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-- Company: 
-- Engineer: 
-- 
-- Create Date:    17:12:19 01/29/2011 
-- Design Name: 
-- Module Name:    tft_driver - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating
-- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity tft_driver is
    Port ( clock50 : in  STD_LOGIC;
           led : out std_logic;	
           tft_red : out  STD_LOGIC;
           tft_green : out  STD_LOGIC;
           tft_blue : out  STD_LOGIC;
           tft_hsync : out  STD_LOGIC;
           tft_vsync : out  STD_LOGIC;
           tft_den : out  STD_LOGIC;
           tft_clk : out  STD_LOGIC);
end tft_driver;

architecture Behavioral of tft_driver is

signal clk: std_logic;

signal hctr: std_logic_vector(9 downto 0);
signal vctr: std_logic_vector(9 downto 0);
signal ictr: std_logic_vector(5 downto 0);

signal ictr2: std_logic_vector(9 downto 0);

begin

tft_clk <= clk;

led <= ictr(5);

process (clock50)
begin
	if clock50'event and clock50='1' then
		if clk='1' then
			clk <= '0';
		else
			clk <= '1';
		end if;
	end if;
end process;

process (clk)
begin
	if clk'event and clk='1' then
		
		-- support counters
		-- --------------------------------------------------------------------
		hctr <= hctr + 1;
		if (hctr = 800) then -- 0x320 = 800
			hctr <= "0000000000";
			vctr <= vctr + 1;
		end if;
		if (vctr = 521) then -- 0x209 = 521
			vctr <= "0000000000";
			ictr <= ictr + 1;
			ictr2 <= ictr2 + 1;
		end if;
		if (ictr = 60) then
			ictr <= "000000";
		end if;
		if (ictr2 = 800) then
			ictr2 <= "0010100000"; -- 160 0xa0
		end if;
		
		-- vsync
		-- --------------------------------------------------------------------
		if (vctr >= 0 and vctr < 2) then
			tft_vsync <= '0';
		else
			tft_vsync <= '1';
		end if;
		
		-- hsync
		-- --------------------------------------------------------------------
		if (hctr >= 0 and hctr < 130) then
			tft_hsync <= '0';
		else
			tft_hsync <= '1';
		end if;
		
		-- data enable
		-- --------------------------------------------------------------------
		if (hctr >= 0 and hctr < 160) then
			tft_den <= '0';
		else
			if ((vctr >= 0 and vctr < 34) or vctr >= 514) then
				tft_den <= '0';
			else 
				tft_den <= '1';
			end if;
		end if;
		
		
		if (vctr = 34 or vctr = 513) then
			tft_red <= '1';
		else
			tft_red <= '0';
		end if;
		
		if (hctr = 160 or hctr = 799) then
			tft_green <= '1';
		else
			tft_green <= '0';
		end if;
		
		if (hctr = ictr2) then
			tft_blue <= '1';
		else
			tft_blue <= '0';
		end if;

	end if;
end process;

end Behavioral;