-- Dateiname: LCD_Controller
-- Design Software : Quartus II 13.0sp1 (64-bit)
--
-- Erstellt:
-- von Kai-Frederik Nessitt 
-- Am 2018
--
-- Verändert:
-- Von Bouchnak Wassim 
-- Am 07.08.2021
--
-- Es findet die Initialisierung und den Datenfluss zu 8-Bit-Schnittstellen-LCD-Modulen HD44780 statt
-- Zudem wird sowohl der Token im Decoder-Modus als auch die Tastaturdaten
-- im Encoder-Modus ausgewertet und auf dem LCD-Display dargestellt.
--------------------------------------------------------------------------------LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
USE ieee.numeric_std.ALL;ENTITY LCD IS
 GENERIC(
 display_lines : STD_LOGIC ; --number of display lines (0 = 1-line mode, 1 = 2-line mode)
 character_font : STD_LOGIC ; --font (0 = 5x8 dots, 1 = 5x10 dots)
 display_on_off : STD_LOGIC ; --display on/off (0 = off, 1 = on)
 cursor : STD_LOGIC ; --cursor on/off (0 = off, 1 = on) 
 blink : STD_LOGIC ; --blink on/off (0 = off, 1 = on 
 inc_dec : STD_LOGIC ; --increment/decrement (0 = decrement, 1 = increment) 
 shift : STD_LOGIC --shift on/off (0 = off, 1 = on)
 ); 
 PORT(
 clk : IN STD_LOGIC; --clock 800 HZ
 reset_n : IN STD_LOGIC; --active low reinitializes lcd
 data_input : IN STD_LOGIC_VECTOR (13 DOWNTO 0); --Token-Signal des Decoders / Morse
 data_keyboard : IN STD_LOGIC_VECTOR (7 DOWNTO 0); --Keyboard-Daten nach Betätigung einer Taste
 enable_Modus : IN STD_LOGIC; --Switch Signal zum Umschalten zwischen dem Decoder 0 und Encoder 1 
 enable_Pause : IN STD_LOGIC; --Pausen-Signal der Morse-Entity zur Überprüfung ob ein Token-Signal "fertig" ist
 done_pressing : IN STD_LOGIC; --gibt an ob die Tastaturtaste losgelassen wurde und die Datenübertragung beendet wurde
 
 rw, rs, e : OUT STD_LOGIC; --read/write, setup/data, and enable for lcd
 lcd_data : OUT STD_LOGIC_VECTOR(7 DOWNTO 0); --data signals for lcd
 lcd_on : OUT STD_LOGIC; -- LCD Power On/Off
 lcd_blon : OUT STD_LOGIC; -- LCD Back Light On/Off
 busy : OUT STD_LOGIC --lcd feedback
 );
 
END LCD;ARCHITECTURE RTL OF LCD IS
 TYPE CONTROL IS(power_up, reset1, reset2, reset3, function_set, display_control, display_clear, mode_set, drop_lcd_en, ready, send, Line2, Return_Home);
 SIGNAL state, next_command : CONTROL;
 
 SIGNAL enable_Pause_p1 : STD_LOGIC; -- altes Signal enable_Pause ALTsig_Pause
 SIGNAL valid_Pause : STD_LOGIC; -- Bestätigung einer neuen Pause im decoder Modus
 
 SIGNAL enable_Modus_p1: STD_LOGIC; -- altes Signal enable_Modus ALTsig_Modus
 SIGNAL Modus_Wechsel: STD_LOGIC;
 
 
 SIGNAL done_pressing_p1: STD_LOGIC; -- altes Signal done_pressing ALTsig_pressing
 SIGNAL valid_done_pressing : STD_LOGIC; -- 
 
 signal char_count : unsigned( 5 downto 0) := "000000"; -- auf dem lcd angezeigt Charakter Zähler
BEGIN
 PROCESS(clk, reset_n)
 VARIABLE clk_count : INTEGER := 0; --event counter for timing
 
 BEGIN
 
 IF reset_n = '0' THEN
 state <= power_up;
 next_command <= reset1; -- reset1
 lcd_on <= '1';
 e <= '0';
 rs <= '0';
 rw <= '0';
 busy <= '0';
 char_count <= (others => '0');
 --char_count := 0;
 clk_count := 0;
 
 ELSIF(clk'EVENT and clk = '1') THEN
 
 -- defaults : somit konnen inpuls signale erzeugt werden wenn die Bedingungen erfüllt sind
 valid_Pause <= '0'; 
 Modus_Wechsel <= '0';
 valid_done_pressing <= '0';
 
