library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_arith.all;

entity DigitalClock is
port
(
	CLK_6MHz:	in std_logic;
	RST		:	in std_logic;	
	KEY_IN	:	in std_logic_vector(3 downto 0);
	KEY_OUT	:	out std_logic_vector(3 downto 0);
	SEG_DATA:	out std_logic_vector(7 downto 0);
	SEG_CHOOSE:	out std_logic_vector(2 downto 0);
	FOUT	:	out std_logic
);
end;

architecture archSegment2 of DigitalClock is
constant KEY_DIV	:	integer := 120000;							--按键延时长度
type KEY_STATE is(KS0,KS1,KS2,KS3);
type ARRAY8x1 is array(7 downto 0)of integer range 255 downto 0;  	--8个8位的数据
signal timeValue : ARRAY8x1;										--记录时间
signal keyInBak : std_logic_vector(3 downto 0);						--保存按键的读入值
signal keyOutBak : std_logic_vector(3 downto 0);					--记录按键扫描的输出值
signal delayCount : integer range 16383 downto 0 := 0;				--音符周期计数
signal delay : integer range 16383 downto 0 := 0;					--音符周期
signal clk4Hz : std_logic := '0';									--4Hz计数
signal foutTemp : std_logic := '1';
signal songData : integer range 255 downto 0 := 0;					--用2位10进制数来表示音符,其中十位的1、2、3分别表示音符的低、中、高
																	--个位的1~7分别表示音符1~7
signal songStartFlag : integer range 255 downto 0 := 0;
signal songStopFlag : integer range 255 downto 0 := 0;
begin

KeyScan:process(CLK_6MHz,KEY_IN,RST,songStopFlag)			--按键扫描
variable keyCount : integer range 140000 downto 0 := 0;		--用于按键去抖
variable keyState : KEY_STATE := KS0;						--记录按键扫描的状态
variable keyFlag : integer range 1 downto 0 := 0;			--记录去抖时间是否已到
variable i	: integer range 255 downto 0 := 0;				--用于普通的for loop中
variable outIndex : integer range 3 downto 0 := 0;			--用于扫描输出信号的计数
variable temp : integer range 255 downto 0 := 0;
variable timeCount : integer range 255 downto 0 := 0;		--记录是否达到1s
variable secondCount : integer range 255 downto 0 := 0;		--记录秒钟
variable minuteCount : integer range 255 downto 0 := 0;		--记录秒钟
variable hourCount : integer range 255 downto 0 := 0;		--记录秒钟
begin
	case outIndex is										--产生扫描信号
		when 0 =>
			KEY_OUT <= "0001";
			keyOutBak <= "0001";
		when 1 =>
			KEY_OUT <= "0010";
			keyOutBak <= "0010";
		when 2 =>
			KEY_OUT <= "0100";
			keyOutBak <= "0100";
		when 3 =>
			KEY_OUT <= "1000";
			keyOutBak <= "1000";
		when others =>
			KEY_OUT <= "0001";
			keyOutBak <= "0001";
	end case;
	if(RST = '1')then
		keyState := KS0;
		outIndex := 0;
		for i in 0 to 7 loop
			timeValue(i) <= 0;
		end loop;
	elsif(rising_edge(CLK_6MHz))then					--计时
		if(songStopFlag = 1)then 
			songStartFlag <= 0;
		end if;
		keyCount := keyCount + 1;
		if(keyCount = KEY_DIV)then						--达到20ms
			keyCount := 0;
			keyFlag := 1;
			timeCount := timeCount + 1;
			if(timeCount >= 50)then						--达到1s
				timeCount := 0;
				secondCount := secondCount + 1;
				if(secondCount >= 60)then				--达到1min
					secondCount := 0;
					minuteCount := minuteCount + 1;
					if(minuteCount >= 60)then			--达到1h
						songStartFlag <= 1;
						minuteCount := 0;
						hourCount := hourCount + 1;
						if(hourCount >= 24)then			--达到1day
							hourCount := 0;
						end if;
					end if;
				end if;
			end if;
			timeValue(0) <= secondCount mod 10;
			timeValue(1) <= secondCount/10;
			timeValue(2) <= 15;
			timeValue(3) <= minuteCount mod 10;
			timeValue(4) <= minuteCount/10;
			timeValue(5) <= 15;
			timeValue(6) <= hourCount mod 10;
			timeValue(7) <= hourCount/10;
		end if;
		if(keyFlag = 1)then								--按键扫描
			case keyState is
				when KS0 =>
					if(KEY_IN /= "0000")then
						keyState := KS1;
					else
						outIndex := outIndex + 1;
						if(outIndex >= 4)then
							outIndex := 0;
						end if;
					end if;
				when KS1 =>
					if(KEY_IN /= "0000")then
						keyState := KS2;
						keyInBak <= KEY_IN;
					else
						keyState := KS0;
					end if;
				when KS2 =>
					if(KEY_IN = "0000")then
						keyState := KS3;
					end if;
				when KS3 =>
					if(KEY_IN = "0000")then									--辨别按键
						case conv_integer(keyInBak&keyOutBak) is						
							when 2#00010001# =>								--0
								temp := 0;
							when 2#00010010# =>								--1
								temp := 1;
							when 2#00010100# =>								--2
								temp := 2;
							when 2#00011000# =>								--3
								temp := 3;
							when 2#00100001# =>								--4		
								temp := 4;
							when 2#00100010# =>								--5
								temp := 5;
							when 2#00100100# =>								--6
								temp := 6;
							when 2#00101000# =>								--7
								temp := 7;
							when 2#01000001# =>								--8
								temp := 8;
							when 2#01000010# =>								--9
								temp := 9;
							when 2#01000100# =>								--A
								temp := 10;
							when 2#01001000# =>								--B
								temp := 11;
							when 2#10000001# =>								--C
								temp := 12;
							when 2#10000010# =>								--D
								temp := 13;
							when 2#10000100# =>								--E
								temp := 14;
							when 2#10001000# =>								--F
								temp := 15;
							when others =>
								temp := 0;
						end case; 
						keyState := KS0;
						if(temp = 10)then									--按下A键，时钟加1
							hourCount := hourCount + 1;
							if(hourCount >= 24)then
								hourCount := 0;
							end if;
						elsif(temp = 11)then								--按下B键，时钟减1
							if(hourCount = 0)then
								hourCount := 24;
							end if;
							hourCount := hourCount - 1;
						elsif(temp = 12)then								--按下C键，分钟加1
							minuteCount := minuteCount + 1;
							if(minuteCount >= 60)then
								minuteCount := 0;
							end if;
						elsif(temp = 13)then								--按下D键，分钟减1
							if(minuteCount = 0)then
								minuteCount := 60;
							end if;
							minuteCount := minuteCount - 1;
						elsif(temp = 14)then								--按下E键，秒钟加1
							secondCount := secondCount + 1;
							if(secondCount >= 60)then
								secondCount := 0;
							end if;
						elsif(temp = 15)then								--按下F键，秒钟减1
							if(secondCount = 0)then
								secondCount := 60;
							end if;
							secondCount := secondCount - 1;
						end if;							
					else
						KeyState := KS3;
					end if;
				when others =>
					KeyState := KS0;
			end case;
			keyFlag := 0;
		end if;
	end if;
end process;

