EDA交通灯设计.doc

LIBRARY IEEE;
USE ;
USE ;
USE ;
ENTITY traffic IS
PORT( clk,urgent : IN STD_LOGIC;
NBR : OUT STD_LOGIC;
NBY : OUT STD_LOGIC;
NBG : OUT STD_LOGIC;
DXR : OUT STD_LOGIC;
DXY : OUT STD_LOGIC;
DXG : OUT STD_LOGIC;
display: BUFFER INTEGER RANGE 30 DOWNTO 0
);
END ENTITY traffic;

ARCHITECTURE bhv OF traffic IS
SIGNAL state,q : STD_LOGIC;
SIGNAL count : INTEGER RANGE 55000 DOWNTO 0;
BEGIN
PROCESS(clk,urgent) BEGIN
IF clk'event AND clk='1' THEN
IF count=55000 THEN count<=0;NBG<='0';NBY<='0';NBR<='0';DXR<='0';DXY<='0';DXG<='0';
ELSE
count<=count+1;
IF urgent='1' THEN state<=urgent;
ELSE state<=q;
IF state='1'THEN NBR<='1';DXR<='1';NBG<='0';NBY<='0';DXY<='0';DXG<='0';q<='1';
ELSE
IF count<20000 AND state='0' THEN NBG<='1';DXR<='1';display<=(26000-count)/1000;
ELSIF count>20000 AND count<25000 AND state='0'THEN NBY<='