--*********************************************
--
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL ;
USE IEEE.STD_LOGIC_UNSIGNED.ALL ;

LIBRARY altera;
USE altera.maxplus2.ALL;
--
--*********************************************
--
ENTITY elec_lock IS
	PORT (  
		CLK_4M   : IN   STD_LOGIC ;                     --system original clock 4M
     	CLK_SCAN : OUT  STD_LOGIC_VECTOR (3 downto 0) ; --scan sequence
		KEY_IN   : IN   STD_LOGIC_VECTOR (2 downto 0) ; --KEY IN button code
		FLAG_NUMB : OUT STD_LOGIC ;
		FLAG_FUNC : OUT STD_LOGIC ;
		LED_COM :  OUT STD_LOGIC ;                      -- for LP-2900 only
		CLEAR : OUT STD_LOGIC ;                         --** 
		ENLOCK : OUT  STD_LOGIC ;                       --1:LOCK, 0:UNLOCK
		NUMB_CNT : OUT STD_LOGIC_VECTOR (2 DOWNTO 0) ;
		BCD_CODE :  OUT STD_LOGIC_VECTOR (15 DOWNTO 0) ;
		SELOUT : OUT STD_LOGIC_VECTOR (1 DOWNTO 0) ;    --FIT TO LP-2900
		SEGOUT		: OUT  STD_LOGIC_VECTOR(6 DOWNTO 0) -- SEG7 Display O/P
		);
END elec_lock ;
--
--*********************************************
ARCHITECTURE a OF elec_lock IS
	component debouncing
		port(  d_in   : IN STD_LOGIC ;
			   clk    : IN STD_LOGIC ;	
			   d_out  : OUT STD_LOGIC ) ;
	end component ;

	SIGNAL CLK : STD_LOGIC ;	
	SIGNAL CLK_KEYBOARD : STD_LOGIC_VECTOR(1 downto 0) ;	
	SIGNAL CLK_DEBOUNCE : STD_LOGIC ;	
	SIGNAL CLK_DISPLAY  : STD_LOGIC_VECTOR(1 downto 0) ;	
	SIGNAL C          : STD_LOGIC_VECTOR(2 downto 0) ;
	SIGNAL N          : STD_LOGIC_VECTOR(3 downto 0) ;
	SIGNAL F          : STD_LOGIC_VECTOR(3 downto 0) ;
	SIGNAL FN         : STD_LOGIC ;
	SIGNAL FF         : STD_LOGIC ;
	SIGNAL SEL        : STD_LOGIC_VECTOR (3 downto 0) ;	
	SIGNAL OUT_NUMB :  STD_LOGIC_VECTOR(3 downto 0) ;
	SIGNAL OUT_FUNC :   STD_LOGIC_VECTOR(3 downto 0) ;
    SIGNAL ACC : STD_LOGIC_VECTOR (15 DOWNTO 0) ;
    SIGNAL REG : STD_LOGIC_VECTOR (15 DOWNTO 0) ;
	SIGNAL RR2 : STD_LOGIC ;                        -- ** RR2 = Clear
	SIGNAL QA, QB, BB : STD_LOGIC ;
	SIGNAL NC : STD_LOGIC_VECTOR (2 DOWNTO 0) ;
	SIGNAL 	DB    	: STD_LOGIC_VECTOR( 3 DOWNTO 0);-- Number TO Display 	
	SIGNAL  SEG		: STD_LOGIC_VECTOR( 6 DOWNTO 0);-- SEG7 Display Signal
BEGIN
--*******************************************
-- CONNECTION 
	OUT_NUMB <= N ;
	OUT_FUNC <= F ;
	FLAG_NUMB <= FN  ;
	FLAG_FUNC <= FF  ;
	CLK_DEBOUNCE <= CLK ;
	--CLK_DISPLAY <= C_DISPLAY ;
 	NUMB_CNT<= NC ;
	SEGOUT(6 DOWNTO 0) <= SEG;	-- Seven Segment Display	
	SELOUT <= CLK_DISPLAY ;
	LED_COM <= '1' ;            --For LP-2900 only 
--
--*********************************************
-- scan signal generator 
counter : block
	Signal  Q   : STD_LOGIC_VECTOR(22 DOWNTO 0);           	
 	Signal 	S   : STD_LOGIC_VECTOR(1 DOWNTO 0) ;  --keyboard scan about 15Hz ***
	SIGNAL 	SEL : STD_LOGIC_VECTOR (3 downto 0);  --1110-1101-1011-0111

BEGIN

	PROCESS (Clk_4M)				       
	Begin
		IF CLK_4M'Event AND CLK_4M = '1' then
			Q <= Q+1;
		END IF;
	END PROCESS;
			CLK <= Q(0) ;  --CLK = CLK_DEBOUNCE
			CLK_KEYBOARD <= Q(5 DOWNTO 4) ;	    -- ***00-01-10-11
			CLK_DISPLAY  <= Q(5 DOWNTO 4) ;
--			CLK <= Q(14) ;  --CLK = CLK_DEBOUNCE
--			C_KEYBOARD <= Q(18 DOWNTO 17) ;	    -- ***00-01-10-11
--			C_DISPLAY  <= Q(18 DOWNTO 17) ;
-- To generate keyboard scan sequence  1110->1101->1011->0111								     
			SEL <= 	"1110" WHEN CLK_KEYBOARD=0 ELSE
					"1101" WHEN CLK_KEYBOARD=1 ELSE
					"1011" WHEN CLK_KEYBOARD=2 ELSE
					"0111" ; 
	CLK_SCAN <= SEL ;
end block counter ;
--
--*********************************************
--
--debounuing ckt
debounuing : block
begin
	U1: debouncing PORT MAP (
					d_in => key_in(0) ,
					d_out => C(0) ,
					clk => CLK
					);
	U2: debouncing PORT MAP (
					d_in => key_in(1) ,
					d_out => C(1)  ,
					clk => CLK
					 );
	U3: debouncing PORT MAP (
					d_in => key_in(2) ,
					d_out => C(2)  ,
	     			clk => CLK 
					);
END block debounuing  ;
--
--******************************************************
--key_decoder
key_decoder : block 
	signal Z : std_logic_VECTOR(4 downto 0) ;   --KEY POSITION
	SIGNAL R1, R0 : STD_LOGIC ;

