URL https://opencores.org/ocsvn/mkjpeg/mkjpeg/trunk

Subversion Repositories mkjpeg

[/] [mkjpeg/] [trunk/] [design/] [huffman/] [Huffman.vhd] - Blame information for rev 34

Go to most recent revision | Details | Compare with Previous | View Log


-------------------------------------------------------------------------------
-- File Name :  Huffman.vhd
--
-- Project   : JPEG_ENC
--
-- Module    : Huffman
--
-- Content   : Huffman Encoder
--
-- Description : Huffman encoder core
--
-- Spec.     : 
--
-- Author    : Michal Krepa
--
-------------------------------------------------------------------------------
-- History :
-- 20090228: (MK): Initial Creation.
-------------------------------------------------------------------------------
 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
----------------------------------- LIBRARY/PACKAGE ---------------------------
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
 
-------------------------------------------------------------------------------
-- generic packages/libraries:
-------------------------------------------------------------------------------
library ieee;
  use ieee.std_logic_1164.all;
  use ieee.numeric_std.all;
 
-------------------------------------------------------------------------------
-- user packages/libraries:
-------------------------------------------------------------------------------
 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
----------------------------------- ENTITY ------------------------------------
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
entity Huffman is
  port
  (
        CLK                : in  std_logic;
        RST                : in  std_logic;
        -- CTRL
        start_pb           : in  std_logic;
        ready_pb           : out std_logic;
 
        -- HOST IF
        sof                : in  std_logic;
        img_size_x         : in  std_logic_vector(15 downto 0);
        img_size_y         : in  std_logic_vector(15 downto 0);
        cmp_max            : in  std_logic_vector(1 downto 0);
 
        -- RLE
        rle_buf_sel        : out std_logic;
        rd_en              : out std_logic;
        runlength          : in  std_logic_vector(3 downto 0);
        VLI_size           : in  std_logic_vector(3 downto 0);
        VLI                : in  std_logic_vector(11 downto 0);
        d_val              : in  std_logic;
        rle_fifo_empty     : in  std_logic;
 
        -- Byte Stuffer
        bs_buf_sel         : in  std_logic;
        bs_fifo_empty      : out std_logic;
        bs_rd_req          : in  std_logic;
        bs_packed_byte     : out std_logic_vector(7 downto 0)
    );
end entity Huffman;
 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
----------------------------------- ARCHITECTURE ------------------------------
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
architecture RTL of Huffman is
 
  type T_STATE is (IDLE, RUN_VLC, RUN_VLI, PAD);
 
  constant C_M             : integer := 23;
  constant BLK_SIZE        : integer := 64;
 
  signal state             : T_STATE;
  signal rle_buf_sel_s     : std_logic;
  signal first_rle_word    : std_logic;
  signal word_reg          : unsigned(C_M-1 downto 0);
  signal bit_ptr           : unsigned(4 downto 0);
  signal num_fifo_wrs      : unsigned(1 downto 0);
  signal VLI_ext           : unsigned(15 downto 0);
  signal VLI_ext_size      : unsigned(4 downto 0);
  signal ready_HFW         : std_logic;
  signal fifo_wbyte        : std_logic_vector(7 downto 0);
  signal fifo_wrt_cnt      : unsigned(1 downto 0);
  signal fifo_wren         : std_logic;
  signal last_block        : std_logic;
  signal image_area_size   : unsigned(33 downto 0);
  signal block_cnt         : unsigned(27 downto 0);
  signal VLC_size          : unsigned(4 downto 0);
  signal VLC               : unsigned(15 downto 0);
  signal VLC_DC_size       : std_logic_vector(3 downto 0);
  signal VLC_DC            : unsigned(8 downto 0);
  signal VLC_AC_size       : unsigned(4 downto 0);
  signal VLC_AC            : unsigned(15 downto 0);
  signal vlc_vld           : std_logic;
  signal d_val_d1          : std_logic;
  signal d_val_d2          : std_logic;
  signal d_val_d3          : std_logic;
  signal d_val_d4          : std_logic;
  signal VLI_size_d        : std_logic_vector(3 downto 0);
  signal VLI_d             : std_logic_vector(11 downto 0);
  signal VLI_size_d1       : std_logic_vector(3 downto 0);
  signal VLI_d1            : std_logic_vector(11 downto 0);
  signal HFW_running       : std_logic;
  signal runlength_r       : std_logic_vector(3 downto 0);
  signal VLI_size_r        : std_logic_vector(3 downto 0);
  signal VLI_r             : std_logic_vector(11 downto 0);
  signal rd_en_s           : std_logic;
  signal pad_byte          : std_logic_vector(7 downto 0);
  signal pad_reg           : std_logic;
 
