t_miaobiao.vhd

实现秒表的功能。能精确到0.01位。最多能计时1个小时。

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY t_miaobiao IS
END ENTITY t_miaobiao;
ARCHITECTURE ARCT OF t_miaobiao IS
    COMPONENT miaobiao IS
          PORT(CLK,EN,RESET:IN STD_LOGIC;
               SEC01L,SEC01R    :OUT INTEGER RANGE 0 TO 9;
               SECL,MINL:OUT INTEGER RANGE 0 TO 7;
               SECR,MINR:OUT INTEGER RANGE 0 TO 9
               );
END COMPONENT miaobiao;
SIGNAL CLK,EN,RESET : STD_LOGIC:='0';
SIGNAL SEC01L,SEC01R: INTEGER RANGE 0 TO 9;
SIGNAL SECL,MINL    : INTEGER RANGE 0 TO 7;
SIGNAL SECR,MINR    : INTEGER RANGE 0 TO 9;
 BEGIN
       CLK<=NOT CLK AFTER 5 MS; 
       RESET<='0','1'AFTER 40 MS,'0' AFTER 100 MS;
    PROCESS
         BEGIN
             EN<='0';
            WAIT FOR 40  MS;
             EN<='1';
             WAIT FOR 500 MS;
             EN<='0';
    END PROCESS;
U1:miaobiao PORT MAP(CLK=>CLK,EN=>EN,RESET=>RESET,
                     SEC01L=>SEC01L,SEC01R=>SEC01R,
                     SECL=>SECL,MINL=>MINL,
                     SECR=>SECR,MINR=>MINR);
END ARCHITECTURE ARCT;