--- /dev/null
+-------------------------------------------------------------------------------\r
+-- Title : vga_control architecture\r
+-- Project : LU Digital Design\r
+-------------------------------------------------------------------------------\r
+-- File : vga_control.vhd\r
+-- Author : Thomas Handl\r
+-- Company : TU Wien\r
+-- Created : 2004-12-15\r
+-- Last update: 2006-02-24\r
+-------------------------------------------------------------------------------\r
+-- Description: generation of colors (RGB)\r
+-------------------------------------------------------------------------------\r
+-- Copyright (c) 2004 TU Wien\r
+-------------------------------------------------------------------------------\r
+-- Revisions :\r
+-- Date Version Author Description\r
+-- 2004-12-15 1.0 handl Created\r
+-- 2006-02-24 2.0 ST revised\r
+-------------------------------------------------------------------------------\r
+\r
+-------------------------------------------------------------------------------\r
+-- LIBRARIES\r
+-------------------------------------------------------------------------------\r
+\r
+library IEEE;\r
+use IEEE.std_logic_1164.all;\r
+use IEEE.std_logic_unsigned.all;\r
+use IEEE.std_logic_arith.all;\r
+\r
+use work.vga_pak.all;\r
+\r
+-------------------------------------------------------------------------------\r
+-- ARCHITECTURE\r
+-------------------------------------------------------------------------------\r
+\r
+architecture behav of vga_control is\r
+\r
+\r
+ attribute syn_preserve : boolean;\r
+ attribute syn_preserve of behav : architecture is true;\r
+\r
+\r
+ -- signal and constant declarations \r
+ signal r_next, g_next, b_next : std_logic; -- auxiliary signals for next state logic\r
+ signal toggle_sig : std_logic; -- auxiliary signal to allow read back of toggle\r
+ signal toggle_counter_sig : std_logic_vector(TOG_CNT_WIDTH-1 downto 0); -- auxiliary signal to allow read back of blinker\r
+ signal toggle_next : std_logic; -- auxiliary signal for next state logic\r
+ signal toggle_counter_next : std_logic_vector(TOG_CNT_WIDTH-1 downto 0); -- auxiliary signal for next state logic\r
+ --constant HALFPERIOD : std_logic_vector(TOG_CNT_WIDTH-1 downto 0) := "1100000000010001111011000";\r
+ constant HALFPERIOD : std_logic_vector(TOG_CNT_WIDTH-1 downto 0) := "0000011111110010100000010"; -- 41,6666ms\r
+ --constant HALFPERIOD : std_logic_vector(TOG_CNT_WIDTH-1 downto 0) := "0000101101110001101100000"; --60ms\r
+ -- define half period of toggle frequency in clock ticks\r
+\r
+begin \r
+ -----------------------------------------------------------------------------\r
+ -- draw rectangle on screen\r
+ -----------------------------------------------------------------------------\r
+ \r
+ DRAW_SQUARE_syn: process(clk, reset)\r
+ begin\r
+ if (reset = RES_ACT) then -- draw black screen upon reset\r
+ r <= COLR_OFF;\r
+ g <= COLR_OFF;\r
+ b <= COLR_OFF;\r
+ elsif (clk'event and clk = '1') then -- synchronous capture\r
+ r <= r_next;\r
+ g <= g_next;\r
+ b <= b_next;\r
+ end if;\r
+ end process;\r
+\r
+\r
+ DRAW_SQUARE_next: process (column_counter, line_counter, v_enable, h_enable, toggle_sig)\r
+ begin\r
+ if v_enable = ENABLE and h_enable = ENABLE then \r
+ if (column_counter >= X_MIN and column_counter <= X_MAX and -- if pixel within the rectangle borders\r
+ line_counter >= Y_MIN and line_counter <= Y_MAX) then\r
+ r_next <= COLR_OFF;\r
+ g_next <= COLR_OFF; -- ...green\r
+ b_next <= toggle_sig; -- ...blue\r
+ else -- if somewhere else on screen...\r
+ r_next <= COLR_OFF;\r
+ g_next <= COLR_OFF; -- ... draw background color\r
+ b_next <= COLR_OFF;\r
+ end if;\r
+ else -- if out of screen...\r
+ r_next <= COLR_OFF;\r
+ g_next <= COLR_OFF; -- ... do not activate any color\r
+ b_next <= COLR_OFF; -- (black screen)\r
+ end if;\r
+ end process;\r
+\r
+\r
+ -----------------------------------------------------------------------------\r
+ -- control blinking of rectangle\r
+ -----------------------------------------------------------------------------\r
+\r
+ BLINKER_syn: process(clk, reset)\r
+ begin\r
+ if (reset = RES_ACT) then -- asyn reset\r
+ toggle_counter_sig <= (others => '0');\r
+ toggle_sig <= COLR_OFF;\r
+ elsif(clk'event and clk = '1') then -- synchronous capture\r
+ toggle_counter_sig <= toggle_counter_next;\r
+ toggle_sig <= toggle_next;\r
+ end if;\r
+ end process;\r
+\r
+\r
+ BLINKER_next : process(toggle_counter_sig, toggle_sig)\r
+ begin\r
+ if toggle_counter_sig >= HALFPERIOD then -- after half period ...\r
+ toggle_counter_next <= (others => '0'); -- ... clear counter\r
+ toggle_next <= not(toggle_sig); -- ... and toggle colour.\r
+ else -- before half period ...\r
+ toggle_counter_next <= toggle_counter_sig + '1'; -- ... increment counter\r
+ toggle_next <= toggle_sig; -- ... and hold colour\r
+ end if;\r
+ end process;\r
+\r
+\r
+-- assign auxiliary signals to module outputs\r
+toggle <= toggle_sig;\r
+toggle_counter <= toggle_counter_sig;\r
+\r
+end behav;\r
+\r
+-------------------------------------------------------------------------------\r
+-- END ARCHITECTURE\r
+-------------------------------------------------------------------------------\r
projects / dide_16.git / blobdiff