SegDisplay:process(RST,CLK_6MHz,timeValue)					--数码管显示
variable disCount : integer range 7 downto 0 := 0;			--位选计数
begin
	if(RST = '1')then
		SEG_DATA <= (others =>'0');		
		SEG_CHOOSE <= (others =>'0');
		disCount := 0;
	elsif(rising_edge(CLK_6MHz))then
		case timeValue(disCount) is							--显示数组里面的数据
			when 0 =>								--0
				SEG_DATA <= "00111111";
			when 1 =>								--1
				SEG_DATA <= "00000110";
			when 2 =>								--2
				SEG_DATA <= "01011011";
			when 3 =>								--3
				SEG_DATA <= "01001111";
			when 4 =>								--4		
				SEG_DATA <= "01100110";
			when 5 =>								--5
				SEG_DATA <= "01101101";
			when 6 =>								--6
				SEG_DATA <= "01111101";
			when 7 =>								--7
				SEG_DATA <= "00000111";
			when 8 =>								--8
				SEG_DATA <= "01111111";
			when 9 =>								--9
				SEG_DATA <= "01101111";
			when 10 =>								--A
				SEG_DATA <= "01110111";
			when 11 =>								--B
				SEG_DATA <= "01111100";
			when 12 =>								--C
				SEG_DATA <= "00111001";
			when 13 =>								--D
				SEG_DATA <= "01011110";
			when 14 =>								--E
				SEG_DATA <= "01111001";
			when 15 =>								--横
				SEG_DATA <= "01000000";
			when others =>
				SEG_DATA <= "00111111";
		end case; 
		if(disCount >= 8)then
			disCount := 0;
		end if;
		SEG_CHOOSE <= conv_std_logic_vector(disCount,3);--片选信号
		disCount := disCount + 1;
	end if;
end process;


