Subversion Repositories yavga

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----                                                                        ----
---- This file is part of the yaVGA project                                 ----
---- http://www.opencores.org/?do=project&who=yavga                         ----
----                                                                        ----
---- Description                                                            ----
---- Implementation of yaVGA IP core                                        ----
----                                                                        ----
---- To Do:                                                                 ----
----                                                                        ----
----                                                                        ----
---- Author(s):                                                             ----
---- Sandro Amato, sdroamt@netscape.net                                     ----
----                                                                        ----
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----                                                                        ----
---- Copyright (c) 2009, Sandro Amato                                       ----
---- All rights reserved.                                                   ----
----                                                                        ----
---- Redistribution  and  use in  source  and binary forms, with or without ----
---- modification,  are  permitted  provided that  the following conditions ----
---- are met:                                                               ----
----                                                                        ----
----     * Redistributions  of  source  code  must  retain the above        ----
----       copyright   notice,  this  list  of  conditions  and  the        ----
----       following disclaimer.                                            ----
----     * Redistributions  in  binary form must reproduce the above        ----
----       copyright   notice,  this  list  of  conditions  and  the        ----
----       following  disclaimer in  the documentation and/or  other        ----
----       materials provided with the distribution.                        ----
----     * Neither  the  name  of  SANDRO AMATO nor the names of its        ----
----       contributors may be used to  endorse or  promote products        ----
----       derived from this software without specific prior written        ----
----       permission.                                                      ----
----                                                                        ----
---- THIS SOFTWARE IS PROVIDED  BY THE COPYRIGHT  HOLDERS AND  CONTRIBUTORS ----
---- "AS IS"  AND  ANY EXPRESS OR  IMPLIED  WARRANTIES, INCLUDING,  BUT NOT ----
---- LIMITED  TO, THE  IMPLIED  WARRANTIES  OF MERCHANTABILITY  AND FITNESS ----
---- FOR  A PARTICULAR  PURPOSE  ARE  DISCLAIMED. IN  NO  EVENT  SHALL  THE ----
---- COPYRIGHT  OWNER  OR CONTRIBUTORS  BE LIABLE FOR ANY DIRECT, INDIRECT, ----
---- INCIDENTAL,  SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, ----
---- BUT  NOT LIMITED  TO,  PROCUREMENT OF  SUBSTITUTE  GOODS  OR SERVICES; ----
---- LOSS  OF  USE,  DATA,  OR PROFITS;  OR  BUSINESS INTERRUPTION) HOWEVER ----
---- CAUSED  AND  ON  ANY THEORY  OF LIABILITY, WHETHER IN CONTRACT, STRICT ----
---- LIABILITY,  OR  TORT  (INCLUDING  NEGLIGENCE  OR OTHERWISE) ARISING IN ----
---- ANY  WAY OUT  OF THE  USE  OF  THIS  SOFTWARE,  EVEN IF ADVISED OF THE ----
---- POSSIBILITY OF SUCH DAMAGE.                                            ----
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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 instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;
 
entity s3e_starter_1600k is
  port (i_clk    : in  std_logic;
         o_hsync : out std_logic;
         o_vsync : out std_logic;
         o_r     : out std_logic;
         o_g     : out std_logic;
         o_b     : out std_logic);
end s3e_starter_1600k;
 
architecture Behavioral of s3e_starter_1600k is
 
  component vga_ctrl
    port(
      i_clk          : in  std_logic;
      i_reset        : in  std_logic;
      i_background   : in  std_logic;
      i_cursor_color : in  std_logic_vector(2 downto 0);
      i_cursor_x     : in  std_logic_vector(10 downto 0);
      i_cursor_y     : in  std_logic_vector(9 downto 0);
      i_h_sync_en    : in  std_logic;
      i_v_sync_en    : in  std_logic;
      i_chr_addr     : in  std_logic_vector(10 downto 0);
      i_chr_data     : in  std_logic_vector(31 downto 0);
      i_chr_clk      : in  std_logic;
      i_chr_en       : in  std_logic;
      i_chr_we       : in  std_logic_vector(3 downto 0);
      i_chr_rst      : in  std_logic;
      i_wav_d        : in  std_logic_vector(15 downto 0);
      i_wav_we       : in  std_logic;
      i_wav_addr     : in  std_logic_vector(9 downto 0);
      o_h_sync       : out std_logic;
      o_v_sync       : out std_logic;
      o_r            : out std_logic;
      o_g            : out std_logic;
      o_b            : out std_logic;
      o_chr_data     : out std_logic_vector(31 downto 0)
      );
  end component;
 
