bsp3/Designflow/src/vga_control_arc.vhd

   1 -------------------------------------------------------------------------------
   2 -- Title      : vga_control architecture
   3 -- Project    : LU Digital Design
   4 -------------------------------------------------------------------------------
   5 -- File       : vga_control.vhd
   6 -- Author     : Thomas Handl
   7 -- Company    : TU Wien
   8 -- Created    : 2004-12-15
   9 -- Last update: 2006-02-24
  10 -------------------------------------------------------------------------------
  11 -- Description: generation of colors (RGB)
  12 -------------------------------------------------------------------------------
  13 -- Copyright (c) 2004 TU Wien
  14 -------------------------------------------------------------------------------
  15 -- Revisions  :
  16 -- Date        Version  Author  Description
  17 -- 2004-12-15  1.0      handl   Created
  18 -- 2006-02-24  2.0      ST      revised
  19 -------------------------------------------------------------------------------
  20
  21 -------------------------------------------------------------------------------
  22 -- LIBRARIES
  23 -------------------------------------------------------------------------------
  24
  25 library IEEE;
  26 use IEEE.std_logic_1164.all;
  27 use IEEE.std_logic_unsigned.all;
  28 use IEEE.std_logic_arith.all;
  29
  30 use work.vga_pak.all;
  31
  32 -------------------------------------------------------------------------------
  33 -- ARCHITECTURE
  34 -------------------------------------------------------------------------------
  35
  36 architecture behav of vga_control is
  37
  38
  39   attribute syn_preserve          : boolean;
  40   attribute syn_preserve of behav : architecture is true;
  41   signal   r_next, g_next, b_next  : std_logic;
  42
  43 begin
  44   DRAW_SQUARE_syn: process(clk, reset)
  45   begin
  46     if (reset = RES_ACT) then   -- draw black screen upon reset
  47       r <= COLR_OFF;
  48       g <= COLR_OFF;
  49       b <= COLR_OFF;
  50     elsif (clk'event and clk = '1') then     -- synchronous capture
  51       r <= r_next;
  52       g <= g_next;
  53       b <= b_next;
  54     end if;
  55   end process;
  56
  57
  58   DRAW_SQUARE_next: process (column_counter, v_enable, h_enable)
  59   begin
  60           if v_enable = ENABLE and h_enable = ENABLE then
  61                   if (column_counter >= X_MIN and column_counter < X2_MIN) then   -- if pixel within the rectangle borders
  62                           r_next <= COLR_OFF;
  63                           g_next <= COLR_OFF;
  64                           b_next <= COLR_ON;
  65                   elsif (column_counter >= X2_MIN and column_counter < X3_MIN) then   -- if pixel within the rectangle borders
  66                           r_next <= COLR_OFF;
  67                           g_next <= COLR_ON;
  68                           b_next <= COLR_ON;
  69                   elsif (column_counter >= X3_MIN and column_counter < X_MAX) then   -- if pixel within the rectangle borders
  70                           r_next <= COLR_ON;
  71                           g_next <= COLR_OFF;
  72                           b_next <= COLR_ON;
  73                   else                                                           -- if somewhere else on screen...
  74                           r_next <= COLR_OFF;
  75                           g_next <= COLR_OFF;                                          -- ... draw background color
  76                           b_next <= COLR_OFF;
  77                   end if;
  78           else                                                             -- if out of screen...
  79                   r_next <= COLR_OFF;
  80                   g_next <= COLR_OFF;                                            -- ... do not activate any color
  81                   b_next <= COLR_OFF;                                            --     (black screen)
  82           end if;
  83   end process;
  84
  85 end behav;
  86
  87 -------------------------------------------------------------------------------
  88 -- END ARCHITECTURE
  89 -------------------------------------------------------------------------------