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;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY miaobiao IS
PORT(CLK,EN,RESET :IN STD_LOGIC;             --时钟频率要求100HZ
     SEC01L,SEC01R :OUT INTEGER RANGE 0 TO 9; --0.01秒的左右显示位
     SECL, SECR    :OUT INTEGER RANGE 0 TO 9; --秒的左右显示位
     MINL ,MINR    :OUT INTEGER RANGE 0 TO 9 --分的左右显示位
     );
END ENTITY miaobiao;
ARCHITECTURE ART OF miaobiao IS
     SIGNAL SEC01T:INTEGER RANGE 0 TO 99;
     SIGNAL SECT  :INTEGER RANGE 0 TO 59;
     SIGNAL MINT  :INTEGER RANGE 0 TO 59;
     BEGIN
     PROCESS(CLK,EN,RESET) IS
       BEGIN
         IF(RESET='1') THEN
             SEC01T<=0;
             SECT <=0;
             MINT <=0;
         ELSIF(CLK'EVENT AND CLK='1')THEN
              IF(EN='1') THEN
                  IF(SECT=59 AND SEC01T=99) THEN
                        SEC01T<=0;
                        SECT<=0;
                        MINT<=MINT+1;
                   ELSIF(SEC01T=99)    THEN
                        SEC01T<=0;
                        SECT<=SECT+1;
                        MINT<=MINT;
                   ELSE
                        SEC01T<=SEC01T+1;
                        SECT<=SECT;
                        MINT<=MINT;
                   END IF;
                END IF;
            END IF;
     END PROCESS;
   SEC01L<=SEC01T /10;
   SEC01R<=SEC01T REM 10;
   SECL<=SECT /10;
   SECR<=SECT REM 10;
   MINL<=MINT /10;
   MINR<=MINT REM 10;
END ARCHITECTURE ART;