EDA实验报告
Laboratory Exercise 4
Traffic-light controller
杨本栋
学号：201400800145 2014级电子一班
2016年5月12日
一、实验要求
1.当复位时，学术路绿灯亮，文化路红灯亮。
2.每5秒钟，传感器检测一次两条路是否有人。只要学术路有人，交通灯就不变化；当学术路没人时，亮5秒钟黄灯后变红灯，文化路变绿灯；当学术路有人时，文化路同样有5秒钟黄灯的转换过程；当两条路都没人时，学术路绿灯。
二、源代码
顶层实体——traffic_led
entity traffic_led is port ( clk_all: in std_logic; rst_all: in std_logic; a,c: in std_logic; ag,ay,ar,cg,cy,cr: out std_logic ); end entity;
architecture bhv of traffic_led is component traffic_ctrl is port (clk,rst,ta,tc: in std_logic; ga,gc,ra,rc,ya,yc : out std_logic); end component traffic_ctrl; component count_5s is port (clk,rst: in std_logic; cout : out std_logic); end component count_5s;
signal check : std_logic;
begin u1 :count_5s port map(clk_all ,rst_all,check); u2 :traffic_ctrl port map(check ,rst_all,a,c,ag,cg,ar,cr,ay,cy); end bhv;
元件1——traffic_ctrl(交通灯状态转换)
library ieee;
use ieee.std_logic_1164.all;
entity traffic_ctrl is port (
clk: in std_logic; rst: in std_logic; ta,tc: in std_logic; ga,gc,ra,rc,ya,yc: out std_logic ); end entity;
architecture bhv of traffic_ctrl is type states is (s0,s1,s2,s3); signal cs, next_state: states :=s0; begin com: process(ta,tc) begin case cs is when s0 => ga<='1';ra<='0';ya<='0'; gc<='0';rc<='1';yc<='0'; if ta='0' and tc='1' then next_state<=s1; else next_state<=s0; end if; when s1 => ga<='0';ra<='0';ya<='1'; gc<='0';rc<='1';yc<='0'; next_state<=s2; when s2 => ga<='0';ra<='1';ya<='0'; gc<='1';rc<='0';yc<='0'; if ta='0' and tc='1' then next_state<=s2; else next_state<=s3; end if; when s3 => ga<='0';ra<='1';ya<='0'; gc<='0';rc<='0';yc<='1'; next_state<=s0; when others => ga<='1';ra<='0';ya<='0'; gc<='0';rc<='1';yc<='0'; cs<=s0; end case;
end process com;
reg: process(clk,rst) begin if rst='0' then cs<=s0; elsif clk'event and clk='1' then cs<=next_state; end if; end process reg; end bhv;
元件2——count_5s（计时器5秒，每五秒发一个脉冲，50MHz晶振）
entity count_5s is port ( clk: in std_logic; rst: in std_logic; cout:out std_logic ); end entity;
architecture bhv of count_5s is
signal q: integer range 250000000 downto 0 ; begin process(clk,rst) begin if rst='0' then cout<='0';q<=0; elsif clk'event and clk='1' then q<=q+1; end if; if q=249999999 then cout<='1';q<=0; else cout<='0'; end if; end process; end architecture;
电子设计自动化交通灯设计实验报告
