= '0';		
	else 
		start <= '1';
	end if;

end process;



--do_out: process(input)
--begin
--	if( input'event and input = '0' ) then
--	if( clk'event and clk = '1' ) then
--		if( pw <= upper_pw and pw >= lower_pw ) then
--			output <= '1';
--		else
--			output <= '0';
--		end if;
--	end if;	
--end process do_out;

end Behavioral;