lcd_driver.vhd

this is a LCD Driver VHDL code

				state<=15;
            counter<=0; 
		end if;
      
		------------------Initialization Complete------------------------
      ---------------WRITE  DATA HAVE  -----------------
      if( Write_TO_LCD='1') then 
				Rs<='1'; 
            RW<='0';
         if(substate=0 and counter=600) then -- wait for Data valid
                DATA<=nhdata_Int;
					 counter<=0;
                substate<=1; 
         elsif(substate=1 and counter=2) then 
                EN<='1'; 
                counter<=0; 
                substate<=2; 
         elsif(substate=2 and counter=12) then 
                EN<='0'; 
                substate<=3; 
                counter<=0; 
         elsif(substate=3 and counter=100) then ---delay for two nible 
                DATA<=nldata_Int;-- IT HAS BEEN FIXED 
                counter<=0; 
                substate<=4; 
         elsif(substate=4 and counter=2) then 
                EN<='1';    
                counter<=0; 
                substate<=5; 
         elsif(substate=5 and counter=12) then 
                EN<='0'; 
                substate<=6; 
                counter<=0; 
          
      --WAIT FOR 2,000 counter          
      elsif(substate=6 and counter=5000) then 
				substate<=0;
				--LED2_Int	<=NOT(LED2_Int);				
				Cursor<=Cursor+1;
				Write_TO_LCD<='0';				
				counter<=0; 
      end if; 
		end if;
		------------------ for instruction------------------
		if(instruct_to_lcd='1')then 
				RS<='0'; 
            RW<='0';
				
			if(substate=0 and counter=600) then 
                DATA<=nhdata_Int;
                counter<=0; 
                substate<=1; 
         elsif(substate=1 and counter=2) then 
                EN<='1'; 
                counter<=0; 
                substate<=2; 
         elsif(substate=2 and counter=12) then 
                EN<='0'; 
                substate<=3; 
                counter<=0; 
         elsif(substate=3 and counter=100) then 
                DATA<=nldata_Int;
                counter<=0; 
                substate<=4; 
         elsif(substate=4 and counter=2) then 
                EN<='1';    
                counter<=0; 
                substate<=5; 
         elsif(substate=5 and counter=12) then 
                EN<='0'; 
                substate<=6; 
					 counter<=0;  
--WAIT FOR 640000 counter  for instruction 1.6 ms        
			elsif(substate=6  and counter=64000) then 
				--	LED2_Int	<=NOT(LED2_Int);				
					substate<=0;
					Cursor<=Cursor+1;	
					counter<=0;
				end if;
			end if; 
				
				----write speed and Range-----------
				
				if((LCD_Init_done='1'))then--
						Write_TO_LCD	<='0';
						--instruct_to_lcd<='1';
						if ( Cursor=0 and counter=100) then	--;Clear Screen & Returns the Cursor Home
							instruct_to_lcd<='1';
							nhdata_Int			<=	"0000";-- 	 Clear LCD
							nldata_Int			<=	"0001";--	 Clear LCD
					------------------speed-------------------------------------
						elsif ( Cursor=1 ) then
							instruct_to_lcd<='0';
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0101";--writ S
							nldata_Int			<=	"0011";--writ S
						--	RS<='1';
						elsif(Cursor=2)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0111";--writ p
							nldata_Int			<=	"0000";--writ p
							--RS<='1';
						elsif(Cursor=3)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--writ e-
							nldata_Int			<=	"0101";--writ e-
						--	RS<='1';
						elsif(Cursor=4)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--writ e-
							nldata_Int			<=	"0101";--writ e-
						--	RS<='1';
						elsif(Cursor=5)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--writ d-
							nldata_Int			<=	"0100";--writ d-
						--	RS<='1';
						elsif(Cursor=6)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0011";--writ :-
							nldata_Int			<=	"1010";--writ :-
						--	RS<='1';
						elsif (Cursor=7)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--writ space 
							nldata_Int			<=	"0000";--writ space
						elsif(Cursor=8)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	Speed_digit1(7 downto 4);--writ digit 1 of speed
							nldata_Int			<=	Speed_digit1(3 downto 0);--writ digit 1 of speed
						--	RS<='1';
						elsif(Cursor=9)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	speed_digit2(7 downto 4);--writ digit 2 of speed
							nldata_Int			<=	speed_digit2(3 downto 0);--writ digit 2 of speed
						--	RS<='1';
						elsif(Cursor=10)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0010";--writ .
							nldata_Int			<=	"1110";--writ .
						--	RS<='1';
						elsif(Cursor=11)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	speed_digit3(7 downto 4);--writ digit3 of speed
							nldata_Int			<=	speed_digit3(3 downto 0);--writ digit 3 of speed
					--		RS<='1';
					
