-- Company:
-- Engineer: Alessio Orlando
--
-- Create Date:    09:49:05 12/27/2018
-- Design Name:
-- Module Name:    Controllo_lezioni_TECD - Behavioral
-- Project Name:
-- Target Devices:
-- Tool versions:
-- Description:
--
-- Dependencies:
--
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;

entity Controllo_lezioni_TECD is
    Port ( clk : in  STD_LOGIC;
           rst : in  STD_LOGIC;
           badge : in  STD_LOGIC;--badge letto 1 per aprire, 0 per chiudere la sessione
           col : in  STD_LOGIC_VECTOR (3 downto 1);--colonna del tastierino
           row : in  STD_LOGIC_VECTOR (4 downto 1);--riga del tastierino
           state_debug: out std_logic_vector(3 downto 0);
           output : out  STD_LOGIC_VECTOR (2 downto 1));----vettore a 2
--vettore a 2: 00 attesa iniziale(sess. chiusa), 01 seq.riconosciuta, 10 errore, 11 sessione aperta
end Controllo_lezioni_TECD;

--tastierino

--          row
--         100  010  001
--col 1000   1     2     3
--    0100   4     5     6
--    0010   7     8     9
--    0001   *     0     #

architecture Behavioral of Controllo_lezioni_TECD is

--dichiaraziamo un nuovo tipo stato
type state is (s0,s1,s2,s3,s4,s5,s6,s7,s8,s9);


--dichiarazione segnali utilizzati nel processo per identificare lo stato corrente e futuro
signal current_state, next_state: state;

begin

--processo di sincronizzazione del reset
synchronous_process: process(clk, rst)

begin
    if rising_edge(clk) then
        if rst = '1' then
        current_state <= s0;
        else
        current_state <= next_state;
        end if;
    end if;
end process;

--processo principale tramite il quale si descrive il comportamento dell'automa di Mealy
next_state_and_output_Mealy: process(current_state, badge, col, row)

begin
case current_state is

when s0 =>if(badge = '1') then --lettura badge 1
             next_state <= s1;
          output <="01";--ingresso inserito con successo
          else
          next_state <= s0; --il badge resta a 0
             output<= "00";
             end if;
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

--alla lettura del badge '1' si transita in s1

when s1=>if(badge='1')then
--non  stato inserito nulla da stastierino: resta in attesa (out 00) i s1
         if(col="000" and row="0000") then
             next_state<= s1;
          output<="00"  ;
          elsif(col="001" and row="0001")then--inserimento cancelletto: resta in s1 con out 01
           next_state<= s1;
           output<="01";
           elsif(col="010" and row="0001") then--inserimento 0: va in s3 con out 01
            next_state <= s3;
            output <= "01";
            else--nessuna delle precedenti: va in errore in s2 con out 10
                next_state<= s2;
                output<= "10";
            end if;
         else--badge=0 quindi torna in s0
         next_state<= s0;
         output<= "00";
         end if;
            state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s2 =>if(badge='1')then
--non  stato inserito nulla da tastierino: resta in attesa (out 00) i s2
             if(col="000" and row="0000") then
           next_state<= s2;
           output<="00"  ;
           elsif(col="001" and row="0001")then--inserimento cancelletto
            next_state<= s1;
            output<="01";
          else
            next_state <= s2;
            output <= "10";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if; --chiusura primo if
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s3 => if(badge='1')then
--non e' stato inserito nulla da stastierino: resta in attesa (out 00) i s3
           if(col="000" and row="0000") then
            next_state<= s3;
            output<="00"  ;
            elsif(col="001" and row="0001")then--inserimento cancelletto
             next_state<= s3;
             output<="01";
             elsif((col="010" and row="0001") or (col="100" and row= "1000")) then--inserimento 0 o 1
              next_state <= s5;
              output <= "01";
           else
           next_state<= s4;
           output<= "10";
           end if;
           else
           next_state<= s0;
           output<= "00";
           end if;
              state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s4 =>if(badge='1')then
--non e' stato inserito nulla da stastierino: resta in attesa (out 00) i s4
          if(col="000" and row="0000") then
            next_state<= s4;
            output<="00";
            elsif(col="001" and row="0001")then--inserimento cancelletto
             next_state<= s3;
             output<="01";
          else
            next_state <= s4;
            output <= "01";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if;
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s5 =>if(badge='1')then
--non  stato inserito nulla da stastierino: resta in attesa (out 00) i s5
          if(col="000" and row="0000") then
            next_state<= s5;
            output<="00"  ;
            elsif(col="001" and row="0001")then--inserimento cancelletto
             next_state<= s5;
             output<="01";
                 --inserimento 1 o 2
             elsif((col="010" and row="1000") or (col="100" and row= "1000")) then
              next_state <= s7;
              output <= "01";
          else
            next_state<= s6;
            output<= "10";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if;
          state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s6 =>if(badge='1')then
--non  stato inserito nulla da stastierino: resta in attesa (out 00) i s6
          if(col="000" and row="0000") then
            next_state<= s6;
            output<="00"  ;
            elsif(col="001" and row="0001")then--inserimento cancelletto
              next_state<= s5;
              output<="01";
          else
            next_state <= s6;
            output <= "10";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if;
          state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s7 =>if(badge='1')then
--non  stato inserito nulla da stastierino: resta in attesa (out 00) i s7
          if(col="000" and row="0000") then
            next_state<= s7;
            output<="00"  ;
            elsif(col="001" and row="0001")then--inserimento cancelletto
              next_state<= s7;
              output<="01";
                  --inserimento * per confermare apertura sessione
              elsif(col="100" and row="0001") then
               next_state <= s9;
               output <= "01";
          else
            next_state<= s8;
            output<= "10";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if;
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s8 =>if(badge='1')then
--non e' stato inserito nulla da stastierino: resta in attesa (out 00) i s8
          if(col="000" and row="0000") then
            next_state<= s8;
            output<="00";
            elsif(col="001" and row="0001")then--inserimento cancelletto
              next_state<= s7;
              output<="01";
          else
            next_state <= s8;
            output <= "10";
          end if;
          else
          next_state<= s0;
          output<= "00";
          end if;
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

when s9 =>if(badge = '1') then
             next_state <= s9;
             output <="11";--apertura lezione
             else
             next_state <= s0;
             output<= "00";
             end if;
             state_debug<= conv_std_logic_vector(state'POS(current_state),4);

end case;
end process;
end Behavioral;