LED blinking with Spartan3E

Hi friends,
I just bought Papilio one FPGA development board and started to learn Spartan3E.
Here is a cool video to start with Xilinx  ISE development.

 The person explained well with another Spartan3E board but most of things remain the same.....

Here is the counter designed for Papilio One in VHDL.
Here the counter is a 30 bit counter and 22nd and 23rd pins are connected to led. Actually i was not aware when I can see LED blinking so I set a large counter and experimented by trial.

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

use IEEE.STD_LOGIC_ARITH.all;

entity LEDs is

             Port (

                          LED1 : out STD_LOGIC;

                          LED2 : out STD_LOGIC;

                          LED3 : out STD_LOGIC;

                          clk : in STD_LOGIC

                      );

end LEDs;

architecture Behavioral of LEDs is

             signal counter : STD_LOGIC_VECTOR(29 downto 0) := (others => '0');

             begin

        

                 clk_proc: process(clk)

                 begin

                      if rising_edge(clk) then

                               counter <= counter+1;

                               LED1 <= counter(23);

                               LED2 <= counter(22);

                               LED3 <= '1';

                      end if;

                 end process;

end Behavioral;