-------------------------------------------------------------------------------
-- Architecture: begin
-------------------------------------------------------------------------------
begin
 
  rle_buf_sel <= rle_buf_sel_s;
 
  rd_en   <= rd_en_s;
  vlc_vld <= rd_en_s;
 
  -------------------------------------------------------------------
  -- latch FIFO Q
  -------------------------------------------------------------------
  p_latch_fifo : process(CLK, RST)
  begin
    if RST = '1' then
      VLI_size_r  <= (others => '0');
      VLI_r       <= (others => '0');
    elsif CLK'event and CLK = '1' then
      if d_val = '1' then
        VLI_size_r  <= VLI_size;
        VLI_r       <= VLI;
      end if;
    end if;
  end process;
 
  -------------------------------------------------------------------
  -- DC_ROM
  -------------------------------------------------------------------
  U_DC_ROM : entity work.DC_ROM
  port map
  (
        CLK                => CLK,
        RST                => RST,
        VLI_size           => VLI_size,
 
        VLC_DC_size        => VLC_DC_size,
        VLC_DC             => VLC_DC
  );
 
  -------------------------------------------------------------------
  -- AC_ROM
  -------------------------------------------------------------------
  U_AC_ROM : entity work.AC_ROM
  port map
  (
        CLK                => CLK,
        RST                => RST,
        runlength          => runlength,
        VLI_size           => VLI_size,
 
        VLC_AC_size        => VLC_AC_size,
        VLC_AC             => VLC_AC
    );
 
  -------------------------------------------------------------------
  -- Double Fifo
  -------------------------------------------------------------------
  U_DoubleFifo : entity work.DoubleFifo
  port map
  (
        CLK                => CLK,
        RST                => RST,
        -- HUFFMAN
        data_in            => fifo_wbyte,
        wren               => fifo_wren,
        -- BYTE STUFFER
        buf_sel            => bs_buf_sel,
        rd_req             => bs_rd_req,
        fifo_empty         => bs_fifo_empty,
        data_out           => bs_packed_byte
    );
 
  -------------------------------------------------------------------
  -- RLE buf_sel
  -------------------------------------------------------------------
  p_rle_buf_sel : process(CLK, RST)
  begin
    if RST = '1' then
      rle_buf_sel_s   <= '0';
    elsif CLK'event and CLK = '1' then
      if start_pb = '1' then
        rle_buf_sel_s <= not rle_buf_sel_s;
      end if;
    end if;
  end process;
 
  -------------------------------------------------------------------
  -- mux for DC/AC ROM
  -------------------------------------------------------------------
  p_mux : process(CLK, RST)
  begin
    if RST = '1' then
      VLC_size <= (others => '0');
      VLC      <= (others => '0');
    elsif CLK'event and CLK = '1' then
      if first_rle_word = '1' then
        VLC_size <= unsigned('0' & VLC_DC_size);
        VLC      <= resize(VLC_DC, VLC'length);
      else
        VLC_size <= VLC_AC_size;
        VLC      <= VLC_AC;
      end if;
    end if;
  end process;
 
  -------------------------------------------------------------------
  -- Block Counter / Last Block detector
  -------------------------------------------------------------------
  p_blk_cnt : process(CLK, RST)
  begin
    if RST = '1' then
      image_area_size <= (others => '0');
      last_block      <= '0';
    elsif CLK'event and CLK = '1' then
      image_area_size <= unsigned(cmp_max)*
                         unsigned(img_size_x)*unsigned(img_size_y);
 
      if sof = '1' then
        block_cnt <= (others => '0');
      elsif start_pb = '1' then
        block_cnt <= block_cnt + 1;
      end if;
 
      if block_cnt = image_area_size(33 downto 6) then
        last_block <= '1';
      else
        last_block <= '0';
      end if;
 
    end if;
  end process;
 
  VLI_ext      <= unsigned("0000" & VLI_d1);
  VLI_ext_size <= unsigned('0' & VLI_size_d1);
 
