code3.vhd.bak

数字密码锁： 1.系统具有预置的初始密码“00000001”。 2.输入密码与预存密码相同时

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity code3 is
port(clk : in std_logic;
     close : in std_logic;--关锁（拨码开关）
     --input : in std_logic;--输入密码
     enter : in std_logic;--密码确认
     modify : in std_logic;--修改密码
     reset : in std_logic;--复位
     coding : in std_logic_vector(7 downto 0);
     oright : out std_logic;
     wrong : out std_logic
    );
end code3;

architecture behave of code3 is
type state_type is( inlock, outlock, changing);
signal state : state_type;
signal input_coding : std_logic_vector(7 downto 0);
signal in_right : std_logic;
signal in_wrong : std_logic;
begin
oright <= in_right;
wrong <= in_wrong;
process(clk,coding,reset,close,enter,state)
begin
if(reset='0') then 
input_coding <= "00000001";
         state <= inlock;
elsif(clk'event and clk='1') then

         case state is
            when inlock =>
                 in_wrong<='1';
                 in_right<='0';
              if(enter = '0' and coding = input_coding) then
                 state<=outlock;
              else
                 state<=inlock;
              end if;
            when outlock =>
                  in_right <= '1';
                  in_wrong <= '0';
                if(close='0') then
                  state<=inlock;
                elsif (modify = '0') then
                  state <= changing;
                else
                  state <= outlock;
               end if;
            
            when changing =>
                if(enter='0') then 
                    input_coding <= coding;
                    state <= outlock;
                else 
                    state <= changing;
                end if;
          end case;
     end if;
  end process;
end behave;