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;

use work.yavga_pkg.all;

---- Uncomment the following library declaration if instantiating

---- any Xilinx primitives in this code.

--library UNISIM;

--use UNISIM.VComponents.all;

entity vga_ctrl is

--      generic (

--              g_H_SIZE : integer := 800;      -- horizontal size of input image, MAX 800

--              g_V_SIZE : integer := 600       -- vertical size of input image, MAX 600

--      );

  port (

    i_clk   : in std_logic;             -- must be 50MHz

    i_reset : in std_logic;

    -- vga horizontal and vertical sync

    o_h_sync : out std_logic;

    o_v_sync : out std_logic;

    -- horizontal and vertical sync enable (allow power saving on ?VESA? Monitors)

    i_h_sync_en : in std_logic;

    i_v_sync_en : in std_logic;

    -- vga R G B signals (1 bit for each component (8 colors))

    o_r : out std_logic;

    o_g : out std_logic;

    o_b : out std_logic;

    -- chars RAM memory

    i_chr_addr : in  std_logic_vector(c_CHR_ADDR_BUS_W - 1 downto 0);

    i_chr_data : in  std_logic_vector(c_CHR_DATA_BUS_W - 1 downto 0);

    o_chr_data : out std_logic_vector(c_CHR_DATA_BUS_W - 1 downto 0);

    i_chr_clk  : in  std_logic;

    i_chr_en   : in  std_logic;

    i_chr_we   : in  std_logic_vector(c_CHR_WE_BUS_W - 1 downto 0);

    i_chr_rst  : in  std_logic;

    -- waveform RAM memory

    i_wav_d    : in std_logic_vector(c_WAVFRM_DATA_BUS_W - 1 downto 0);

    i_wav_we   : in std_logic;

    i_wav_clk  : in std_logic;

    i_wav_addr : in std_logic_vector(c_WAVFRM_ADDR_BUS_W - 1 downto 0)  --;

    --o_DOA : OUT std_logic_vector(15 downto 0)

    );

end vga_ctrl;

-- vga timings used

--                     0                                    TOT

-- ...-----------------|=============== PERIOD ==============|--...

--                     |                                     |

-- ...__           ___________________________           _______...

--      \_________/                           \_________/

--                                                                 

--      |         |    |               |      |         |    |

--      |         |    |               |      |         |    |

-- ...--|----S----|-F--|=======D=======|==B===|====S====|=F==|--...

--           Y      R          I          A        Y      R

--           N      O          S          C        N      O

--           C      N          P          K        C      N

--           T      T          L          P        T      T

--           I      P          T          O        I      P

--           M      O          I          R        M      O

--           E      R          M          C        E      R

--                  C          E          H               C

--                  H                                     H

--      |         |    |               |      |         |    |

--   ...|---------|----|===============|======|=========|====|--...

-- HPx:     120     56         800        63      120     56    px (h PERIOD = 1039 px)

-- VLn:     6       37         600        23      6       37    ln (v PERIOD = 666 ln)

--

-- and with 50Mhz dot clock (20ns dot time):

--      |         |    |               |      |         |    |

--   ...|---------|----|===============|======|=========|====|--...

--Htime:   2.4     1.12        16        1.26     2.4    1.12   usec  (h PERIOD = 20.78 usec) Hfreq 48123.195 Hz

--Vtime:  124.68  768.86     12468      477.94  124.68  768.68  usec  (v PERIOD = 13839.48 usec) Vfreq 72.257 Hz

architecture rtl of vga_ctrl is

  --

  signal s_h_count      : std_logic_vector(c_H_COUNT_W - 1 downto 0);  -- horizontal pixel counter

  signal s_v_count      : std_logic_vector(c_V_COUNT_W - 1 downto 0);  -- verticalal line counter

  signal s_v_count_d_4  : std_logic_vector(3 downto 0);  -- verticalal line counter mod 16 (char height)

  signal s_h_sync       : std_logic;    -- horizontal sync trigger

  signal s_h_sync_pulse : std_logic;    -- 1-clock pulse on sync trigger

  --

  -- signals for the charmaps Block RAM component...

  signal s_charmaps_en   : std_logic;

  signal s_charmaps_ADDR : std_logic_vector (c_INTCHMAP_ADDR_BUS_W - 1 downto 0);

  signal s_charmaps_DO   : std_logic_vector (c_INTCHMAP_DATA_BUS_W - 1 downto 0);

  --

  -- to manage the outside display region's blanking

  signal s_display : std_logic;

  --

  --

  -- to manage the chars  ram address and the ram ascii

  signal s_chars_ram_addr : std_logic_vector(c_INTCHR_ADDR_BUS_W - 1 downto 0);

  signal s_chars_ascii    : std_logic_vector(c_INTCHR_DATA_BUS_W - 1 downto 0);

  signal s_chars_EN_r     : std_logic;