  -------------------------------------------------------------------
  -- delay line
  -------------------------------------------------------------------
  p_vli_dly : process(CLK, RST)
  begin
    if RST = '1' then
      VLI_d       <= (others => '0');
      VLI_size_d  <= (others => '0');
      VLI_d1      <= (others => '0');
      VLI_size_d1 <= (others => '0');
      d_val_d1    <= '0';
      d_val_d2    <= '0';
      d_val_d3    <= '0';
      d_val_d4    <= '0';
    elsif CLK'event and CLK = '1' then
      VLI_d1      <= VLI_r;
      VLI_size_d1 <= VLI_size_r;
 
      VLI_d       <= VLI_d1;
      VLI_size_d  <= VLI_size_d1;
 
      d_val_d1   <= d_val;
      d_val_d2   <= d_val_d1;
      d_val_d3   <= d_val_d2;
      d_val_d4   <= d_val_d3;
    end if;
  end process;
 
  -------------------------------------------------------------------
  -- HandleFifoWrites
  -------------------------------------------------------------------
  p_HandleFifoWrites : process(CLK, RST)
  begin
    if RST = '1' then
      ready_HFW    <= '0';
      fifo_wrt_cnt <= (others => '0');
      fifo_wren    <= '0';
      fifo_wbyte   <= (others => '0');
      rd_en_s      <= '0';
    elsif CLK'event and CLK = '1' then
      fifo_wren <= '0';
      ready_HFW <= '0';
      rd_en_s   <= '0';
 
      if start_pb = '1' then
        rd_en_s     <= '1';
      end if;
 
      if HFW_running = '1' and ready_HFW = '0' then
        -- there is no at least one integer byte to write this time
        if num_fifo_wrs = 0 then
          ready_HFW    <= '1';
          if state = RUN_VLI then
            rd_en_s      <= '1';
          end if;
        -- single byte write to FIFO
        else
          fifo_wrt_cnt <= fifo_wrt_cnt + 1;
          fifo_wren    <= '1';
          -- last byte write
          if fifo_wrt_cnt + 1 = num_fifo_wrs then
            ready_HFW    <= '1';
            if state = RUN_VLI then
              rd_en_s      <= '1';
            end if;
            fifo_wrt_cnt <= (others => '0');
          end if;
        end if;
      end if;
 
      case fifo_wrt_cnt is
        when "00" =>
          fifo_wbyte <= std_logic_vector(word_reg(C_M-1 downto C_M-8));
        when "01" =>
          fifo_wbyte <= std_logic_vector(word_reg(C_M-8-1 downto C_M-16));
        when others =>
          fifo_wbyte <= (others => '0');
      end case;
      if pad_reg = '1' then
        fifo_wbyte <= pad_byte;
      end if;
 
 
    end if;
  end process;
 
  -- divide by 8
  num_fifo_wrs <= bit_ptr(4 downto 3);
 
  -------------------------------------------------------------------
  -- Variable Length Processor FSM
  -------------------------------------------------------------------
  p_vlp : process(CLK, RST)
  begin
    if RST = '1' then
      ready_pb     <= '0';
      first_rle_word <= '0';
      state        <= IDLE;
      word_reg     <= (others => '0');
      bit_ptr      <= (others => '0');
      HFW_running  <= '0';
      pad_reg      <= '0';
      pad_byte     <= (others => '0');
    elsif CLK'event and CLK = '1' then
      ready_pb  <= '0';
 
      case state is
 
        when IDLE =>
          if start_pb = '1' then
            first_rle_word <= '1';
            state       <= RUN_VLC;
          end if;
 
        when RUN_VLC =>
          -- data valid DC or data valid AC
          if (d_val_d2 = '1' and first_rle_word = '1') or
             (d_val = '1' and first_rle_word = '0') then
            for i in 0 to C_M-1 loop
              if i < to_integer(VLC_size) then
                word_reg(C_M-1-to_integer(bit_ptr)-i) <= VLC(to_integer(VLC_size)-1-i);
              end if;
            end loop;
            bit_ptr <= bit_ptr + resize(VLC_size,bit_ptr'length);
 
