display.vhd

基于VHDL实现的十字路口交通灯功能

library ieee;
use ieee.std_logic_1164.all;

entity display is
port
(clk:in std_logic;
 shanshuo:in std_logic;
 num:in integer range 0 to 15;
 display:out std_logic_vector(0 to 6));
end;

architecture b_display of display is
signal timeout:integer range 0 to 63;
begin
process(clk)
 begin
   if rising_edge(clk) then
    if(shanshuo='0') then
      timeout<=0;
     else
    if (timeout=63) then
      timeout<=0;
     else
       timeout<=timeout+1;
     end if;
    end if;
if (timeout=31) then
  case num is
when 0=>display<="1111110";
when 1=>display<="0110000";
when 2=>display<="1101101";
when 3=>display<="1111001";
when 4=>display<="0110011";
when 5=>display<="1011011";
when 6=>display<="0011111";
when 7=>display<="1110000";
when 8=>display<="1111111";
when 9=>display<="1110011";
when others=>display<="0000000";
end case;
  else
display<="0000000";
end if;
end if; 
end process;
end;