time_24.txt

关于数字钟的实现

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity time_24 is
   port(clk ,clear: in std_logic;
          cout1,cout2:buffer std_logic);
end;
architecture one of time_24 is
  signal counter1: std_logic_vector(9 downto 0);
  signal counter2: std_logic_vector(5 downto 0);
begin
  process(clk,clear)
begin
if  clear='1' then
   counter1 <=(others=>'0');
   counter2 <=(others=>'0');
elsif   
clk'event and clk ='1' then
   if counter1<"11111000111" then
     counter1<=counter1 +1;
       else 
           cout1<=not cout1;
      end if;
   if counter2<"110001" then
     counter2<=counter2 +1;
  else 
   cout2<=not cout2;
   end if;
end if;
end process;
end one;