            -- HandleFifoWrites
            HFW_running  <= '1';
          -- HandleFifoWrites completed
          elsif HFW_running = '1' and
                (num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then
            -- shift word reg left to skip bytes already written to FIFO
            word_reg <= shift_left(word_reg, to_integer(num_fifo_wrs & "000"));
            -- adjust bit pointer after some bytes were written to FIFO
            -- modulo 8 operation
            bit_ptr <= bit_ptr - (num_fifo_wrs & "000");
            HFW_running     <= '0';
            first_rle_word  <= '0';
            state           <= RUN_VLI;
          end if;
 
        when RUN_VLI =>
          if HFW_running = '0' then
 
            for i in 0 to C_M-1 loop
              if i < to_integer(VLI_ext_size) then
                word_reg(C_M-1-to_integer(bit_ptr)-i)
                  <= VLI_ext(to_integer(VLI_ext_size)-1-i);
              end if;
            end loop;
 
            bit_ptr <= bit_ptr + resize(VLI_ext_size,bit_ptr'length);
 
            -- HandleFifoWrites
            HFW_running <= '1';
          -- HandleFifoWrites completed
          elsif HFW_running = '1' and
                (num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then
            -- shift word reg left to skip bytes already written to FIFO
            word_reg <= shift_left(word_reg, to_integer(num_fifo_wrs & "000"));
            -- adjust bit pointer after some bytes were written to FIFO
            -- modulo 8 operation
            bit_ptr <= bit_ptr - (num_fifo_wrs & "000");
            HFW_running <= '0';
 
            -- end of block
            if rle_fifo_empty = '1' then
              -- end of segment
              if bit_ptr - (num_fifo_wrs & "000") /= 0 and last_block = '1' then
                state <= PAD;
              else
                ready_pb <= '1';
                state    <= IDLE;
              end if;
            else
              state          <= RUN_VLC;
            end if;
          end if;
 
        -- end of segment which requires bit padding
        when PAD =>
          if HFW_running = '0' then
            -- 1's bit padding to integer number of bytes
            for i in 0 to 7 loop
              if i < bit_ptr then
                pad_byte(7-i) <= word_reg(C_M-1-i);
              else
                pad_byte(7-i) <= '1';
              end if;
            end loop;
            pad_reg <= '1';
 
            bit_ptr <= to_unsigned(8, bit_ptr'length);
 
            -- HandleFifoWrites
            HFW_running <= '1';
         elsif HFW_running = '1' and
                (num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then
           bit_ptr      <= (others => '0');
           HFW_running  <= '0';
           pad_reg      <= '0';
 
           ready_pb <= '1';
           state <= IDLE;
         end if;
 
        when others =>
 
      end case;
 
      if sof = '1' then
        bit_ptr <= (others => '0');
      end if;
 
    end if;
  end process;
 
 
end architecture RTL;
-------------------------------------------------------------------------------
-- Architecture: end
-------------------------------------------------------------------------------

Browse

Tools

Subversion Repositories mkjpeg

[/] [mkjpeg/] [trunk/] [design/] [huffman/] [Huffman.vhd] - Blame information for rev 34

