fasheng.vhd

乐曲发生的程序设计,正确,是我们老师给我们的,大家看看吧

library ieee;
use ieee.std_logic_1164.all;

entity fasheng is
port(a:in integer range 0 to 5102;
     clk:in std_logic;
    w:out std_logic;
    v:out std_logic);

end;

architecture fashengb of fasheng is
begin
process(clk,a)
   
      variable b,d: std_logic;
     
      variable c: integer range 0 to 5102;
         begin
     if clk'event and clk='1' then
         if b='0' then
            c:=a;
            b:='1';
         elsif c=0 then
            b:='0';
            d:=not d;
            else
            c:=c-1;
         end if;
end if;
          w<=d;
		v<=d;
      end process;
end fashengb;