begin
	PROCESS(clk)
	begin
		Z <= CLK_KEYBOARD & C ;
		IF CLK'EVENT  AND CLK = '1'  THEN
			case Z is
					when "11101" => N <= "0000" ;--0
					when "00011" => N <= "0001" ;--1
					when "00101" => N <= "0010" ;--2
					when "00110" => N <= "0011" ;--3
					when "01011" => N <= "0100" ;--4
					when "01101" => N <= "0101" ;--5
					when "01110" => N <= "0110" ;--6
					when "10011" => N <= "0111" ;--7
					when "10101" => N <= "1000" ;--8
					when "10110" => N <= "1001" ;--9
					when others   => N <= "1111" ;
			end case ;
		END IF ;
--****************************
		IF CLK'EVENT  AND CLK = '1'  THEN
			case  Z is
					when "11011" => F <= "0100" ;--*_LOCK
					when "11110" => F <= "0001" ;--#_UNLOCK
					when others  => F <= "1000" ;
			end case ;		
		END IF ;
	end process ;

	FN <=  NOT ( N(3) AND N(2) AND N(1) AND N(0) ) ;
	FF <=  ( NOT F(3) AND F(2) AND NOT F(1) AND NOT F(0)) OR (NOT F(3) AND NOT F(2) AND NOT F(1) AND F(0) ) ;
--To generate clear signal for ACC 
PROCESS (CLK)
BEGIN
IF CLK'EVENT  AND CLK = '1'  THEN
R1 <= R0 ; R0 <= FF ; 
END IF ;
RR2 <= R1 AND NOT R0 ;
CLEAR <= RR2 ;
END PROCESS ;



end block key_decoder ;
--
--*****************************************************
--
--
--
--
--*****************************************************
--KEYIN /// BACK /// ALL CLEAR
KEYIN_PROCESS :BLOCK
	SIGNAL RST,D0,D1: STD_LOGIC ;	
BEGIN 
	PROCESS(CLK,FN,RST)
	BEGIN
		IF RST = '1' THEN 
			ACC <= "0000000000000000" ;  --CLEAR INPUT
			NC <= "000" ;
--		ELSIF (CLK'EVENT AND CLK = '1') THEN
		ELSE 
			IF  FN'EVENT AND FN = '1'  THEN 
				IF NC < 4 THEN
					ACC <= ACC(11 DOWNTO 0) & N ;
					BB <= '0' ; 
					NC <= NC + 1 ;
                ELSE 					
					BB <= '1' ;
				END IF ;
			END IF ;
		END IF ;
	END PROCESS ;
--	BIBI <= BB AND NOT D0 ;
    RST  <=  RR2 ;
END BLOCK KEYIN_PROCESS ;
--
--*********************************************
--
LOCK_PROCESS : BLOCK

--	SIGNAL R0, R1 : STD_LOGIC ;

BEGIN
	PROCESS(CLK,F)
	BEGIN
		IF (CLK'EVENT AND CLK = '1') THEN
				IF NC = 4  THEN
					IF F(2) = '1' THEN  --LOCK 
						REG <= ACC ; 
						QA <= '1' ; QB <= '0';
					ELSIF F(0) = '1' THEN     --UNLOCK
						IF  REG = ACC THEN    --CHECK PIN CODE
							QB <= '1' ; QA<= '0';
						END IF ;
					ELSIF  ACC = "0010010110000000" THEN   
                    --To set "2580" is the Universal. pin number
							QB <= '1' ; QA<= '0';
					END IF ;
			    END IF;
	    END IF ;
	END PROCESS ;
END BLOCK LOCK_PROCESS ;

	ENLOCK <= QA AND NOT QB ;
	BCD_CODE <= ACC ;
--
--**********************************************
--
MULTIPLEXER : BLOCK
BEGIN
	DB <= ACC(15 DOWNTO 12) WHEN CLK_DISPLAY = 0 ELSE  	
	      ACC(11 DOWNTO  8) WHEN CLK_DISPLAY = 1 ELSE
	      ACC(7  DOWNTO  4) WHEN CLK_DISPLAY = 2 ELSE
	      ACC(3  DOWNTO  0) WHEN CLK_DISPLAY = 3 ELSE
		  "1111" ;

End Block MULTIPLEXER ;
--
--**********************************************
--
SEVEN_SEGMENT : Block	-- Binary Code -> Segment 7 Code
Begin
		   --gfedcba
	SEG <= 	"0111111" WHEN DB = 0 ELSE
		 	"0000110" WHEN DB = 1 ELSE
 			"1011011" WHEN DB = 2 ELSE
			"1001111" WHEN DB = 3 ELSE
			"1100110" WHEN DB = 4 ELSE
			"1101101" WHEN DB = 5 ELSE
			"1111101" WHEN DB = 6 ELSE
		 	"0000111" WHEN DB = 7 ELSE
 			"1111111" WHEN DB = 8 ELSE
			"1101111" WHEN DB = 9 ELSE
			"1111111";
End Block SEVEN_SEGMENT;											

END a;
--
--*********************************************