Line No.	Rev	Author	Line
1	25	mikel262	`-------------------------------------------------------------------------------`
2			`-- File Name : Huffman.vhd`
3			`--`
4			`-- Project : JPEG_ENC`
5			`--`
6			`-- Module : Huffman`
7			`--`
8			`-- Content : Huffman Encoder`
9			`--`
10			`-- Description : Huffman encoder core`
11			`--`
12			`-- Spec. :`
13			`--`
14			`-- Author : Michal Krepa`
15			`--`
16			`-------------------------------------------------------------------------------`
17			`-- History :`
18			`-- 20090228: (MK): Initial Creation.`
19			`-------------------------------------------------------------------------------`
20
21			`-------------------------------------------------------------------------------`
22			`-------------------------------------------------------------------------------`
23			`----------------------------------- LIBRARY/PACKAGE ---------------------------`
24			`-------------------------------------------------------------------------------`
25			`-------------------------------------------------------------------------------`
26
27			`-------------------------------------------------------------------------------`
28			`-- generic packages/libraries:`
29			`-------------------------------------------------------------------------------`
30			`library ieee;`
31			`use ieee.std_logic_1164.all;`
32			`use ieee.numeric_std.all;`
33
34			`-------------------------------------------------------------------------------`
35			`-- user packages/libraries:`
36			`-------------------------------------------------------------------------------`
37
38			`-------------------------------------------------------------------------------`
39			`-------------------------------------------------------------------------------`
40			`----------------------------------- ENTITY ------------------------------------`
41			`-------------------------------------------------------------------------------`
42			`-------------------------------------------------------------------------------`
43			`entity Huffman is`
44			`port`
45			`(`
46			`CLK : in std_logic;`
47			`RST : in std_logic;`
48			`-- CTRL`
49			`start_pb : in std_logic;`
50			`ready_pb : out std_logic;`
51
52			`-- HOST IF`
53			`sof : in std_logic;`
54			`img_size_x : in std_logic_vector(15 downto 0);`
55			`img_size_y : in std_logic_vector(15 downto 0);`
56			`cmp_max : in std_logic_vector(1 downto 0);`
57
58			`-- RLE`
59			`rle_buf_sel : out std_logic;`
60			`rd_en : out std_logic;`
61			`runlength : in std_logic_vector(3 downto 0);`
62			`VLI_size : in std_logic_vector(3 downto 0);`
63			`VLI : in std_logic_vector(11 downto 0);`
64			`d_val : in std_logic;`
65			`rle_fifo_empty : in std_logic;`
66
67			`-- Byte Stuffer`
68			`bs_buf_sel : in std_logic;`
69			`bs_fifo_empty : out std_logic;`
70			`bs_rd_req : in std_logic;`
71			`bs_packed_byte : out std_logic_vector(7 downto 0)`
72			`);`
73			`end entity Huffman;`
74
75			`-------------------------------------------------------------------------------`
76			`-------------------------------------------------------------------------------`
77			`----------------------------------- ARCHITECTURE ------------------------------`
78			`-------------------------------------------------------------------------------`
79			`-------------------------------------------------------------------------------`
80			`architecture RTL of Huffman is`
81
82			`type T_STATE is (IDLE, RUN_VLC, RUN_VLI, PAD);`
83
84			`constant C_M : integer := 23;`
85			`constant BLK_SIZE : integer := 64;`
86
87			`signal state : T_STATE;`
88			`signal rle_buf_sel_s : std_logic;`
89			`signal first_rle_word : std_logic;`
90			`signal word_reg : unsigned(C_M-1 downto 0);`
91			`signal bit_ptr : unsigned(4 downto 0);`
92			`signal num_fifo_wrs : unsigned(1 downto 0);`
93			`signal VLI_ext : unsigned(15 downto 0);`
94			`signal VLI_ext_size : unsigned(4 downto 0);`
95			`signal ready_HFW : std_logic;`
96			`signal fifo_wbyte : std_logic_vector(7 downto 0);`
97			`signal fifo_wrt_cnt : unsigned(1 downto 0);`
