vga.txt

基于FPGA的VGA显示器彩条发生器 是必备的VGA原码控制

LIBRARY IEEE;--VGA显示器彩条发生器
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY COLOR IS
PORT(CLK,MD:IN STD_LOGIC;
HS,VS,R,G,B:OUT STD_LOGIC);--行场同步/红，绿，兰
END COLOR;
ARCHITECTURE behav OF COLOR IS
SIGNAL HS1,VS1,FCLK,CCLK:STD_LOGIC;
SIGNAL MMD:STD_LOGIC_VECTOR(1 DOWNTO 0);--方式选择
SIGNAL FS:STD_LOGIC_VECTOR(3 DOWNTO 0);
SIGNAL CC:STD_LOGIC_VECTOR(4 DOWNTO 0);--行同步/横彩条生成
SIGNAL LL:STD_LOGIC_VECTOR(8 DOWNTO 0);--场同步/竖彩条生成?
SIGNAL GRBX:STD_LOGIC_VECTOR(3 DOWNTO 1);--X横彩条
SIGNAL GRBY:STD_LOGIC_VECTOR(3 DOWNTO 1);--Y竖彩条
SIGNAL GRBP:STD_LOGIC_VECTOR(3 DOWNTO 1);
SIGNAL GRB:STD_LOGIC_VECTOR(3 DOWNTO 1);
BEGIN
GRB(2)<=(GRBP(2)XOR MD)AND HS1 AND VS1;
GRB(3)<=(GRBP(3)XOR MD)AND HS1 AND VS1;
GRB(1)<=(GRBP(1)XOR MD)AND HS1 AND VS1;
PROCESS(MD)
BEGIN
IF MD'EVENT AND MD='0'THEN
IF MMD="10"THEN MMD<="00";
ELSE MMD<=MMD+1;END IF;--三种模式
END IF;
END PROCESS;
PROCESS(MMD)
BEGIN
IF MMD="00"THEN GRBP<=GRBX;--选择横彩条
ELSIF MMD="01"THEN GRBP<=GRBY;--选择竖彩条
ELSIF MMD="10"THEN GRBP<=GRBX XOR GRBY;--产生棋盘格
ELSE GRBP<="000";END IF;
END PROCESS;
PROCESS(CLK)
BEGIN
IF CLK'EVENT AND CLK='1'THEN--12MHz 13分频
IF FS=12 THEN FS<="0000";
ELSE FS<=(FS+1);END IF;
END IF;
END PROCESS;
FCLK<=FS(3);CCLK<=CC(4);
PROCESS(FCLK)
BEGIN
IF FCLK'EVENT AND FCLK='1'THEN
IF CC=29 THEN CC<="00000";
ELSE CC<=CC+1;END IF;
END IF;
END PROCESS;
PROCESS(CCLK)
BEGIN
IF CCLK'EVENT AND CCLK='0'THEN
IF LL=481 THEN LL<="000000000";
ELSE LL<=LL+1;END IF;
END IF;
END PROCESS;
PROCESS(CC,LL)
BEGIN
IF CC>23 THEN HS1<='0';--行同步
ELSE HS1<='1';END IF;
IF LL>479 THEN VS1<='0';--场同步
ELSE VS1<='1';END IF;
END PROCESS;
PROCESS(CC,LL)
BEGIN
IF CC<3 THEN GRBX<="111";--横彩条
ELSIF CC<6 THEN GRBX<="110";
ELSIF CC<9 THEN GRBX<="101";
ELSIF CC<12 THEN GRBX<="100";
ELSIF CC<15 THEN GRBX<="011";
ELSIF CC<18 THEN GRBX<="010";
ELSIF CC<21 THEN GRBX<="001";
ELSE GRBX<="000";
END IF;
IF LL<60 THEN GRBY<="111";--竖彩条
ELSIF LL<120 THEN GRBY<="110";
ELSIF LL<180 THEN GRBY<="101";
ELSIF LL<240 THEN GRBY<="100";
ELSIF LL<300 THEN GRBY<="011";
ELSIF LL<360 THEN GRBY<="010";
ELSIF LL<420 THEN GRBY<="001";
ELSE GRBY<="000";
END IF;
END PROCESS;
HS<=HS1;VS<=VS1;R<=GRB(2);G<=GRB(3);B<=GRB(1);
END behav;