  signal s_hsync : std_logic;
  signal s_vsync : std_logic;
  signal s_r     : std_logic;
  signal s_g     : std_logic;
  signal s_b     : std_logic;
 
  signal s_vsync_count : std_logic_vector(7 downto 0) := (others => '0');
  signal s_vsync1      : std_logic;
 
  signal s_chr_addr : std_logic_vector(10 downto 0) := (others => '0');
  signal s_rnd      : std_logic_vector(31 downto 0) := (others => '0');
  signal s_chr_we   : std_logic_vector(3 downto 0);
 
  attribute U_SET                      : string;
  attribute U_SET of "u1_vga_ctrl"    : label is "u1_vga_ctrl_uset";
 
begin
  o_hsync <= s_hsync;
  o_vsync <= s_vsync;
  o_r     <= s_r;
  o_g     <= s_g;
  o_b     <= s_b;
 
  u1_vga_ctrl : vga_ctrl port map(
    i_clk          => i_clk,
    i_reset        => '0',
    i_background   => '0',
    i_cursor_color => "001",
    i_cursor_x     => "00101000000",
    i_cursor_y     => "0011000000",
    o_h_sync       => s_hsync,
    o_v_sync       => s_vsync,
    i_h_sync_en    => '1',
    i_v_sync_en    => '1',
    o_r            => s_r,
    o_g            => s_g,
    o_b            => s_b,
    i_chr_addr     => s_chr_addr,       --B"000_0000_0000",
    i_chr_data     => s_rnd,            --X"00000000",
    o_chr_data     => open,
    i_chr_clk      => i_clk,
    i_chr_en       => '1',
    i_chr_we       => s_chr_we,
    i_chr_rst      => '0',
    i_wav_d        => X"0000",  --s_rnd(15 downto 0), -- 
    i_wav_we       => '0',  --s_chr_we(0), --
    i_wav_addr     => B"00_0000_0000"  --s_chr_addr(9 downto 0) --
    );
 
  p_write_chars : process(i_clk)
  begin
    if rising_edge(i_clk) then
      -- during the sync time in order to avoid flickering
      -- and each 128 vsync in order to stop for a while
      -- will write random chars...
      if s_vsync_count(7) = '1' and (s_hsync = '0' or s_vsync = '0') then
        -- generate a pseudo random 32 bit number
        s_rnd <= s_rnd(30 downto 0) & (s_rnd(31) xnor s_rnd(21) xnor s_rnd(1) xnor s_rnd(0));
        -- increment the address and write enable...
        s_chr_addr <= s_chr_addr + 1;
        s_chr_we   <= "1111";
      else
        s_chr_addr <= s_chr_addr;
        s_chr_we   <= "0000";
        s_rnd      <= s_rnd;
      end if;
    end if;
  end process;
 
--  p_rnd_bit : process(i_clk)
--    variable v_rnd_fb : std_logic;
--    variable v_rnd : std_logic_vector(31 downto 0);
--  begin
--    if rising_edge(i_clk) then
--      s_rnd_bit <= v_rnd_fb;
--      v_rnd_fb := v_rnd(31) xnor v_rnd(21) xnor v_rnd(1) xnor v_rnd(0);
--      v_rnd    := v_rnd(30 downto 0) & v_rnd_fb;
--    end if;
--  end process;
 
  p_vsync_count : process(i_clk)
  begin
    if rising_edge(i_clk) then
      s_vsync1 <= s_vsync;
      if (not s_vsync and s_vsync1) = '1' then  -- pulse on vsync falling
        s_vsync_count <= s_vsync_count + 1;
      end if;
    end if;
  end process;
 
 
 
end Behavioral;