  -- to manage the waveform ram address and data

  signal s_waveform_ADDRB : std_logic_vector (c_WAVFRM_ADDR_BUS_W - 1 downto 0);

  signal s_waveform_DOB   : std_logic_vector (c_WAVFRM_DATA_BUS_W - 1 downto 0);

  -- charmaps

  -- |------| |-----------------|

  -- |   P  | | D D D D D D D D |

  -- |======| |=================|

  -- |   8  | | 7 6 5 4 3 2 1 0 |

  -- |======| |=================|

  -- | Free | | Row char pixels |

  -- |------| |-----------------|

  --

  component charmaps_rom

    port(

      i_EN    : in  std_logic;

      i_clock : in  std_logic;

      i_ADDR  : in  std_logic_vector(c_INTCHMAP_ADDR_BUS_W - 1 downto 0);  -- 16 x ascii code (W=8 x H=16 pixel)

      o_DO    : out std_logic_vector(c_INTCHMAP_DATA_BUS_W - 1 downto 0)  -- 8 bit char pixel

      );

  end component;

  -- wave form or video-line memory

  -- |------| |-------------------------------------------|

  -- | P  P | |  D  D  D |  D  D  D | D D D D D D D D D D |

  -- |======| |===========================================|

  -- |17 16 | | 15 14 13 | 12 11 10 | 9 8 7 6 5 4 3 2 1 0 |

  -- |======| |===========================================|

  -- | Free | |  Reserv. |  R  G  B |      vert. pos.     |

  -- |------| |-------------------------------------------|

  --

  component waveform_ram

    port(

      i_DIA    : in  std_logic_vector(c_WAVFRM_DATA_BUS_W - 1 downto 0);

      i_WEA    : in  std_logic;

      i_clockA : in  std_logic;

      i_ADDRA  : in  std_logic_vector(c_WAVFRM_ADDR_BUS_W - 1 downto 0);

      --o_DOA : OUT std_logic_vector(15 downto 0);

      --

      i_DIB    : in  std_logic_vector(c_WAVFRM_DATA_BUS_W - 1 downto 0);

      i_WEB    : in  std_logic;

      i_clockB : in  std_logic;

      i_ADDRB  : in  std_logic_vector(c_WAVFRM_ADDR_BUS_W - 1 downto 0);

      o_DOB    : out std_logic_vector(c_WAVFRM_DATA_BUS_W - 1 downto 0)

      );

  end component;

  component chars_RAM

    port(

      i_clock_rw : in  std_logic;

      i_EN_rw    : in  std_logic;

      i_WE_rw    : in  std_logic_vector(c_CHR_WE_BUS_W - 1 downto 0);

      i_ADDR_rw  : in  std_logic_vector(c_CHR_ADDR_BUS_W - 1 downto 0);

      i_DI_rw    : in  std_logic_vector(c_CHR_DATA_BUS_W - 1 downto 0);

      o_DI_rw    : out std_logic_vector(c_CHR_DATA_BUS_W - 1 downto 0);

      i_SSR      : in  std_logic;

      i_clock_r  : in  std_logic;

      i_EN_r     : in  std_logic;

      i_ADDR_r   : in  std_logic_vector(c_INTCHR_ADDR_BUS_W - 1 downto 0);

      o_DO_r     : out std_logic_vector(c_INTCHR_DATA_BUS_W - 1 downto 0)

      );

  end component;

  attribute U_SET                      : string;

  attribute U_SET of "u0_chars_RAM"    : label is "u0_chars_RAM_uset";

  attribute U_SET of "u1_charmaps_rom" : label is "u1_charmaps_rom_uset";

  attribute U_SET of "u2_waveform_ram" : label is "u2_waveform_ram_uset";

  -- to read some configuration params from the char ram

  signal s_config_time  : std_logic;

  --

  -- to manage the background and cursor colors

  signal s_cursor_color : std_logic_vector(2 downto 0) := "000";

  signal s_bg_color     : std_logic_vector(2 downto 0) := "000";

  --

  -- to manage the cursor position  

  signal s_cursor_x     : std_logic_vector(c_H_COUNT_W - 1 downto 0);

  signal s_cursor_y     : std_logic_vector(c_V_COUNT_W - 1 downto 0);

  function f_is_cursor_pixel(

    s_h, s_v, s_cur_x, s_cur_y : std_logic_vector)

    return boolean is

  begin

    return ((s_h = s_cur_x) or (s_v = s_cur_y));

  end f_is_cursor_pixel;

  function f_is_grid_pixel(

    s_h, s_v : std_logic_vector)

    return boolean is

  begin

    return (

      (s_h(c_GRID_BIT downto 0) = c_GRID_SIZE(c_GRID_BIT downto 0)) or

      (s_v(c_GRID_BIT downto 0) = c_GRID_SIZE(c_GRID_BIT downto 0))

