tonetaba.vhd

可以轻松实现秒表计数流水灯计数功能控制器

library ieee;
use ieee.std_logic_1164.all;

entity tonetaba is
port(
     index :  in integer range 0 to 15;
     code  : out integer range 0 to 15;
     tone  : out integer range 0 to 16#7ff#);  --"2047";
end tonetaba;

architecture behav of tonetaba is
begin
search:process(index)
begin
case index is
when 0=>tone<=2047;  code<=0; 
when 1=>tone<=773;   code<=1; 
when 2=>tone<=912;   code<=2; 
when 3=>tone<=1036;  code<=3; 
when 5=>tone<=1197;  code<=5; 
when 6=>tone<=1290;  code<=6; 
when 7=>tone<=1372;  code<=7; 
when 8=>tone<=1410;  code<=1; 
when 9=>tone<=1480;  code<=2; 
when 10=>tone<=1542; code<=3; 
when 12=>tone<=1622; code<=5; 
when 13=>tone<=1668; code<=6; 
when 15=>tone<=1728; code<=1; 
when others=>null;
end case;
end process;
end behav;