LIBRARY ieee,lpm;
USE lpm.lpm_components.all;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
USE ieee.std_logic_unsigned.all;

ENTITY lcdmpddr IS
PORT(	sclk,start,clear	:in		std_logic;
		prom_data	:in 	std_logic_vector(8 downto 0);
		sel				:in 	std_logic_vector(1 downto 0);
		en,r_w,d_i		:out	std_logic;
		promadr			:out 	std_logic_vector(7 downto 0);
		db				:out	std_logic_vector(7 downto 0));
END lcdmpddr;

ARCHITECTURE lcdmpddr_arch OF lcdmpddr IS
signal stks			:std_logic_vector(3 downto 0);
signal ssk		:std_logic_vector(1 downto 0);
signal cntm			:std_logic_vector(8 downto 0);
signal cntp			:std_logic_vector(2 downto 0);
signal prom_q		:std_logic_vector(8 downto 0);
signal dbnc,lcden		:std_logic;
signal scount		:std_logic_vector(26 downto 0);
signal clk,clkm		:std_logic;

BEGIN
  process(sclk)
  begin
    if (sclk'event and sclk='1')  then
      if clear='1' then scount<="000000000000000000000000000";
	  else scount <= scount +1;
	  end if;
    end if;
  end process;
	
  clk <= scount(15); --20m/32768 =1.5ms 16	 

  process(sel)
  begin
    case  sel is 
        when "00" => clkm <= scount(18);--6ms
        when "01" => clkm <= scount(19);
        when "10" => clkm <= scount(20);
        when "11" => clkm <= scount(21);
	end case;
  end process;

  process (cntm)
  begin
    IF (cntm  >= "001000101"  and cntm < "101000110" )then 
      promadr <= "01000101"; lcden <= '0';
    elsif (cntm >= "110001100" )then 
      promadr <= "10001100"; lcden <= '0';
    else 
      promadr <= cntm(7 DOWNTO 0); lcden <= '1';
    end if;
  end process;
  
  prom_q <= prom_data; 
	
  process(clk, clkm)
  begin
    if (clkm'event and clkm='1')  then
      if clear='1' then
        cntm<="000000000";
      elsif (cntp="101") then 
        if cntm ="111111111" then cntm<="000000000";
        else cntm<=cntm+1;
        end if;
      else cntm<=cntm;	
      end if;
    end if;

    if clk'event and clk='1' then
      if clear='1' then
        stks<="0000";
        cntp<="000";
        ssk<="00";
      else
        dbnc<= (start or clkm or clear );
        r_w<= not (stks(0) or stks(1) or stks(2));
        en<=stks(1) and lcden  ;

        case ssk is
             when "00" =>
                 if dbnc='1' then ssk<="01";
                 else ssk<="00";
                 end if;
             when "01" => ssk<="10";
             when "10" =>
                 if dbnc='0' then ssk<="00";
                 else ssk<="10";
                 end if;
             when "11" => ssk<="00";
             when others=>
        end case;
			
        case stks is
             when "0000" =>
                 if ssk(0)='1' then stks<="0001";
                 else stks<="0000";
                 end if;
             when "0001" => stks<="0010";
             when "0010" => stks<="0100";
             when "0100" => stks<="1000";
             when "1000" =>
                 if (cntp(2)='0') then
                   stks<="0001";
                 elsif cntp="101" then stks<="0000";
                 else stks<="1000";
                 end if;
             when others=> stks<="0000";
        end case;
      end if;

      if (stks(3)='1' and cntp/="101") then 
         cntp<=cntp+1;
      else cntp<=cntp;
      end if;	

      if (cntp="101") and (prom_q(8)='0') then 
        d_i<='1';
      else  d_i<='0';
      end if;

      case cntp is
           when "000" => db<="00111000";         -- LCD Initialization
           when "001" => db<="00001110";
           when "010" => db<="00000110";
           when "011" => db<="00000001";
           when "100" => db<="10000000";
           when "101" => db<=prom_q(7 DOWNTO 0); -- Lcd Display
           when others=> 
      end case;
	end if;
  end process;	
END lcdmpddr_arch;