98			`signal fifo_wren : std_logic;`
99			`signal last_block : std_logic;`
100			`signal image_area_size : unsigned(33 downto 0);`
101			`signal block_cnt : unsigned(27 downto 0);`
102			`signal VLC_size : unsigned(4 downto 0);`
103			`signal VLC : unsigned(15 downto 0);`
104			`signal VLC_DC_size : std_logic_vector(3 downto 0);`
105			`signal VLC_DC : unsigned(8 downto 0);`
106			`signal VLC_AC_size : unsigned(4 downto 0);`
107			`signal VLC_AC : unsigned(15 downto 0);`
108			`signal vlc_vld : std_logic;`
109			`signal d_val_d1 : std_logic;`
110			`signal d_val_d2 : std_logic;`
111			`signal d_val_d3 : std_logic;`
112			`signal d_val_d4 : std_logic;`
113			`signal VLI_size_d : std_logic_vector(3 downto 0);`
114			`signal VLI_d : std_logic_vector(11 downto 0);`
115			`signal VLI_size_d1 : std_logic_vector(3 downto 0);`
116			`signal VLI_d1 : std_logic_vector(11 downto 0);`
117			`signal HFW_running : std_logic;`
118			`signal runlength_r : std_logic_vector(3 downto 0);`
119			`signal VLI_size_r : std_logic_vector(3 downto 0);`
120			`signal VLI_r : std_logic_vector(11 downto 0);`
121			`signal rd_en_s : std_logic;`
122			`signal pad_byte : std_logic_vector(7 downto 0);`
123			`signal pad_reg : std_logic;`
124
125			`-------------------------------------------------------------------------------`
126			`-- Architecture: begin`
127			`-------------------------------------------------------------------------------`
128			`begin`
129
130			`rle_buf_sel <= rle_buf_sel_s;`
131
132			`rd_en <= rd_en_s;`
133			`vlc_vld <= rd_en_s;`
134
135			`-------------------------------------------------------------------`
136			`-- latch FIFO Q`
137			`-------------------------------------------------------------------`
138			`p_latch_fifo : process(CLK, RST)`
139			`begin`
140			`if RST = '1' then`
141			`VLI_size_r <= (others => '0');`
142			`VLI_r <= (others => '0');`
143			`elsif CLK'event and CLK = '1' then`
144			`if d_val = '1' then`
145			`VLI_size_r <= VLI_size;`
146			`VLI_r <= VLI;`
147			`end if;`
148			`end if;`
149			`end process;`
150
151			`-------------------------------------------------------------------`
152			`-- DC_ROM`
153			`-------------------------------------------------------------------`
154			`U_DC_ROM : entity work.DC_ROM`
155			`port map`
156			`(`
157			`CLK => CLK,`
158			`RST => RST,`
159			`VLI_size => VLI_size,`
160
161			`VLC_DC_size => VLC_DC_size,`
162			`VLC_DC => VLC_DC`
163			`);`
164
165			`-------------------------------------------------------------------`
166			`-- AC_ROM`
167			`-------------------------------------------------------------------`
168			`U_AC_ROM : entity work.AC_ROM`
169			`port map`
170			`(`
171			`CLK => CLK,`
172			`RST => RST,`
173			`runlength => runlength,`
174			`VLI_size => VLI_size,`
175
176			`VLC_AC_size => VLC_AC_size,`
177			`VLC_AC => VLC_AC`
178			`);`
179
180			`-------------------------------------------------------------------`
181			`-- Double Fifo`
182			`-------------------------------------------------------------------`
183			`U_DoubleFifo : entity work.DoubleFifo`
184			`port map`
185			`(`
186			`CLK => CLK,`
187			`RST => RST,`
188			`-- HUFFMAN`
189			`data_in => fifo_wbyte,`
190			`wren => fifo_wren,`
191			`-- BYTE STUFFER`
192			`buf_sel => bs_buf_sel,`
193			`rd_req => bs_rd_req,`
194			`fifo_empty => bs_fifo_empty,`
195			`data_out => bs_packed_byte`
196			`);`
197
198			`-------------------------------------------------------------------`
199			`-- RLE buf_sel`
200			`-------------------------------------------------------------------`
201			`p_rle_buf_sel : process(CLK, RST)`
202			`begin`
203			`if RST = '1' then`
204			`rle_buf_sel_s <= '0';`
205			`elsif CLK'event and CLK = '1' then`
206			`if start_pb = '1' then`
207			`rle_buf_sel_s <= not rle_buf_sel_s;`
208			`end if;`
209			`end if;`
210			`end process;`
211
212			`-------------------------------------------------------------------`
213			`-- mux for DC/AC ROM`
214			`-------------------------------------------------------------------`
