jtd.vhdl

交通灯控制,在A和B方向各用数码管显示剩余的时间.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

--  Uncomment the following lines to use the declarations that are
--  provided for instantiating Xilinx primitive components.
--library UNISIM;
--use UNISIM.VComponents.all;

entity JTD is
    Port ( clk: in std_logic;
           rst : in std_logic;
		 AXS:   out std_logic_vector(2 downto 0);
           A_R : out std_logic;
           A_Y : out std_logic;
           A_G : out std_logic;
		 A_L : out std_logic;
           B_R : out std_logic;
           B_Y : out std_logic;
           B_G : out std_logic;
		 B_L : out std_logic);
end JTD;

architecture Behavioral of JTD is
   CONSTANT Count_MAX : INTEGER:=59;
   CONSTANT Count_RY  : INTEGER:=4;
   CONSTANT Count_RG  : INTEGER:=24;
   CONSTANT Count_RL  : INTEGER:=14;
   CONSTANT Count_GR  : INTEGER:=34;
   CONSTANT Count_YR  : INTEGER:=4;
   CONSTANT Count_LR  : INTEGER:=14;
   TYPE   LIGHT_STATE IS (RR,GR,YR1,YR2,LR,RG,RY1,RY2,RL);
   SIGNAL CR_STATE: LIGHT_STATE;
   SIGNAL NX_STATE : LIGHT_STATE;
   SIGNAL CT_TIME: INTEGER RANGE 0 TO Count_Max;
   SIGNAL COUNT:   INTEGER RANGE 0 TO Count_Max;
begin
   process(clk,rst,NX_STATE)
   begin
	   if(rst='0') then
	      CR_STATE<=RR;
		 COUNT<=0;
	   elsif(clk'event and clk='1') then
		   if(COUNT=CT_TIME) then
	          CR_STATE<=NX_STATE;
		     COUNT<=0;
		   else
		     COUNT<=COUNT+1;
	    	   end if;
	   end if;
    end process;
    process(CR_STATE)
    begin
         case CR_STATE is
	         when RR=>
		        AXS<="111";
		        A_R<='0';A_G<='1';A_Y<='1';A_L<='1';
			   B_R<='0';B_G<='1';B_Y<='1';B_L<='1';
			   NX_STATE<=GR;
	         when GR=>
		        AXS<="000";
		        A_R<='1';A_G<='0';A_Y<='1';A_L<='1';
			   B_R<='0';B_G<='1';B_Y<='1';B_L<='1';
			   NX_STATE<=YR1;
			   CT_TIME<=Count_GR;
		    when YR1=>
		        A_R<='1';A_G<='1';A_Y<='0';A_L<='1';
			   B_R<='0';B_G<='1';B_Y<='1';B_L<='1';
			      NX_STATE<=LR;
			   CT_TIME<=Count_YR;
		    when LR=>
		        AXS<="001";
			   A_R<='1';A_G<='1';A_Y<='1';A_L<='0';
			   B_R<='0';B_G<='1';B_Y<='1';B_L<='1';
			   NX_STATE<=YR2;
			   CT_TIME<=Count_LR;
		    when YR2=>
		        A_R<='1';A_G<='1';A_Y<='0';A_L<='1';
			   B_R<='0';B_G<='1';B_Y<='1';B_L<='1';
			      NX_STATE<=RG;
			   CT_TIME<=Count_YR;
		    when RG=>
		        AXS<="010"; 
		        A_R<='0';A_G<='1';A_Y<='1';A_L<='1';
			   B_R<='1';B_G<='0';B_Y<='1';B_L<='1';
			   NX_STATE<=RY1;
			   CT_TIME<=Count_RG;
		     when RY1=>
			   
		        A_R<='0';A_G<='1';A_Y<='1';A_L<='1';
			   B_R<='1';B_G<='1';B_Y<='0';B_L<='1';
			      NX_STATE<=RL;
			   CT_TIME<=Count_RY;
		     when RL=>
			   AXS<="011";
		        A_R<='0';A_G<='1';A_Y<='1';A_L<='1';
			   B_R<='1';B_G<='1';B_Y<='1';B_L<='0';
			   NX_STATE<=RY2;
                  CT_TIME<=Count_RL;
			when RY2=>
		        A_R<='0';A_G<='1';A_Y<='1';A_L<='1';
			   B_R<='1';B_G<='1';B_Y<='0';B_L<='1';
			      NX_STATE<=GR;
			   CT_TIME<=Count_RY;

	    end case;
	  end process;
end Behavioral;