      );

  end f_is_grid_pixel;

  function f_is_waveform_pixel(

    s_v, s_wav, s_wav_prev : std_logic_vector)

    return boolean is

  begin

    return (

      ((s_v >= s_wav) and (s_v <= s_wav_prev)) or

      ((s_v                    <= s_wav) and (s_v >= s_wav_prev))

      );

  end f_is_waveform_pixel;

begin

  -- read config params from ram...

  p_config : process(i_clk)

  begin

    if rising_edge(i_clk) then

      case s_chars_ram_addr is

        when c_CFG_BG_CUR_COLOR_ADDR =>  -- bg and curs color are on the same byte byte

          s_config_time  <= '1';

          s_cursor_color <= s_chars_ascii(2 downto 0);

          s_bg_color     <= s_chars_ascii(5 downto 3);

        when c_CFG_CURS_XY1 =>          -- xy coords spans on three bytes 

          s_config_time           <= '1';

          s_cursor_x(10 downto 6) <= s_chars_ascii(4 downto 0);

        when c_CFG_CURS_XY2 =>          -- xy coords spans on three bytes

          s_config_time          <= '1';

          s_cursor_x(5 downto 0) <= s_chars_ascii(7 downto 2);

          s_cursor_y(9 downto 8) <= s_chars_ascii(1 downto 0);

        when c_CFG_CURS_XY3 =>          -- xy coords spans on three bytes

          s_config_time          <= '1';

          s_cursor_y(7 downto 0) <= s_chars_ascii(7 downto 0);

        when others =>

          s_config_time <= '0';

      end case;

    end if;

  end process;

  -- enable the ram both

  --   - during the display time

  --   - to read configuration params

  s_chars_EN_r <= s_display or s_config_time;

  -- modify the chars_ram address

  s_chars_ram_addr <= s_v_count(9 downto 4) & s_h_count(9 downto 3);

  u0_chars_RAM : chars_RAM port map(

    i_clock_rw => i_chr_clk,

    i_EN_rw    => i_chr_en,

    i_WE_rw    => i_chr_we,

    i_ADDR_rw  => i_chr_addr,

    i_DI_rw    => i_chr_data,

    o_DI_rw    => o_chr_data,

    i_SSR      => i_chr_rst,

    i_clock_r  => not i_clk,

    i_EN_r     => s_chars_EN_r,

    i_ADDR_r   => s_chars_ram_addr,

    o_DO_r     => s_chars_ascii

    );

  -- modify the charmaps address (each 16 s_v_count - chars are 16 pixel tall)

  --                  v----- ascii code ------v    v-- vert px mod 16 --v (chars are 16 pixel tall)

  --s_charmaps_ADDR <= (s_chars_ascii(6 downto 0) & s_v_count(3 downto 0));

  s_charmaps_ADDR <= (s_chars_ascii(6 downto 0) & s_v_count_d_4);

  s_charmaps_en   <=

    '1' when s_h_count(2 downto 0) = "111"  -- each 8 h_count (chars are 8 pixel wide)

    else '0';

  u1_charmaps_rom : charmaps_rom port map(

    i_en    => s_charmaps_en,

    i_clock => not i_clk,

    i_ADDR  => s_charmaps_ADDR,

    o_DO    => s_charmaps_DO

    );

  -- modify the waveform address

  s_waveform_ADDRB <= s_h_count(9 downto 0);

  u2_waveform_ram : waveform_ram port map(

    i_DIA    => i_wav_d,

    i_WEA    => i_wav_we,

    i_clockA => i_wav_clk,

    i_ADDRA  => i_wav_addr,

    --o_DOA => o_DOA,

    --

    i_DIB    => "1111111111111111",

    i_WEB    => '0',

    i_clockB => not i_clk,

    i_ADDRB  => s_waveform_ADDRB,

    o_DOB    => s_waveform_DOB

    );

  -- generate a single clock pulse on hsync falling

  p_pulse_on_hsync_falling : process(i_clk)

    variable v_h_sync1 : std_logic;

  begin

    if rising_edge(i_clk) then

      s_h_sync_pulse <= not s_h_sync and v_h_sync1;

      v_h_sync1      := s_h_sync;

    end if;

  end process;

  -- control the reset, increment and overflow of the horizontal pixel count

  p_H_PX_COUNT : process(i_clk)                          --, i_reset)

  begin

    if rising_edge(i_clk) then

      if i_reset = '1' or s_h_count = c_H_PERIODpx then  -- sync reset

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

      else

        s_h_count <= s_h_count + 1;

      end if;

    end if;

  end process;

