-- Top entity is DCT8_slow
-- ENTITY DCT8_slow IS
--    PORT( 
--       clk       : IN     std_logic  ;
--       dctselect : IN     std_logic  ;
--       din       : IN     std_logic  ;
--       mode      : IN     std_logic_vector (1 downto 0) ;
--       reset     : IN     std_logic  ;
--       doutput   : OUT    std_logic_vector (15 DOWNTO 0) ;
--       next_in   : OUT    std_logic  ;
--       read      : OUT    std_logic 
--    );
-- 
-- Please refer to the FreeDCT-L documentation
-- Sherif Taher Eid, sherif_taher@ieee.org
-- 

LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;

ENTITY add12slow IS
   PORT( 
      a      : IN     std_logic_vector (11 downto 0) ;
      b      : IN     std_logic_vector (11 downto 0) ;
      output : OUT    std_logic_vector (12 downto 0)
   );

-- Declarations

END add12slow ;
--
--
ARCHITECTURE beh OF add12slow IS
signal output_temp : unsigned(12 downto 0);
BEGIN
output_temp <= unsigned(a(11)&a) + unsigned(b(11)&b);
output <= std_logic_vector(output_temp);

END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;

ENTITY add16bits IS
   PORT( 
      a      : IN     std_logic_vector (15 downto 0) ;
      b      : IN     std_logic_vector (15 downto 0) ;
      output : OUT    std_logic_vector (15 downto 0)
   );

-- Declarations

END add16bits ;
--
--
ARCHITECTURE beh OF add16bits IS
signal output_temp : unsigned(15 downto 0);
BEGIN

output_temp <= unsigned(a) + unsigned(b);
output <= std_logic_vector(output_temp);

END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;

ENTITY and15 IS
   PORT( 
      enable : IN     std_logic  ;
      input  : IN     std_logic_vector (15 downto 0) ;
      output : OUT    std_logic_vector (15 downto 0)
   );

-- Declarations

END and15 ;
--
--
ARCHITECTURE struct OF and15 IS
BEGIN

with enable select
	output <= "0000000000001100" when '0',
				  input when others;

END struct;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
LIBRARY std ;
USE std.textio.all;

ENTITY cyclereg IS
   PORT( 
      ck         : IN     std_logic  ;
      din        : IN     std_logic  ;
      first      : IN     std_logic  ;
      mode       : IN     std_logic_vector (1 downto 0) ;
      rst        : IN     std_logic  ;
      enable_rom : OUT    std_logic 
   );

-- Declarations

END cyclereg ;
--
--
ARCHITECTURE beh OF cyclereg IS

signal internal : std_logic_vector(95 downto 0);
signal din_tmp : std_logic;
signal op_mode : std_logic_vector(2 downto 0);

BEGIN

op_mode <= first&mode;

with op_mode select
	din_tmp <= din when "100",
					din when "101",
					din when "110",
					din when "111",
					internal(63) when "000",
					internal(71) when "001",
					internal(79) when "010",
					internal(95) when others;

enable_rom <= internal(0);

process(ck,rst)
begin
	if rising_edge(ck) then
		if rst = '1' then
			internal <= (others => '0');
		elsif mode = "00" then -- 8 bits resolution mode
			internal(63 downto 1) <= internal(62 downto 0);
			internal(0) <= din_tmp;
		elsif mode = "01" then -- 9 bits resolution mode
			internal(71 downto 1) <= internal(70 downto 0);
			internal(0) <= din_tmp;
		elsif mode = "10" then -- 10 bits resolution mode
			internal(79 downto 1) <= internal(78 downto 0);
			internal(0) <= din_tmp;
		else							  -- 12 bits resolution mode
			internal(95 downto 1) <= internal(94 downto 0);
			internal(0) <= din_tmp;
		end if;
	end if;
end process;


END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;

ENTITY div2_9_en IS
   PORT( 
      ain    : IN     std_logic_vector (12 downto 0) ;
      enable : IN     std_logic  ;
      aout   : OUT    std_logic_vector (11 downto 0)
   );