215			`p_mux : process(CLK, RST)`
216			`begin`
217			`if RST = '1' then`
218			`VLC_size <= (others => '0');`
219			`VLC <= (others => '0');`
220			`elsif CLK'event and CLK = '1' then`
221			`if first_rle_word = '1' then`
222			`VLC_size <= unsigned('0' & VLC_DC_size);`
223			`VLC <= resize(VLC_DC, VLC'length);`
224			`else`
225			`VLC_size <= VLC_AC_size;`
226			`VLC <= VLC_AC;`
227			`end if;`
228			`end if;`
229			`end process;`
230
231			`-------------------------------------------------------------------`
232			`-- Block Counter / Last Block detector`
233			`-------------------------------------------------------------------`
234			`p_blk_cnt : process(CLK, RST)`
235			`begin`
236			`if RST = '1' then`
237			`image_area_size <= (others => '0');`
238			`last_block <= '0';`
239			`elsif CLK'event and CLK = '1' then`
240			`image_area_size <= unsigned(cmp_max)*`
241			`unsigned(img_size_x)*unsigned(img_size_y);`
242
243			`if sof = '1' then`
244			`block_cnt <= (others => '0');`
245			`elsif start_pb = '1' then`
246			`block_cnt <= block_cnt + 1;`
247			`end if;`
248
249			`if block_cnt = image_area_size(33 downto 6) then`
250			`last_block <= '1';`
251			`else`
252			`last_block <= '0';`
253			`end if;`
254
255			`end if;`
256			`end process;`
257
258			`VLI_ext <= unsigned("0000" & VLI_d1);`
259			`VLI_ext_size <= unsigned('0' & VLI_size_d1);`
260
261			`-------------------------------------------------------------------`
262			`-- delay line`
263			`-------------------------------------------------------------------`
264			`p_vli_dly : process(CLK, RST)`
265			`begin`
266			`if RST = '1' then`
267			`VLI_d <= (others => '0');`
268			`VLI_size_d <= (others => '0');`
269			`VLI_d1 <= (others => '0');`
270			`VLI_size_d1 <= (others => '0');`
271			`d_val_d1 <= '0';`
272			`d_val_d2 <= '0';`
273			`d_val_d3 <= '0';`
274			`d_val_d4 <= '0';`
275			`elsif CLK'event and CLK = '1' then`
276			`VLI_d1 <= VLI_r;`
277			`VLI_size_d1 <= VLI_size_r;`
278
279			`VLI_d <= VLI_d1;`
280			`VLI_size_d <= VLI_size_d1;`
281
282			`d_val_d1 <= d_val;`
283			`d_val_d2 <= d_val_d1;`
284			`d_val_d3 <= d_val_d2;`
285			`d_val_d4 <= d_val_d3;`
286			`end if;`
287			`end process;`
288
289			`-------------------------------------------------------------------`
290			`-- HandleFifoWrites`
291			`-------------------------------------------------------------------`
292			`p_HandleFifoWrites : process(CLK, RST)`
293			`begin`
294			`if RST = '1' then`
295			`ready_HFW <= '0';`
296			`fifo_wrt_cnt <= (others => '0');`
297			`fifo_wren <= '0';`
298			`fifo_wbyte <= (others => '0');`
299			`rd_en_s <= '0';`
300			`elsif CLK'event and CLK = '1' then`
301			`fifo_wren <= '0';`
302			`ready_HFW <= '0';`
303			`rd_en_s <= '0';`
304
305			`if start_pb = '1' then`
306			`rd_en_s <= '1';`
307			`end if;`
308
309			`if HFW_running = '1' and ready_HFW = '0' then`
310			`-- there is no at least one integer byte to write this time`
311			`if num_fifo_wrs = 0 then`
312			`ready_HFW <= '1';`
313			`if state = RUN_VLI then`
314			`rd_en_s <= '1';`
315			`end if;`
316			`-- single byte write to FIFO`
317			`else`
318			`fifo_wrt_cnt <= fifo_wrt_cnt + 1;`
319			`fifo_wren <= '1';`
320			`-- last byte write`
321			`if fifo_wrt_cnt + 1 = num_fifo_wrs then`
322			`ready_HFW <= '1';`
323			`if state = RUN_VLI then`
324			`rd_en_s <= '1';`
325			`end if;`
326			`fifo_wrt_cnt <= (others => '0');`
327			`end if;`
328			`end if;`
329			`end if;`
330
331			`case fifo_wrt_cnt is`
332			`when "00" =>`
333			`fifo_wbyte <= std_logic_vector(word_reg(C_M-1 downto C_M-8));`
334			`when "01" =>`
335			`fifo_wbyte <= std_logic_vector(word_reg(C_M-8-1 downto C_M-16));`
336			`when others =>`
337			`fifo_wbyte <= (others => '0');`
338			`end case;`
339			`if pad_reg = '1' then`
340			`fifo_wbyte <= pad_byte;`
341			`end if;`
342
343
344			`end if;`
345			`end process;`
346
347			`-- divide by 8`
348			`num_fifo_wrs <= bit_ptr(4 downto 3);`
349
350			`-------------------------------------------------------------------`
