library IEEE;

use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity buzz is
    port (
        clock : in std_logic;
        a     : out std_logic
    );
end buzz;

architecture Behavioral of buzz is

begin

    process(clock)
        variable i : integer := 0;
    begin
        if clock'event and clock = '1' then
            if i <= 50000000 then
                i := i + 1;
                a <= '1';
            elsif i > 50000000 and i < 100000000 then
                i := i + 1;
                a <= '0';
            elsif i = 100000000 then
                i := 0;
            end if;
        end if;
    end process;

end Behavioral;