-- Declarations

END div2_9_en ;
--
--
ARCHITECTURE struct OF div2_9_en IS

BEGIN

with enable select
	aout <= ain(12 downto 1) when '1',
				"000000000000" when others;
END struct;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;

ENTITY reg12bits IS
   PORT( 
      ain    : IN     std_logic_vector (11 downto 0) ;
      clk    : IN     std_logic  ;
      enable : IN     std_logic  ;
      aout   : OUT    std_logic_vector (11 downto 0)
   );

-- Declarations

END reg12bits ;
--
--
ARCHITECTURE beh OF reg12bits IS
BEGIN

process(clk,enable)
begin
	if enable = '0' then
		aout <= "000000000000";
	else
		if rising_edge(clk) then
			aout <= ain;
		end if;
	end if;
end process;


END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;

ENTITY reg13bits IS
   PORT( 
      ain    : IN     std_logic_vector (12 downto 0) ;
      clk    : IN     std_logic  ;
      enable : IN     std_logic  ;
      aout   : OUT    std_logic_vector (12 downto 0)
   );

-- Declarations

END reg13bits ;
--
--
ARCHITECTURE beh OF reg13bits IS
BEGIN

process(clk,enable)
begin
	if enable = '0' then
		aout <= "0000000000000";
	else
		if rising_edge(clk) then
			aout <= ain;
		end if;
	end if;
end process;

END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;

ENTITY reg16bits IS
   PORT( 
      ain    : IN     std_logic_vector (15 downto 0) ;
      clk    : IN     std_logic  ;
      enable : IN     std_logic  ;
      aout   : OUT    std_logic_vector (15 downto 0)
   );

-- Declarations

END reg16bits ;
--
--
ARCHITECTURE beh OF reg16bits IS
BEGIN

process(clk,enable)
begin
	if enable = '0' then
		aout <= "0000000000000000";
	else
		if rising_edge(clk) then
			aout <= ain;
		end if;
	end if;
end process;

END beh;

--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;

ENTITY ROM64 IS
   PORT( 
      columns    : IN     std_logic_vector (2 downto 0) ;
      compl      : IN     std_logic  ;
      enable_rom : IN     std_logic  ;
      rows       : IN     std_logic_vector (2 downto 0) ;
      output     : OUT    std_logic_vector (11 DOWNTO 0)
   );

-- Declarations

END ROM64 ;
--
--
ARCHITECTURE beh OF ROM64 IS


-- ROM used for Forward Discrete Cosine Transform
type ROM_array is array (63 downto 0) of std_logic_vector(11 downto 0);

signal coeff_out : std_logic_vector(11 downto 0);
signal rt,ct : unsigned(2 downto 0);
--signal cmp_c1 : unsigned(11 downto 0);
signal cmp_c2 : std_logic_vector(11 downto 0);
--signal nottemp : std_logic_vector(7 downto 0);

signal coeff: ROM_array;
signal addr : integer range 0 to 63;
--signal ap : std_logic_vector(7 downto 0) := "01011011";
--signal bp : std_logic_vector(7 downto 0) := "01110110";
--signal cp : std_logic_vector(7 downto 0) := "00110001";
--signal dp : std_logic_vector(7 downto 0) := "01111110";
--signal ep : std_logic_vector(7 downto 0) := "01101010";
--signal fp : std_logic_vector(7 downto 0) := "01000111";
--signal gp : std_logic_vector(7 downto 0) := "00011001";

--signal am : std_logic_vector(7 downto 0) := "10100101";
--signal bm : std_logic_vector(7 downto 0) := "10001010";
--signal cm : std_logic_vector(7 downto 0) := "11001111";
--signal dm : std_logic_vector(7 downto 0) := "10000010";
--signal em : std_logic_vector(7 downto 0) := "10010110";
--signal fm : std_logic_vector(7 downto 0) := "10111001";
--signal gm : std_logic_vector(7 downto 0) := "11100111";