  -- control the reset, increment and overflow of the vertical pixel count

  p_V_LN_COUNT : process(i_clk)

  begin

    if rising_edge(i_clk) then

      if i_reset = '1' or s_v_count = c_V_PERIODln then  -- sync reset

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

        s_v_count_d_4 <= s_v_count(3 downto 0);

      elsif s_h_sync_pulse = '1' then

        s_v_count     <= s_v_count + 1;

        s_v_count_d_4 <= s_v_count(3 downto 0);

      end if;

    end if;

  end process;

  -- set the horizontal sync high time and low time according to the constants

  p_MGM_H_SYNC : process(i_clk)         --, i_reset)

  begin

    if rising_edge(i_clk) then

      if (s_h_count = c_H_DISPLAYpx + c_H_BACKPORCHpx) then

        s_h_sync <= '0';

      elsif (s_h_count = c_H_PERIODpx - c_H_FRONTPORCHpx) then

        s_h_sync <= '1';

      end if;

    end if;

  end process;

  o_h_sync <= s_h_sync and i_h_sync_en;

  -- set the vertical sync high time and low time according to the constants

  p_MGM_V_SYNC : process(i_clk)         --, i_reset)

  begin

    --if falling_edge(i_clk) then

    if rising_edge(i_clk) then

      if i_v_sync_en = '0' or

        (s_v_count = (c_V_DISPLAYln + c_V_BACKPORCHln)) then

        o_v_sync <= '0';

      elsif (s_v_count = (c_V_PERIODln - c_V_FRONTPORCHln)) then  --and (s_h_sync_pulse = '1') then

        o_v_sync <= '1';

      end if;

    end if;

  end process;

  -- asserts the blaking signal (active low)

  p_MGM_BLANK : process (i_clk)         --, i_reset)

  begin

    if rising_edge(i_clk) then

      -- if we are outside the visible range on the screen then tell the RAMDAC to blank

      -- in this section by putting s_display low

      if not (s_h_count < c_H_DISPLAYpx and s_v_count < c_V_DISPLAYln) then

        s_display <= '0';

      else

        s_display <= '1';

      end if;

    end if;

  end process;

  -- generates the r g b signals showing chars, grid and "cross cursor"

  p_MGM_RGB : process (i_clk)

    variable v_previous_pixel : std_logic_vector(9 downto 0) := "0100101100";

  begin

    if rising_edge(i_clk) then          -- not async reset

      if i_reset = '1' then             -- sync reset

        o_r <= '0';

        o_g <= '0';

        o_b <= '0';

      else

        if s_display = '1' then         -- display zone

          if (

            f_is_cursor_pixel(s_h_count, s_v_count, s_cursor_x, s_cursor_y) or

            f_is_grid_pixel(s_h_count, s_v_count)

            ) and (s_v_count(9) = '0')  -- < 512

          then  -- draw the cursor and/or WaveForm Grid references

            o_r <= s_cursor_color(2);

            o_g <= s_cursor_color(1);

            o_b <= s_cursor_color(0);

          elsif

            f_is_waveform_pixel(s_v_count, s_waveform_DOB(c_V_COUNT_W - 1 downto 0), v_previous_pixel)

          then                          -- draw the waveform pixel...

            o_r <= s_waveform_DOB(12) or s_waveform_DOB(15);  -- the "or" is only

            o_g <= s_waveform_DOB(11) or s_waveform_DOB(14);  -- to not warning

            o_b <= s_waveform_DOB(10) or s_waveform_DOB(13);  -- unused signals

          else                          -- draw the background and charmaps

            case (s_h_count(2 downto 0)) is

              when "000"  => o_g <= s_charmaps_DO(7) xor s_bg_color(1);

              when "001"  => o_g <= s_charmaps_DO(6) xor s_bg_color(1);

              when "010"  => o_g <= s_charmaps_DO(5) xor s_bg_color(1);

              when "011"  => o_g <= s_charmaps_DO(4) xor s_bg_color(1);

              when "100"  => o_g <= s_charmaps_DO(3) xor s_bg_color(1);

              when "101"  => o_g <= s_charmaps_DO(2) xor s_bg_color(1);

              when "110"  => o_g <= s_charmaps_DO(1) xor s_bg_color(1);

              when "111"  => o_g <= s_charmaps_DO(0) xor s_bg_color(1);

              when others => o_g <= 'X';

            end case;

            o_r <= s_bg_color(2);

            --o_g <= s_bg_color(1);

            o_b <= s_bg_color(0);

          end if;

        else                            -- blank zone

          -- the blanking zone

          o_r <= '0';

          o_g <= '0';

          o_b <= '0';

        end if;  -- if s_display

        v_previous_pixel := s_waveform_DOB(9 downto 0);

      end if;  -- if i_reset

    end if;  -- if rising_edge(i_clk)

  end process;

end rtl;