cl_de.vhd

用fpga控制电梯,实现五层电梯的升降控制,运用vhdl编辑程序.

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
entity cl_de is
	port (
		divide:in STD_LOGIC;
        ladd:in std_logic_vector(1 downto 0);	
	    wai_t: out std_logic_vector(2 downto 0);	
		lift:out std_logic_vector(2 downto 0);
		 );
end cl_de;
architecture a of cl_de is
 signal waitfor,liftor:std_logic_vector(2 downto 0);
 begin
  wai_t<=waitfor;
  lift<=liftor;
	process(waitfor,ladd,closex,delayx)
	begin
		if (divide'event and divide='1') then
			if waitfor="000"  then waitfor<="101";
			else
				if (delay='0') then waitfor<=waitfor-1;
				else waitfor<="010";
				end if;
				if (waitfor="001") then 
					if(ladd="11") then liftor<=liftor+1;
					elsif(ladd="10") then liftor<=liftor-1;
					end if;
				end if;
			end if;
		end if;
	end process;
end a;