One Second Counter in VHDL for spartan3E

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Hi friends,

This is the vhdl code for LED blinking at 1 sec exactly.

I have a Papilio one which is running at 32MHz.

So all I had to do is count 32million (1111010000100100000000000 in binary) clock pulses to get one second.

Then I toggled the LED pin.

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity main is

     port (

              clk:in std_logic;

              led1:out std_logic;

              led2:out std_logic

              );           

    

end main;

architecture Behavioral of main is

     signal counter: std_logic_vector(26 downto 0) := (others =>'0');

     signal bit1:std_logic :='0';

     signal bit2:std_logic :='0';

begin

     timer_process:process(clk)

     begin

          if rising_edge(clk) then

              if (counter(24 downto 0) = "1111010000100100000000000") then --count upto 32M

                   led1 <= bit1;

                   led2 <= bit2;

                   counter <= (others =>'0') ;

                   bit1 <= not bit1;

                   bit2 <= not bit2;

              else

                   counter <= counter+1;

              end if;

          end if;

     end process;

end Behavioral;

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