					
						elsif(Cursor=12)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--writ space 
							nldata_Int			<=	"0000";--writ space
						--RS<='0'; 				--- instraction
						
						elsif(Cursor=13)then
							Write_TO_LCD	<='1';
							--instruct_to_lcd<='0';
							nhdata_Int			<=	"0110";--writ 	m
							nldata_Int			<=	"1101";--writ 	m
							--RS<='1';		-- befor EN low to high
						elsif(Cursor=14)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0010";--writ 	/
							nldata_Int			<=	"1111";--writ 	/
				--			RS<='1';
						elsif(Cursor=15)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0111";--writ 	s
							nldata_Int			<=	"0011";--writ 	s
--							RS<='1';
--						
--						------------------------ move Cursor to next line---------
--						---------------------- move Cursor to next line--------- command 11000000
						elsif(Cursor=16)then
							--RS<='0'; --- instraction
							Write_TO_LCD	<='0';
							instruct_to_lcd<='1';
							nhdata_Int			<=	"1100";--move Cursor to next line #XC0
							nldata_Int			<=	"0000";--move Cursor to next line
----							
						------------------------range-------------------------------------
						elsif(Cursor=17)then
							--RS<='1'; 
							Write_TO_LCD	<='1';
							instruct_to_lcd<='0';
							nhdata_Int			<=	"0101";--write 	R
							nldata_Int			<=	"0010";--write 	R
						elsif(Cursor=18)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--write 	a
							nldata_Int			<=	"0001";--write 	a
						--	RS<='1';
						elsif(Cursor=19)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--write 	n
							nldata_Int			<=	"1110";--write 	n
						--	RS<='1';
						elsif(Cursor=20)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--write 	g
							nldata_Int			<=	"0111";--write 	g
						--	RS<='1';
						elsif (Cursor=21)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--writ e-
							nldata_Int			<=	"0101";--writ e-
						elsif(Cursor=22)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0011";--write :
							nldata_Int			<=	"1010";--write :
						--	RS<='1';
						elsif(Cursor=23)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--writ space 
							nldata_Int			<=	"0000";--writ space
						elsif(Cursor=24)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	Range_digit1(7 downto 4);--write digit 1	of Range
							nldata_Int			<=	Range_digit1(3 downto 0);--write digit 1	of Range
						--	RS<='1';
						elsif(Cursor=25)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	Range_digit2(7 downto 4);--write digit 2	of Range
							nldata_Int			<=	Range_digit2(3 downto 0);--write digit 2	of Range
						--	RS<='1';
						elsif(Cursor=26)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0010";--write .
							nldata_Int			<=	"1110";--write .
						--	RS<='1';
						elsif(Cursor=27)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	Range_digit2(7 downto 4);--write digit 3	of Range
							nldata_Int			<=	Range_digit2(3 downto 0);--write digit 3	of Range
						--	RS<='1';
						
						elsif(Cursor=28)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--write space 
							nldata_Int			<=	"0000";--write space
						--	RS<='1';
						
						elsif(Cursor=29)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"0110";--write 	m
							nldata_Int			<=	"1101";--write 	m
							--RS<='1';		-- befor EN low to high
						elsif(Cursor=30)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--write space 
							nldata_Int			<=	"0000";--write space
						elsif(Cursor=31)then
							Write_TO_LCD	<='1';
							nhdata_Int			<=	"1010";--write space 
							nldata_Int			<=	"0000";--write space
						elsif((Cursor=32) and (exceed_Speed='1'))then
								instruct_to_lcd<='1';
								Write_TO_LCD	<='0';
								nhdata_Int			<=	"0000";	---care in this case Display on, Cursor off, Blink off
								nldata_Int			<=	"1111";	---care in this case Display on, Cursor off, Blink off
						elsif((Cursor=32) and (exceed_Speed='0'))then
							Write_TO_LCD	<='0';
							LCD_Init_done	<='0';	--wait for new data
							Write_complete	<='1';
						elsif((Cursor=33))then
							instruct_to_lcd<='0';
							Write_TO_LCD	<='0';
							LCD_Init_done	<='0';	--wait for new data
							Write_complete	<='1';
							
----						----------------------end of data-----------------------------------
----						------------------------range------------------------------
----						
						end if;
				end if;
				
				New_Data_Previous		<=	New_Data;
			if ((New_Data='1')and(New_Data_Previous='0'))then
				LCD_Init_done	<='1';
				Cursor<=0;
				counter<=0;
				Write_complete	<='0';
			end if;

end if;--rising_edge

end process; 

end Behavioral;