control.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 control is
	port (
		up:in STD_LOGIC;
		down:in STD_LOGIC;
		run_stop:in STD_LOGIC;
		wai_t: in std_logic_vector(2 downto 0);	
		lift:in std_logic_vector(2 downto 0);
        ladd: out std_logic_vector(1 downto 0);	
		 );
end control;
architecture a of control is
 begin
	process(up,down,lift,wai_t,run_stop)--该进程完成电梯将来运行状态的判断输出
	begin
		if (run_stop='1') then 
			if (wai_t="101") then
				if ((up or down)="000000") then ladd(1)<='0';
				else
					case lift is
						when "000"=>if ((up(1) or down(1))>'0') then ladd(1)<='0';
							else ladd<="11";
							end if;
						when "001"=>if ((up(2) or down(2))>'0') then ladd(1)<='0';
							elsif(((ladd(0)='1') and ((up(6 downto 3) or down(6 downto 3))>"0000")) or ((up(1) or down(1))='0')) then ladd<="11";
							else ladd<="10";
							end if;
						when "010"=>if ((up(3) or down(3))>'0') then ladd(1)<='0';
							elsif(((ladd(0)='1') and ((up(6 downto 4) or down(6 downto 4))>"000")) or ((up(2 downto 1) or down(2 downto 1))="00")) then ladd<="11";
							else ladd<="10";
							end if;
						when "011"=>if ((up(4) or down(4))>'0') then ladd(1)<='0';
							elsif(((ladd(0)='1') and ((up(6 downto 5) or down(6 downto 5))>"00")) or ((up(3 downto 1) or down(3 downto 1))="000")) then ladd<="11";
							else ladd<="10";
							end if;
						when "100"=>if ((up(5) or down(5))>'0') then ladd(1)<='0';
							elsif(((ladd(0)='1') and ((up(6) or down(6))>'0')) or ((up(4 downto 1) or down(4 downto 1))="0000")) then ladd<="11";
							else ladd<="10";
							end if;
						when others=>null;
					end case;
				end if;
			end if;
			else ladd<="00";
		end if;
	end process;
end a;