EDA实验 红绿灯控制器的设计

library ieee;
use ieee.std_logic_1164.all;
entity yt is
port(clk:in std_logic;
     time_counter:buffer integer range 0 to 49;
 r1,y1,g1,r2,y2,g2:out std_logic);
end entity yt;
architecture one of yt is
Type FSM_ST is (s0,s1,s2,s3);
signal current_state,next_state:FSM_ST;
signal clk1:std_logic;
begin
oneSecond:process(clk)
variable count:integer range 0 to 999_999;
begin
if(clk='1' and clk'event) then
  if count=999_999 then
count:=0;
else count:=count+1;
end if;
if(count<500_000) then
clk1<='0';
else
clk1<='1';
end if;
end if;
end process;
count_time:process(clk1)
begin
if(clk1='1' and clk1'event) then