signal ap : std_logic_vector(11 downto 0) := "010110101000";
signal bp : std_logic_vector(11 downto 0) := "011101100100";
signal cp : std_logic_vector(11 downto 0) := "001100010000";
signal dp : std_logic_vector(11 downto 0) := "011111011001";
signal ep : std_logic_vector(11 downto 0) := "011010100111";
signal fp : std_logic_vector(11 downto 0) := "010001110010";
signal gp : std_logic_vector(11 downto 0) := "000110010000";

signal am : std_logic_vector(11 downto 0) := "101001011000";
signal bm : std_logic_vector(11 downto 0) := "100010011100";
signal cm : std_logic_vector(11 downto 0) := "110011110000";
signal dm : std_logic_vector(11 downto 0) := "100000100111";
signal em : std_logic_vector(11 downto 0) := "100101011001";
signal fm : std_logic_vector(11 downto 0) := "101110001110";
signal gm : std_logic_vector(11 downto 0) := "111001110000";


BEGIN

coeff(0) <= ap;    --     A
coeff(1) <= ap;    --     A
coeff(2) <= ap;    --     A
coeff(3) <= ap;    --     A
coeff(4) <= ap;    --     A
coeff(5) <= ap;    --     A
coeff(6) <= ap;    --     A
coeff(7) <= ap;    --     A

coeff(8) <= dp;    --     D
coeff(9) <= ep;    --     E
coeff(10) <= fp;   --     F
coeff(11) <= gp;   --     G
coeff(12) <= gm;   --    -G
coeff(13) <= fm;   --    -F   
coeff(14) <= em;   --    -E
coeff(15) <= dm;   --    -D

coeff(16) <= bp;   --     B
coeff(17) <= cp;   --     C
coeff(18) <= cm;   --    -C
coeff(19) <= bm;   --    -B
coeff(20) <= bm;   --    -B
coeff(21) <= cm;   --    -C
coeff(22) <= cp;   --     C
coeff(23) <= bp;   --     B

coeff(24) <= ep;   --     E
coeff(25) <= gm;   --    -G
coeff(26) <= dm;   --    -D
coeff(27) <= fm;   --    -F
coeff(28) <= fp;   --     F
coeff(29) <= dp;   --     D
coeff(30) <= gp;   --     G
coeff(31) <= em;   --    -E

coeff(32) <= ap;   --     A
coeff(33) <= am;   --    -A
coeff(34) <= am;   --    -A
coeff(35) <= ap;   --     A
coeff(36) <= ap;   --     A
coeff(37) <= am;   --    -A
coeff(38) <= am;   --    -A
coeff(39) <= ap;   --     A

coeff(40) <= fp;   --     F
coeff(41) <= dm;   --    -D
coeff(42) <= gp;   --     G
coeff(43) <= ep;   --     E
coeff(44) <= em;   --    -E
coeff(45) <= gm;   --    -G
coeff(46) <= dp;   --     D
coeff(47) <= fm;   --    -F

coeff(48) <= cp;   --     C
coeff(49) <= bm;   --    -B
coeff(50) <= bp;   --     B
coeff(51) <= cm;   --    -C
coeff(52) <= cm;   --    -C
coeff(53) <= bp;   --     B
coeff(54) <= bm;   --    -B
coeff(55) <= cp;   --     C

coeff(56) <= gp;   --     G
coeff(57) <= fm;   --    -F
coeff(58) <= ep;   --     E
coeff(59) <= dm;   --    -D
coeff(60) <= dp;   --     D
coeff(61) <= em;   --    -E
coeff(62) <= fp;   --     F
coeff(63) <= gm;   --    -G

rt <= unsigned(rows);
ct <= unsigned(columns);
addr <= CONV_INTEGER(rt&ct);

with enable_rom select
coeff_out <= coeff(addr) when '1',
			     "000000000000" when others;

--nottemp <= not(coeff_out);
--cmp_c1 <= unsigned(nottemp) + "000000000001";
--cmp_c2 <= std_logic_vector(cmp_c1);
cmp_c2 <= not(coeff_out);

with compl select
output <= cmp_c2 when '1',
	  coeff_out when others;
	
END beh;
--
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;