 
 -- Shift value in : im nächsten Taktzyklus erfolgt die Zuweisung und somit kann jegliche änderung eines Signals fesgestellt werden
 enable_Pause_p1 <= enable_Pause;
 enable_Modus_p1 <= enable_Modus;
 done_pressing_p1 <= done_pressing;
 
 --Es wird geprüft ob sich das alte Signal zum neuen Signal unterscheidet. Ist dies der Fall, gab es eine positive Flanke 
 IF enable_Pause_p1 = '0' AND enable_Pause = '1' AND enable_Modus = '0' THEN 
 valid_Pause <= '1'; -- pause bestätigt und token bereit und vollständig
 END IF; 
 
 IF (enable_Modus_p1 = '0' AND enable_Modus = '1') or ( enable_Modus_p1 = '1' AND enable_Modus = '0') THEN
 Modus_Wechsel <= '1'; -- switch decoder zum encoder 
 END IF; 
 
 IF done_pressing_p1 = '0' AND done_pressing = '1' AND enable_Modus = '1' THEN
 valid_done_pressing <= '1'; -- done_pressing bestätigt und data_keyboard bereit und vollständig
 END IF;
 
 
 --Beginn des fsm logic
 CASE state IS
 
 
 WHEN power_up => --wait 50 ms to ensure Vdd has risen and required LCD wait is met
 
 busy <= '1';
 
 IF(clk_count < 20) THEN --wait 50 ms
 state <= power_up;
 clk_count := clk_count + 1;ELSE --power-up complete
 clk_count := 0;
 state <= next_command;
 next_command <= drop_lcd_en;
 END IF;
 
 
 WHEN reset1 =>
 
 e <= '1';
 lcd_data <= x"38";
 IF(clk_count < 2) THEN --wait 5 ms
 state <= reset1;
 clk_count := clk_count + 1;ELSE 
 clk_count := 0;
 state <= next_command;
 next_command <= reset2;
 END IF;
 
 
 WHEN reset2 => -- Externer RESET
 e <= '1';
 lcd_data <= x"38"; 
 state <= drop_lcd_en;
 next_command <= reset3;
 
 
 WHEN reset3 => -- Externer RESET
 e <= '1';
 lcd_data <= x"38"; 
 state <= drop_lcd_en;
 next_command <= function_set;
 
 
 WHEN function_set => --function set
 e <= '1';
 lcd_data <= "0011" & display_lines & character_font & "00"; 
 state <= drop_lcd_en;
 next_command <= display_control;
 
 
 WHEN display_control => --display on/off control
 e <= '1';
 lcd_data <= "00001" & display_on_off & cursor & blink; 
 state <= drop_lcd_en;
 next_command <= display_clear; 
 
 
 WHEN display_clear => --display clear
 e <= '1';
 lcd_data <= "00000001"; 
 state <= drop_lcd_en;
 next_command <= mode_set; 
 
 
 WHEN mode_set => --entry mode set
 e <= '1';
 lcd_data <= "00001" & display_on_off & cursor & blink; 
 state <= drop_lcd_en;
 next_command <= ready; 
 
 --initialization complete
 
 WHEN drop_lcd_en =>
 busy <= '1'; 
 e <= '0'; 
 state <= next_command;
 
 WHEN Line2 => --Setze Cursor an den Anfang der zweiten Zeile des Displays 
 busy <= '1'; 
 rs <= '0';
 rw <= '0';
 e <= '1';
 lcd_data <= "11000000";
 char_count <= char_count + 1; 
 state <= drop_lcd_en;
 next_command <= ready;
 
 WHEN Return_Home => 
 busy <= '1'; 
 rs <= '0';
 rw <= '0';
 e <= '1';
 lcd_data <= "00000001"; --clear Display 
 --char_count := 0; 
 char_count <= (others => '0'); 
 state <= drop_lcd_en;
 next_command <= ready;
 
 WHEN ready =>
 busy <= '0';
 --IF ( char_count = 16 ) THEN
 IF ( char_count = "010000" ) THEN
 state <= Line2;
 --ELSIF ( char_count = 33 ) THEN
 ELSIF ( char_count = "100001" ) THEN
 state <= Return_Home;
 ELSE 
 state <= send; 
 END IF;
 WHEN send =>
 busy <= '1';
 
 
 IF ( Modus_Wechsel = '1') THEN
 state <= Return_Home;
 
 ELSIF( valid_Pause = '1') THEN
 rs <= '1';
 rw <= '0';
 e <= '1';
 
