Subversion Repositories graphicsaccelerator

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.numeric_std.all;

use IEEE.std_logic_unsigned.all;

entity Debouncer is

    Port ( Clk : in  STD_LOGIC;

           Button : in  STD_LOGIC;

                          Dout : out  STD_LOGIC);

end Debouncer;

architecture Behavioral of Debouncer is

signal Counter,nCounter : STD_LOGIC_VECTOR (23 downto 0) := x"000000";

signal ButtonHistory,nButtonHistory : STD_LOGIC_VECTOR (1 downto 0) := "00";

signal nextHistory : STD_LOGIC := '0';

begin

nCounter <= x"FFFFFF" when Counter=x"FFFFFF" and Button='1' else

                                x"000000" when Counter=x"000000" and Button='0' else

                                Counter+1 when Button='1' else Counter-1;

nextHistory <= '0' when Counter=x"000000" else '1';

nButtonHistory <= nextHistory & ButtonHistory(1);

Dout <= '1' when ButtonHistory="01" else '0';

process (Clk) begin

        if (rising_edge(Clk)) then

                Counter <= nCounter;

                ButtonHistory <= nButtonHistory;

        end if;

end process;

end Behavioral;