process(CLK_6MHz,RST)
variable count4Hz : integer range 750000 downto 0 := 0;
begin
	if(RST = '1')then
		delayCount <= 0;
		foutTemp <= '1';
		count4Hz := 0;
		clk4Hz <= '0';
	elsif(rising_edge(CLK_6MHz))then
		delayCount <= delayCount + 1;
		if((delayCount >= delay)and(delay/=16383))then
			foutTemp <= foutTemp xor '1';
			delayCount <= 0;
		elsif(delay = 16383)then
			foutTemp <= '0';
			delayCount <= 0;			
		end if;
		
		count4Hz := count4Hz + 1;							--
		if(count4Hz >= 750000)then							--分频后产生8Hz信号
			count4Hz := 0;
			clk4Hz <= clk4Hz xor '1';							--产生4Hz信号
		end if;
	end if;
	FOUT <= foutTemp;
end process;

process(clk4Hz,RST)
begin
	if(RST = '1')then
		delay <= 16383;
	elsif(rising_edge(clk4Hz))then
		case songData is
			when 15=>
				delay <= 15306;
			when 21=>
				delay <= 11465;
			when 22=>
				delay <= 10216;
			when 23=>
				delay <= 9100;
			when 24=>
				delay <= 8589;
			when 25=>
				delay <= 7653;
			when 26=>
				delay <= 6818;
			when others =>
				delay <= 16383;
		end case;
	end if;
end process;

process(clk4Hz,songStartFlag)
variable count : integer range 255 downto 0 := 0;		
begin	
	if(songStartFlag = 1)then
		if(rising_edge(clk4Hz))then
			count := count + 1;
			if(count >= 64)then 
				count := 0;
				songStopFlag <= 1;
			end if;
			case count is									--两只老虎乐谱
				when 0=>
					songData <= 21;
				when 1=>
					songData <= 21;
				when 2=>
					songData <= 22;
				when 3=>
					songData <= 22;
				when 4=>
					songData <= 23;
				when 5=>
					songData <= 23;
				when 6=>
					songData <= 21;
				when 7=>
					songData <= 21;
				when 8=>
					songData <= 21;
				when 9=>
					songData <= 21;
				when 10=>
					songData <= 22;
				when 11=>
					songData <= 22;
				when 12=>
					songData <= 23;
				when 13=>
					songData <= 23;
				when 14=>
					songData <= 21;
				when 15=>
					songData <= 21;
				when 16=>
					songData <= 23;
				when 17=>
					songData <= 23;
				when 18=>
					songData <= 24;
				when 19=>
					songData <= 24;
				when 20=>
					songData <= 25;
				when 21=>
					songData <= 25;
				when 22=>
					songData <= 25;
				when 23=>
					songData <= 25;
				when 24=>
					songData <= 23;
				when 25=>
					songData <= 23;
				when 26=>
					songData <= 24;
				when 27=>
					songData <= 24;
				when 28=>
					songData <= 25;
				when 29=>
					songData <= 25;
				when 30=>
					songData <= 25;
				when 31=>
					songData <= 25;
				when 32=>
					songData <= 25;
				when 33=>
					songData <= 26;
				when 34=>
					songData <= 25;
				when 35=>
					songData <= 24;
				when 36=>
					songData <= 23;
				when 37=>
					songData <= 23;
				when 38=>
					songData <= 21;
				when 39=>
					songData <= 21;
				when 40=>
					songData <= 25;
				when 41=>
					songData <= 26;
				when 42=>
					songData <= 25;
				when 43=>
					songData <= 23;
				when 44=>
					songData <= 23;
				when 45=>
					songData <= 23;
				when 46=>
					songData <= 21;
				when 47=>
					songData <= 21;
				when 48=>
					songData <= 21;
				when 49=>
					songData <= 21;
				when 50=>
					songData <= 25;
				when 51=>
					songData <= 25;
				when 52=>
					songData <= 21;
				when 53=>
					songData <= 21;
				when 54=>
					songData <= 21;
				when 55=>
					songData <= 21;
				when 56=>
					songData <= 21;
				when 57=>
					songData <= 21;
				when 58=>
					songData <= 15;
				when 59=>
					songData <= 15;
				when 60=>
					songData <= 21;
				when 61=>
					songData <= 21;
				when 62=>
					songData <= 21;
				when 63=>
					songData <= 21;
				when others =>
					songData <= 0;
			end case;
		end if;
	else
		count := 0;
		songData <= 0;
		songStopFlag <= 0;
	end if;
end process;
end;