 CASE data_input IS
 
 --Buchstaben
 WHEN "00000000000111" => lcd_data <=x"41"; -- A
 WHEN "00000011010101" => lcd_data <=x"42"; -- B
 WHEN "00000011011101" => lcd_data <=x"43"; -- C
 WHEN "00000000110101" => lcd_data <=x"44"; -- D
 WHEN "00000000000001" => lcd_data <=x"45"; -- E -1
 WHEN "00000001011101" => lcd_data <=x"46"; -- F
 WHEN "00000000111101" => lcd_data <=x"47"; -- G
 WHEN "00000001010101" => lcd_data <=x"48"; -- H
 WHEN "00000000000101" => lcd_data <=x"49"; -- I
 WHEN "00000001111111" => lcd_data <=x"4A"; -- J
 WHEN "00000000110111" => lcd_data <=x"4B"; -- K
 WHEN "00000001110101" => lcd_data <=x"4C"; -- L
 WHEN "00000000001111" => lcd_data <=x"4D"; -- M
 WHEN "00000000001101" => lcd_data <=x"4E"; -- N
 WHEN "00000000111111" => lcd_data <=x"4F"; -- O
 WHEN "00000001111101" => lcd_data <=x"50"; -- P
 WHEN "00000011110111" => lcd_data <=x"51"; -- Q
 WHEN "00000000011101" => lcd_data <=x"52"; -- R
 WHEN "00000000010101" => lcd_data <=x"53"; -- S
 WHEN "00000000000011" => lcd_data <=x"54"; -- T -2
 WHEN "00000000010111" => lcd_data <=x"55"; -- U
 WHEN "00000001010111" => lcd_data <=x"56"; -- V
 WHEN "00000000011111" => lcd_data <=x"57"; -- W
 WHEN "00000011010111" => lcd_data <=x"58"; -- X
 WHEN "00000011011111" => lcd_data <=x"59"; -- Y
 WHEN "00000011110101" => lcd_data <=x"5A"; -- Z
 
 --Zahlen
 WHEN "00001111111111" => lcd_data <=x"30"; -- 0
 WHEN "00000111111111" => lcd_data <=x"31"; -- 1
 WHEN "00000101111111" => lcd_data <=x"32"; -- 2
 WHEN "00000101011111" => lcd_data <=x"33"; -- 3
 WHEN "00000101010111" => lcd_data <=x"34"; -- 4
 WHEN "00000101010101" => lcd_data <=x"35"; -- 5
 WHEN "00001101010101" => lcd_data <=x"36"; -- 6
 WHEN "00001111010101" => lcd_data <=x"37"; -- 7
 WHEN "00001111110101" => lcd_data <=x"38"; -- 8
 WHEN "00001111111101" => lcd_data <=x"39"; -- 9
 
 --Sonderzeichen
-- WHEN "00000111110111" => lcd_data <=x"8F"; -- Å
 WHEN "00000001110111" => lcd_data <=x"E1"; -- Ä
-- WHEN "00000111010111" => lcd_data <=x"8A"; -- È
-- WHEN "00000101110101" => lcd_data <=x"90"; -- É
 WHEN "00000011111101" => lcd_data <=x"EF"; -- Ö
 WHEN "00000001011111" => lcd_data <=x"F5"; -- Ü
 WHEN "01010111110101" => lcd_data <=x"E2"; -- ß
 WHEN "00110111011101" => lcd_data <=x"3B"; -- ;
 WHEN "00010111110101" => lcd_data <=x"3F"; -- ?
 WHEN "00110101010111" => lcd_data <=x"2D"; -- -
 WHEN "00010111110111" => lcd_data <=x"5F"; -- _
-- WHEN "00001111011111" => lcd_data <=x"A5"; -- Ñ
 WHEN "00011101110111" => lcd_data <=x"2E"; -- .
 WHEN "00111101011111" => lcd_data <=x"2C"; -- ,
 WHEN "00111111010101" => lcd_data <=x"3A"; -- :
 WHEN "00001101111101" => lcd_data <=x"28"; -- (
 WHEN "00110111110111" => lcd_data <=x"29"; -- )
 WHEN "00011111111101" => lcd_data <=x"27"; -- '
 WHEN "00001101010111" => lcd_data <=x"3D"; -- =
 WHEN "00000111011101" => lcd_data <=x"2B"; -- +
 WHEN "00001101011101" => lcd_data <=x"2F"; -- /
 WHEN "00011111011101" => lcd_data <=x"40"; -- @
 
 WHEN OTHERS => lcd_data <= x"00"; 
 
