seg.vhd

这是一个用VHDL语言编写的电梯控制程序

library ieee;
use ieee.std_logic_1164.all;
entity seg is
    port(a:in std_logic_vector(3 downto 1);
         clk:in std_logic;
         q:out std_logic_vector(6 downto 0));
end seg;
architecture seg_arc of seg is
begin
   process(clk)
   begin
      if(clk'event and clk='1')then
         case a is
             when"001"=>q<="0000110";
             when"010"=>q<="1011011";
             when"100"=>q<="1001111";
             when others=>null;
         end case;
       end if;
    end process;
end seg_arc;