Subversion Repositories mkjpeg

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-- File Name :  ZZ_TOP.vhd

--

-- Project   : JPEG_ENC

--

-- Module    : ZZ_TOP

--

-- Content   : ZigZag Top level

--

-- Description : Zig Zag scan

--

-- Spec.     :

--

-- Author    : Michal Krepa

--

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-- History :

-- 20090301: (MK): Initial Creation.

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----------------------------------- LIBRARY/PACKAGE ---------------------------

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-- generic packages/libraries:

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library ieee;

  use ieee.std_logic_1164.all;

  use ieee.numeric_std.all;

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-- user packages/libraries:

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library work;

  use work.JPEG_PKG.all;

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----------------------------------- ENTITY ------------------------------------

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entity ZZ_TOP is

  port

  (

        CLK                : in  std_logic;

        RST                : in  std_logic;

        -- CTRL

        start_pb           : in  std_logic;

        ready_pb           : out std_logic;

        zig_sm_settings    : in  T_SM_SETTINGS;

        -- Quantizer

        qua_buf_sel        : in  std_logic;

        qua_rdaddr         : in  std_logic_vector(5 downto 0);

        qua_data           : out std_logic_vector(11 downto 0);

        -- FDCT

        fdct_buf_sel       : out std_logic;

        fdct_rd_addr       : out std_logic_vector(5 downto 0);

        fdct_data          : in  std_logic_vector(11 downto 0);

        fdct_rden          : out std_logic

    );

end entity ZZ_TOP;

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----------------------------------- ARCHITECTURE ------------------------------

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architecture RTL of ZZ_TOP is

  signal dbuf_data      : std_logic_vector(11 downto 0);

  signal dbuf_q         : std_logic_vector(11 downto 0);

  signal dbuf_we        : std_logic;

  signal dbuf_waddr     : std_logic_vector(6 downto 0);

  signal dbuf_raddr     : std_logic_vector(6 downto 0);

  signal zigzag_di      : std_logic_vector(11 downto 0);

  signal zigzag_divalid : std_logic;

  signal zigzag_dout    : std_logic_vector(11 downto 0);

  signal zigzag_dovalid : std_logic;

  signal wr_cnt         : unsigned(5 downto 0);

  signal rd_cnt         : unsigned(5 downto 0);

  signal rd_en_d        : std_logic_vector(5 downto 0);

  signal rd_en          : std_logic;

  signal fdct_buf_sel_s : std_logic;

  signal zz_rd_addr     : std_logic_vector(5 downto 0);

  signal fifo_empty     : std_logic;

  signal fifo_rden      : std_logic;

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-- Architecture: begin

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begin

  fdct_rd_addr <= std_logic_vector(zz_rd_addr);

  qua_data     <= dbuf_q;

  fdct_buf_sel <= fdct_buf_sel_s;

  fdct_rden    <= rd_en;

  -------------------------------------------------------------------

  -- ZigZag Core

  -------------------------------------------------------------------

  U_zigzag : entity work.zigzag

  generic map

    (

      RAMADDR_W     => 6,

      RAMDATA_W     => 12

    )

  port map

    (

      rst        => RST,

      clk        => CLK,

      di         => zigzag_di,

      divalid    => zigzag_divalid,

      rd_addr    => rd_cnt,

      fifo_rden  => fifo_rden,

      fifo_empty => fifo_empty,

      dout       => zigzag_dout,

      dovalid    => zigzag_dovalid,

      zz_rd_addr => zz_rd_addr

    );

  zigzag_di      <= fdct_data;

  zigzag_divalid <= rd_en_d(1);

  -------------------------------------------------------------------

  -- DBUF

  -------------------------------------------------------------------

  U_RAMZ : entity work.RAMZ

  generic map

  (

      RAMADDR_W     => 7,

      RAMDATA_W     => 12

  )

  port map

  (

        d           => dbuf_data,

        waddr       => dbuf_waddr,

        raddr       => dbuf_raddr,

        we          => dbuf_we,

        clk         => CLK,

        q           => dbuf_q

  );

  dbuf_data  <= zigzag_dout;

  dbuf_waddr <= (not qua_buf_sel) & std_logic_vector(wr_cnt);

  dbuf_we    <= zigzag_dovalid;

  dbuf_raddr <= qua_buf_sel & qua_rdaddr;

  -------------------------------------------------------------------

  -- FIFO Ctrl

  -------------------------------------------------------------------

  p_fifo_ctrl : process(CLK, RST)

  begin

    if RST = '1' then

      fifo_rden   <= '0';

    elsif CLK'event and CLK = '1' then

      if fifo_empty = '0' then

        fifo_rden <= '1';

      else

        fifo_rden <= '0';

      end if;

    end if;

  end process;

  -------------------------------------------------------------------

  -- Counter1

  -------------------------------------------------------------------

  p_counter1 : process(CLK, RST)

  begin

    if RST = '1' then

      rd_en        <= '0';

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

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

    elsif CLK'event and CLK = '1' then

      rd_en_d <= rd_en_d(rd_en_d'length-2 downto 0) & rd_en;

      if start_pb = '1' then

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

        rd_en <= '1';

      end if;

      if rd_en = '1' then

        if rd_cnt = 64-1 then

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

          rd_en  <= '0';

        else

          rd_cnt <= rd_cnt + 1;

        end if;

      end if;

    end if;

  end process;

  -------------------------------------------------------------------

  -- wr_cnt

  -------------------------------------------------------------------

  p_wr_cnt : process(CLK, RST)

  begin

    if RST = '1' then

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

      ready_pb <= '0';

    elsif CLK'event and CLK = '1' then

      ready_pb <= '0';

      if start_pb = '1' then

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

      end if;

      if zigzag_dovalid = '1' then

        if wr_cnt = 64-1 then

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

        else

          wr_cnt <=wr_cnt + 1;

        end if;

        -- give ready ahead to save cycles!

        if wr_cnt = 64-1-3 then

          ready_pb <= '1';

        end if;

      end if;

    end if;

  end process;

  -------------------------------------------------------------------

  -- fdct_buf_sel

  -------------------------------------------------------------------

  p_buf_sel : process(CLK, RST)

  begin

    if RST = '1' then

      fdct_buf_sel_s   <= '0';

    elsif CLK'event and CLK = '1' then

      if start_pb = '1' then

        fdct_buf_sel_s <= not fdct_buf_sel_s;

      end if;

    end if;

  end process;

end architecture RTL;

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-- Architecture: end

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