 END CASE;char_count <= char_count + 1; 
 state <= drop_lcd_en;
 elsif (valid_done_pressing = '1') THEN
 rs <= '1';
 rw <= '0';
 e <= '1';
 
 
 CASE data_keyboard IS
 
 --Buchstaben
 WHEN x"1C" => lcd_data <=x"41"; -- A
 WHEN x"32" => lcd_data <=x"42"; -- B
 WHEN x"21" => lcd_data <=x"43"; -- C
 WHEN x"23" => lcd_data <=x"44"; -- D
 WHEN x"24" => lcd_data <=x"45"; -- E
 WHEN x"2B" => lcd_data <=x"46"; -- F
 WHEN x"34" => lcd_data <=x"47"; -- G
 WHEN x"33" => lcd_data <=x"48"; -- H
 WHEN x"43" => lcd_data <=x"49"; -- I
 WHEN x"3B" => lcd_data <=x"4A"; -- J
 WHEN x"42" => lcd_data <=x"4B"; -- K
 WHEN x"4B" => lcd_data <=x"4C"; -- L
 WHEN x"3A" => lcd_data <=x"4D"; -- M
 WHEN x"31" => lcd_data <=x"4E"; -- N
 WHEN x"44" => lcd_data <=x"4F"; -- O
 WHEN x"4D" => lcd_data <=x"50"; -- P
 WHEN x"15" => lcd_data <=x"51"; -- Q
 WHEN x"2D" => lcd_data <=x"52"; -- R
 WHEN x"1B" => lcd_data <=x"53"; -- S
 WHEN x"2C" => lcd_data <=x"54"; -- T
 WHEN x"3C" => lcd_data <=x"55"; -- U
 WHEN x"2A" => lcd_data <=x"56"; -- V
 WHEN x"1D" => lcd_data <=x"57"; -- W
 WHEN x"22" => lcd_data <=x"58"; -- X
 WHEN x"1A" => lcd_data <=x"59"; -- Y
 WHEN x"35" => lcd_data <=x"5A"; -- Z
 
 --Zahlen
 WHEN x"45" => lcd_data <=x"30"; -- 0
 WHEN x"16" => lcd_data <=x"31"; -- 1
 WHEN x"1E" => lcd_data <=x"32"; -- 2
 WHEN x"26" => lcd_data <=x"33"; -- 3
 WHEN x"25" => lcd_data <=x"34"; -- 4
 WHEN x"2E" => lcd_data <=x"35"; -- 5
 WHEN x"36" => lcd_data <=x"36"; -- 6
 WHEN x"3D" => lcd_data <=x"37"; -- 7
 WHEN x"3E" => lcd_data <=x"38"; -- 8
 WHEN x"46" => lcd_data <=x"39"; -- 9
 
 --Sonderzeichen
-- WHEN x"" => lcd_data <=x"8F"; -- Å
 WHEN x"52" => lcd_data <=x"E1"; -- Ä
-- WHEN x"" => lcd_data <=x"8A"; -- È
-- WHEN x"" => lcd_data <=x"90"; -- É
 WHEN x"4C" => lcd_data <=x"EF"; -- Ö
 WHEN x"54" => lcd_data <=x"F5"; -- Ü
 WHEN x"4E" => lcd_data <=x"E2"; -- ß
-- WHEN x"" => lcd_data <=x"3B"; -- ;
-- WHEN x"" => lcd_data <=x"3F"; -- ?
 WHEN x"4A" => lcd_data <=x"2D"; -- -
-- WHEN x"" => lcd_data <=x"5F"; -- _
-- WHEN x"" => lcd_data <=x"A5"; -- Ñ
 WHEN x"49" => lcd_data <=x"2E"; -- .
 WHEN x"41" => lcd_data <=x"2C"; -- ,
-- WHEN x"" => lcd_data <=x"3A"; -- :
-- WHEN x"" => lcd_data <=x"28"; -- (
-- WHEN x"" => lcd_data <=x"29"; -- )
-- WHEN x"" => lcd_data <=x"27"; -- '
-- WHEN x"" => lcd_data <=x"3D"; -- =
 WHEN x"5B" => lcd_data <=x"2B"; -- +
-- WHEN x"" => lcd_data <=x"2F"; -- /
-- WHEN x"" => lcd_data <=x"40"; -- @
 WHEN x"29" => lcd_data <=x"20"; -- " "
 
 
 WHEN OTHERS => lcd_data <= x"00"; 
 
 END CASE;char_count <= char_count + 1; 
 state <= drop_lcd_en;END IF;  
 END CASE; 
 
 
 END IF;END PROCESS;
 END RTL;