基于BASYS2的VHDL程序——交通灯（状态机版）

请尊重作者版权，转载注明源地址：http://www.cnblogs.com/connorzx/p/3694618.html 

使用了状态机，增加了可读性和用户体验。

  1 library IEEE;
  2 use IEEE.STD_LOGIC_1164.ALL;
  3 use IEEE.STD_LOGIC_ARITH.ALL;
  4 use IEEE.STD_LOGIC_UNSIGNED.ALL;
  5 entity main is
  6     Port ( clk : in  STD_LOGIC;
  7            rst : in  STD_LOGIC;
  8            led : out  STD_LOGIC_VECTOR (5 downto 0);
  9            an : out  STD_LOGIC_VECTOR (3 downto 0);
 10            seg : out  STD_LOGIC_VECTOR (6 downto 0));
 11 end main;
 12 
 13 architecture Behavioral of main is
 14 signal sclk: std_logic;
 15 signal now_state,next_state: std_logic_vector(1 downto 0);
 16 signal ledt: std_logic_vector(5 downto 0);
 17 signal led_state: std_logic_vector(5 downto 0);
 18 signal cnt0:integer:=0;
 19 signal cnt1:integer:=0;
 20 signal cnt2:integer:=0;
 21 signal disp_main:integer:=15;
 22 signal disp_branch:integer:=12;
 23 signal display:integer;
 24 signal time_main:integer;
 25 signal time_main_l:integer;
 26 signal time_main_h:integer;
 27 signal time_branch:integer;
 28 signal time_branch_l:integer;
 29 signal time_branch_h:integer;
 30 signal time_long:integer:=12;
 31 constant red_time:integer:=16; 
 32 constant green_time:integer:=12; 
 33 constant yellow_time:integer:=3; 
 34 signal an_sel: integer;
 35 begin
 36 led(0)<=led_state(0);
 37 led(1)<=led_state(1);
 38 led(2)<=led_state(2);
 39 led(3)<=led_state(3);
 40 led(4)<=led_state(4);
 41 led(5)<=led_state(5);
 42 process(clk)
 43 begin
 44     if(clk'event and clk='1') then
 45         if(cnt0=25000000)then
 46             cnt0<=0;
 47             sclk<=not sclk;
 48         else
 49             cnt0<=cnt0+1;
 50         end if;
 51     end if;
 52 end process;
 53 
 54 process(clk)
 55 begin
 56 if(clk'event and clk='1') then
 57     if(cnt2=50000) then
 58         cnt2<=0;
 59           if(an_sel=3)then
 60                 an_sel<=0;
 61           else
 62                 an_sel<=an_sel+1;
 63           end if;
 64     else
 65         cnt2<=cnt2+1;
 66     end if;
 67 end if;
 68 end process;
 69 
 70 process(now_state)
 71 begin
 72 case now_state is
 73     when "00"=>time_long<=green_time;ledt<="010001";next_state<="01";
 74     when "01"=>time_long<=yellow_time;ledt<="100001";next_state<="11";
 75     when "11"=>time_long<=green_time;ledt<="001010";next_state<="10";
 76     when "10"=>time_long<=yellow_time;ledt<="001100";next_state<="00";
 77     when others=>time_long<=green_time;ledt<="010001";next_state<="00";
 78 end case;
 79 end process;
 80 
 81 process(rst,sclk)
 82 begin
 83     if(rst='1') then
 84             now_state<="00";
 85             led_state<="000000";
 86     elsif(sclk'event and sclk='1') then
 87             led_state(0)<=ledt(0);
 88             led_state(1)<=ledt(1);
 89             led_state(2)<=ledt(2);
 90             led_state(3)<=ledt(3);
 91             led_state(4)<=ledt(4);
 92             led_state(5)<=ledt(5);
 93             if(cnt1=time_long) then
 94                     now_state<=next_state;
 95                     cnt1<=0;
 96             else
 97                     cnt1<=cnt1+1;        
 98             end if;       
 99     end if;
100 end process;
101 
102 process(sclk,led_state,rst,cnt1)
103 begin
104 if (rst='1')then
105         disp_main<=red_time;
106         disp_branch<=green_time;
107     elsif(sclk'event and sclk='1') then
108         if(disp_main=0)then
109             if(led_state(0)='1')then
110                 disp_main<=green_time;
111             elsif(led_state(1)='1')then
112                 disp_main<=yellow_time;
113             elsif(led_state(2)='1')then
114                 disp_main<=red_time;
115             end if;
116         else
117             disp_main<=disp_main - 1;
118         end if;
119         if(disp_branch=0)then
120             if(led_state(3)='1')then
121                 disp_branch<=green_time;
122             elsif(led_state(4)='1')then
123                 disp_branch<=yellow_time;
124             elsif(led_state(5)='1')then
125                 disp_branch<=red_time;
126             end if;
127         else
128             disp_branch<=disp_branch - 1;
129         end if;
130     end if;
131 end process;
132 
133 process(an_sel,disp_main,disp_branch)
134 begin
135     time_main<=disp_main;
136     if(time_main>=10)then
137         time_main_h<=1;
138         time_main_l<=time_main-10;
139     else
140         time_main_h<=0;
141         time_main_l<=time_main;
142     end if;
143         time_branch<=disp_branch;
144     if(time_branch>=10)then
145         time_branch_h<=1;
146         time_branch_l<=time_branch-10;
147     else
148         time_branch_h<=0;
149         time_branch_l<=time_branch;
150     end if;
151 case an_sel is
152         when 0=>an<="1110";display<=time_main_l;
153         when 1=>an<="1101";display<=time_main_h;
154         when 2=>an<="1011";display<=time_branch_l;
155         when 3=>an<="0111";display<=time_branch_h;
156         when others=>null;
157 end case;
158 case display is
159           when 0=>seg<=b"0000001";
160           when 1=>seg<=b"1001111";
161           when 2=>seg<=b"0010010";
162           when 3=>seg<=b"0000110";
163           when 4=>seg<=b"1001100";
164           when 5=>seg<=b"0100100";
165           when 6=>seg<=b"0100000";
166           when 7=>seg<=b"0001111";
167           when 8=>seg<=b"0000000";
168           when 9=>seg<=b"0000100";
169           when others=>null;
170 end case;
171 end process;
172 end Behavioral;

 

posted @ 2014-04-27 14:25  connorzx  阅读(744)  评论(0)  编辑  收藏  举报