library ieee; 
use ieee.std_logic_1164.all; 
use ieee.std_logic_arith.all; 
use ieee.std_logic_unsigned.all; 
entity exp18 is 
port( Clk : in std_logic; --時鐘輸入 
Rst : in std_logic; --復位輸入 
R1,R2 : out std_logic; --紅燈輸出 
Y1,Y2 : out std_logic; --黃燈輸出 
G1,G2 : out std_logic; --綠燈輸出 
Display : out std_logic_vector(7 downto 0); --七段碼管顯示輸出 
SEG_SEL : buffer std_logic_vector(2 downto 0) ); --七段碼管掃描驅(qū)動 
end exp18; 
architecture behave of exp18 is 
signal Disp_Temp : integer range 0 to 15; 
signal Disp_Decode : std_logic_vector(7 downto 0); 
signal SEC1,SEC10 : integer range 0 to 9; 
signal Direction : integer range 0 to 15; 
signal Clk_Count1 : std_logic_vector(9 downto 0); --產(chǎn)生0.5Hz時鐘的分頻計數(shù)器 
signal Clk1Hz : std_logic; 
signal Dir_Flag : std_logic; --方向標志 
begin 
process(Clk) 
begin 
if(Clk'event and Clk='1') then 
if(Clk_Count1<1000) then 
Clk_Count1<=Clk_Count1+1; 
else 
Clk_Count1<="0000000001"; 
end if; 
end if; 
end process; 
Clk1Hz<=Clk_Count1(9); 
process(Clk1Hz,Rst) 
begin 
if(Rst='0') then 
SEC1<=0; 
SEC10<=2; 
Dir_Flag<='0'; 
elsif(Clk1Hz'event and Clk1Hz='1') then 
if(SEC1=0) then 
SEC1<=9; 
if(SEC10=0) then 
SEC10<=1; 
else 
SEC10<=SEC10-1; 
end if; 
else 
SEC1<=SEC1-1; 
end if; 
if(SEC1=0 and SEC10=0) then 
Dir_Flag<=not Dir_Flag; 
end if; 
end if; 
end process; 

process(Clk1Hz,Rst) 
begin 
if(Rst='0') then 
R1<='1'; 
G1<='0'; 
R2<='1'; 
G2<='0'; 
else --正常運行 
if(SEC10>0 or SEC1>3) then 
if(Dir_Flag='0') then --橫向通行 
R1<='0'; 
G1<='1'; 
R2<='1'; 
G2<='0'; 
else 
R1<='1'; 
G1<='0'; 
R2<='0'; 
G2<='1'; 
end if; 
else 
if(Dir_Flag='0') then --橫向通行 
R1<='0'; 
G1<='0'; 
R2<='1'; 
G2<='0'; 
else 
R1<='1'; 
G1<='0'; 
R2<='0'; 
G2<='0'; 
end if; 
end if; 
end if; 
end process; 

process(Clk1Hz) 
begin 
if(SEC10>0 or SEC1>3) then 
Y1<='0'; 
Y2<='0'; 
elsif(Dir_Flag='0') then 
Y1<=Clk1Hz; 
Y2<='0'; 
else 
Y1<='0'; 
Y2<=Clk1Hz; 
end if; 
end process; 
process(Dir_Flag) 
begin 
if(Dir_Flag='0') then --橫向 
Direction<=10; 
else --縱向 
Direction<=11; 
end if; 
end process; 
process(SEG_SEL) 
begin 
case (SEG_SEL+1) is 
when "000"=>Disp_Temp<=Direction; 
when "001"=>Disp_Temp<=Direction; 
when "010"=>Disp_Temp<=SEC10; 
when "011"=>Disp_Temp<=SEC1; 
when "100"=>Disp_Temp<=Direction; 
when "101"=>Disp_Temp<=Direction; 
when "110"=>Disp_Temp<=SEC10; 
when "111"=>Disp_Temp<=SEC1; 
end case; 
end process; 
process(Clk) 
begin 
if(Clk'event and Clk='1') then --掃描累加 
SEG_SEL<=SEG_SEL+1; 
Display<=Disp_Decode; 
end if; 
end process; 
process(Disp_Temp) --顯示轉(zhuǎn)換 
begin 
case Disp_Temp is 
when 0=>Disp_Decode<="00111111"; --'0' 
when 1=>Disp_Decode<="00000110"; --'1' 
when 2=>Disp_Decode<="01011011"; --'2' 
when 3=>Disp_Decode<="01001111"; --'3' 
when 4=>Disp_Decode<="01100110"; --'4' 
when 5=>Disp_Decode<="01101101"; --'5' 
when 6=>Disp_Decode<="01111101"; --'6' 
when 7=>Disp_Decode<="00000111"; --'7' 
when 8=>Disp_Decode<="01111111"; --'8' 
when 9=>Disp_Decode<="01101111"; --'9' 
when 10=>Disp_Decode<="01001000"; --'=' 
when 11=>Disp_Decode<="00010100"; --'||' 
when others=>Disp_Decode<="00000000"; --全滅 
end case; 
end process; 
end behave;