12864.txt

用VHDL 语言驱动DM128*64LCD程序

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use IEEE.STD_LOGIC_ARITH.ALL;
entity LCD is
   generic(divide_to_100k:integer:=100000);
    port(clk:in std_logic;
            rw,rs,e,lcd_rst:out std_logic;
            lcd_data:out std_logic_vector(7 downto 0));
   end LCD ;
architecture tcl of LCD is
   signal clk_100k:std_logic;
   type state is(s0,s1,s2,s3,s4,s5,s6,s7,s8,s9,s10);
   signal current_s:state;
   type data_buffer is array(0 to 15)of std_logic_vector(7 downto 0);
   constant data_buf:data_buffer:=(x"d2",x"ba",x"be",x"a7",
                                 x"cf", x"d4",x"ca",x"be",x"c4",
                                   x"a3",x"bf",x"e9",x"c9",
                                    x"e8",x"bc",x"c6");
   begin
--U1:divclk1 port map(clk,clk_100k);
process(clk)
  variable cnt:integer range 0 to divide_to_100k;
      begin
        if(clk'event and clk='1')then cnt:=cnt+1;
            if(cnt=divide_to_100k)then cnt:=0;
            end if;
            if(cnt<divide_to_100k/2) then clk_100k<='0';
            else clk_100k<='1';
            end if;
        end if;
end process;
   process(clk_100k)
     variable cnt1:integer range 0 to 10000;
     variable cnt_1:integer range 0 to 1000;
     variable code_cnt:integer range 0 to 13;
     variable data_cnt:integer range 0 to 480;
         begin
         if(clk_100k'event and clk_100k='1')then
            case current_s is 
            when s0=>rw<='1';rs<='1';e<='1';cnt1:=cnt1+1;
                if cnt1<500 then lcd_rst<='0';
                 elsif cnt1<1000 then lcd_rst<='1';
                 elsif cnt1=1000 then
                     lcd_rst<='1';cnt1:=0;current_s<=s1;
                 end if;
            when s1=>cnt_1:=cnt_1+1;
                       if cnt_1<1*3 then e<='1';rs<='0';rw<='0';
                        elsif cnt_1<2*3 then lcd_data<=x"0c";
                        elsif cnt_1<10*3 then e<='0';
                        elsif cnt_1=10*3 then cnt_1:=0;current_s<=s2;
                       end if;
             when s2=>cnt_1:=cnt_1+1;
                       if cnt_1<1*3 then e<='1';rs<='0';rw<='0';
                        elsif cnt_1<2*3 then lcd_data<=x"80";
                        elsif cnt_1<10*3 then e<='0';
                        elsif cnt_1=10*3 then cnt_1:=0;current_s<=s3;
                       end if;
             when s3=>
                       if cnt_1<1*3 then e<='1';rs<='1';rw<='0';
                        elsif cnt_1<2*3 then lcd_data<=data_buf(data_cnt);
                        elsif cnt_1=2*3 then data_cnt:=data_cnt+1;
                        elsif cnt_1<100 then e<='0';
                       end if;
                       cnt_1:=cnt_1+1;
                          if cnt_1=100 then cnt_1:=0;
                                 if data_cnt=16 then current_s<=s4;
                                    data_cnt:=0;
                                  end if;
                          end if;
               when s4=>cnt_1:=cnt_1+1;
                       if cnt_1<1*3 then e<='1';rs<='0';rw<='0';
                        elsif cnt_1<2*3 then lcd_data<=x"88";
                        elsif cnt_1<10*3 then e<='0';
                        elsif cnt_1=10*3 then cnt_1:=0;current_s<=s5;
                       end if;
             when s5=>
                       if cnt_1<1*3 then e<='1';rs<='1';rw<='0';
                        elsif cnt_1<2*3 then lcd_data<=data_buf(data_cnt);
                        elsif cnt_1=2*3 then data_cnt:=data_cnt+1;
                        elsif cnt_1<100 then e<='0';
                       end if;
                       cnt_1:=cnt_1+1;
                          if cnt_1=100 then cnt_1:=0;
                                 if data_cnt=16 then current_s<=s4;
                                    data_cnt:=0;
                                  end if;
                          end if;
               when s6=>NULL;
               when others=>current_s<=s0;
           end case;
      end if;
end process;
end tcl;