library IEEE; use IEEE.STD_LOGIC_1164.all; use IEEE.STD_LOGIC_ARITH.all; use IEEE.STD_LOGIC_UNSIGNED.all; ENTITY VGA_SYNC IS PORT( clock_25Mhz, red, green, blue : IN STD_LOGIC; red_out, green_out, blue_out, horiz_sync_out, vert_sync_out : OUT STD_LOGIC; pixel_row, pixel_column: OUT STD_LOGIC_VECTOR(9 DOWNTO 0); newframe : out STD_LOGIC; newline : out STD_LOGIC); END VGA_SYNC; ARCHITECTURE a OF VGA_SYNC IS SIGNAL horiz_sync, vert_sync : STD_LOGIC; SIGNAL video_on, video_on_v, video_on_h : STD_LOGIC; SIGNAL h_count, v_count :STD_LOGIC_VECTOR(9 DOWNTO 0); BEGIN -- video_on is high only when RGB data is displayed video_on <= video_on_H AND video_on_V; PROCESS BEGIN WAIT UNTIL(clock_25Mhz'EVENT) AND (clock_25Mhz='1'); --Generate Horizontal and Vertical Timing Signals for Video Signal -- H_count counts pixels (640 + extra time for sync signals) -- -- Horiz_sync ------------------------------------__________-------- -- H_count 0 640 659 755 799 -- IF (h_count = 799) THEN h_count <= "0000000000"; ELSE h_count <= h_count + 1; END IF; --Generate Horizontal Sync Signal using H_count IF (h_count <= 755) AND (h_count >= 659) THEN horiz_sync <= '0'; ELSE horiz_sync <= '1'; END IF; --V_count counts rows of pixels (480 + extra time for sync signals) -- -- Vert_sync -----------------------------------------------_______------------ -- V_count 0 480 493-494 524 -- IF (v_count >= 524) AND (h_count >= 699) THEN v_count <= "0000000000"; newFrame<='1'; ELSE newFrame<='0'; IF (h_count = 699) THEN v_count <= v_count + 1; newline <='1'; ELSE newline <='0'; END IF; END IF; -- Generate Vertical Sync Signal using V_count IF (v_count <= 494) AND (v_count >= 493) THEN vert_sync <= '0'; ELSE vert_sync <= '1'; END IF; -- Generate Video on Screen Signals for Pixel Data IF (h_count <= 639) THEN video_on_h <= '1'; pixel_column <= h_count; ELSE video_on_h <= '0'; END IF; IF (v_count <= 479) THEN video_on_v <= '1'; pixel_row <= v_count; ELSE video_on_v <= '0'; END IF; -- Put all video signals through DFFs to elminate any delays that cause a blurry image red_out <= red AND video_on; green_out <= green AND video_on; blue_out <= blue AND video_on; horiz_sync_out <= horiz_sync; vert_sync_out <= vert_sync; END PROCESS; END a;