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library IEEE;
use IEEE.STD_LOGIC_1164.all;
entity synchronizer is
generic (stages : natural := 2);
port (clk : in std_logic;
i : in std_logic;
o : out std_logic);
end synchronizer;
architecture Behavioral of synchronizer is
signal flipflops : std_logic_vector(stages-1 downto 0) := (others => '0');
attribute ASYNC_REG : string;
attribute ASYNC_REG of flipflops : signal is "true";
begin
o <= flipflops(flipflops'high);
clk_proc : process(clk, flipflops, i)
begin
if rising_edge(clk) then
flipflops <= flipflops(flipflops'high-1 downto 0) & i;
end if;
end process;
end Behavioral;
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