process(clk,rst)
begin
if rst = '1' then
cnti <= (others => '0');
clkd <= '0';
elsif clk = '1' and clk'event then
if cnti = 39999999 then cnti <= (others => '0');
else cnti <= cnti + 1;
end if;
if cnti = 39999999 then clkd <= not clkd; end if;
end if;
end process;