351			`-- Variable Length Processor FSM`
352			`-------------------------------------------------------------------`
353			`p_vlp : process(CLK, RST)`
354			`begin`
355			`if RST = '1' then`
356			`ready_pb <= '0';`
357			`first_rle_word <= '0';`
358			`state <= IDLE;`
359			`word_reg <= (others => '0');`
360			`bit_ptr <= (others => '0');`
361			`HFW_running <= '0';`
362			`pad_reg <= '0';`
363			`pad_byte <= (others => '0');`
364			`elsif CLK'event and CLK = '1' then`
365			`ready_pb <= '0';`
366
367			`case state is`
368
369			`when IDLE =>`
370			`if start_pb = '1' then`
371			`first_rle_word <= '1';`
372			`state <= RUN_VLC;`
373			`end if;`
374
375			`when RUN_VLC =>`
376			`-- data valid DC or data valid AC`
377			`if (d_val_d2 = '1' and first_rle_word = '1') or`
378			`(d_val = '1' and first_rle_word = '0') then`
379			`for i in 0 to C_M-1 loop`
380			`if i < to_integer(VLC_size) then`
381			`word_reg(C_M-1-to_integer(bit_ptr)-i) <= VLC(to_integer(VLC_size)-1-i);`
382			`end if;`
383			`end loop;`
384			`bit_ptr <= bit_ptr + resize(VLC_size,bit_ptr'length);`
385
386			`-- HandleFifoWrites`
387			`HFW_running <= '1';`
388			`-- HandleFifoWrites completed`
389			`elsif HFW_running = '1' and`
390			`(num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then`
391			`-- shift word reg left to skip bytes already written to FIFO`
392			`word_reg <= shift_left(word_reg, to_integer(num_fifo_wrs & "000"));`
393			`-- adjust bit pointer after some bytes were written to FIFO`
394			`-- modulo 8 operation`
395			`bit_ptr <= bit_ptr - (num_fifo_wrs & "000");`
396			`HFW_running <= '0';`
397			`first_rle_word <= '0';`
398			`state <= RUN_VLI;`
399			`end if;`
400
401			`when RUN_VLI =>`
402			`if HFW_running = '0' then`
403
404			`for i in 0 to C_M-1 loop`
405			`if i < to_integer(VLI_ext_size) then`
406			`word_reg(C_M-1-to_integer(bit_ptr)-i)`
407			`<= VLI_ext(to_integer(VLI_ext_size)-1-i);`
408			`end if;`
409			`end loop;`
410
411			`bit_ptr <= bit_ptr + resize(VLI_ext_size,bit_ptr'length);`
412
413			`-- HandleFifoWrites`
414			`HFW_running <= '1';`
415			`-- HandleFifoWrites completed`
416			`elsif HFW_running = '1' and`
417			`(num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then`
418			`-- shift word reg left to skip bytes already written to FIFO`
419			`word_reg <= shift_left(word_reg, to_integer(num_fifo_wrs & "000"));`
420			`-- adjust bit pointer after some bytes were written to FIFO`
421			`-- modulo 8 operation`
422			`bit_ptr <= bit_ptr - (num_fifo_wrs & "000");`
423			`HFW_running <= '0';`
424
425			`-- end of block`
426			`if rle_fifo_empty = '1' then`
427			`-- end of segment`
428			`if bit_ptr - (num_fifo_wrs & "000") /= 0 and last_block = '1' then`
429			`state <= PAD;`
430			`else`
431			`ready_pb <= '1';`
432			`state <= IDLE;`
433			`end if;`
434			`else`
435			`state <= RUN_VLC;`
436			`end if;`
437			`end if;`
438
439			`-- end of segment which requires bit padding`
440			`when PAD =>`
441			`if HFW_running = '0' then`
442			`-- 1's bit padding to integer number of bytes`
443			`for i in 0 to 7 loop`
444			`if i < bit_ptr then`
445			`pad_byte(7-i) <= word_reg(C_M-1-i);`
446			`else`
447			`pad_byte(7-i) <= '1';`
448			`end if;`
449			`end loop;`
450			`pad_reg <= '1';`
451
452			`bit_ptr <= to_unsigned(8, bit_ptr'length);`
453
454			`-- HandleFifoWrites`
455			`HFW_running <= '1';`
456			`elsif HFW_running = '1' and`
457			`(num_fifo_wrs = 0 or fifo_wrt_cnt + 1 = num_fifo_wrs) then`
458			`bit_ptr <= (others => '0');`
459			`HFW_running <= '0';`
460			`pad_reg <= '0';`
461
462			`ready_pb <= '1';`
463			`state <= IDLE;`
464			`end if;`
465
466			`when others =>`
467
468			`end case;`
469
470			`if sof = '1' then`
471			`bit_ptr <= (others => '0');`
472			`end if;`
473
474			`end if;`
475			`end process;`
476
477
478			`end architecture RTL;`
479			`-------------------------------------------------------------------------------`
480			`-- Architecture: end`
481			`-------------------------------------------------------------------------------`