and1.vhd

来自「用EDA技术来实现LCD文字的显示功能!...」· VHDL 代码 · 共 29 行

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity AND1 is port 
   (HZSEL,CR:  in std_logic;
    AD7,AD6,AD5,AD4:  out std_logic);
end;
architecture ARC_AND1 of AND1 is
   signal  dou:  std_logic_vector(3 downto 0);
   begin
      AD7<=dou(3);
      AD6<=dou(2);
      AD5<=dou(1);
      AD4<=dou(0);
process(HZSEL,CR)
   begin
   if(CR='0')then
      dou<="0000";
   elsif(HZSEL'event and HZSEL='1')then
           if(dou="1010")then
               dou<="0000";
           else
               dou<=dou+1;
           end if;
        end if;
   end process;
end ARC_AND1;