clock.vhd

vhdl实现时钟和闹钟功能

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
ENTITY clock IS
 PORT(clk:      IN STD_LOGIC;            --system clock,1hz
      settime:  IN STD_LOGIC;            --recivedfrom "control" module
      weekset:  IN INTEGER RANGE 1 TO 8; --time from "control" module
      hourhset: IN INTEGER RANGE 0 TO 2; 
      hourlset: IN INTEGER RANGE 0 TO 9;
      minhset:  IN INTEGER RANGE 0 TO 5;
      minlset:  IN INTEGER RANGE 0 TO 9;
      sechset:  IN INTEGER RANGE 0 TO 5;
      seclset:  IN INTEGER RANGE 0 TO 9;
      weekdis:  OUT INTEGER RANGE 1 TO 8; --time to be sent to "display" module
      hourhdis: OUT INTEGER RANGE 0 TO 2; --time from "control" module
      hourldis: OUT INTEGER RANGE 0 TO 9; 
      minhdis:  OUT INTEGER RANGE 0 TO 5;
      minldis:  OUT INTEGER RANGE 0 TO 9;
      sechdis:  OUT INTEGER RANGE 0 TO 5;
      secldis:  OUT INTEGER RANGE 0 TO 9);
END clock;
ARCHITECTURE archi OF clock IS
  SIGNAL seclow,minlow,hourlow: INTEGER RANGE 0 TO 9;
  SIGNAL sechigh,minhigh: INTEGER RANGE 0 TO 5;
  SIGNAL hourhigh: INTEGER RANGE 0 TO 2;
  SIGNAL week: INTEGER RANGE 1 TO 8;
BEGIN
  secldis<=seclow;
  sechdis<=sechigh;
  minldis<=minlow;
  minhdis<=minhigh;
  hourldis<=hourlow;
  hourhdis<=hourhigh;
  weekdis<=week;
normal_run:      --this process finishes normal time running
  PROCESS(clk,settime)
  BEGIN
         IF settime='1' THEN
            seclow<=seclset;
            sechigh<=sechset;
            minlow<=minlset;
            minhigh<=minhset;
            hourlow<=hourlset;
            hourhigh<=hourhset;
            week<=weekset;
         ELSE
            IF clk='1' AND clk'event THEN
               IF seclow=9 THEN
                  seclow<=0;
                  IF sechigh=5 THEN
                     sechigh<=0;
                     IF minlow=9 THEN
                        minlow<=0;
                        IF minhigh=5 THEN
                           minhigh<=0;
                           IF hourlow=9 THEN
                              hourlow<=0;
                              hourhigh<=hourhigh+1;
                           ELSIF hourlow=3 and hourhigh=2 THEN
                              hourhigh<=0;
                              hourlow<=0;
                              IF week=8 THEN
                                 week<=1;
                              ELSIF week=6 THEN
                                    week<=8;
                              ELSE week<=week+1;
                              END IF;
                           ELSE
                              hourlow<=hourlow+1;
                           END IF;
                        ELSE
                           minhigh<=minhigh+1;
                        END IF;
                     ELSE
                        minlow<=minlow+1;
                     END IF;
                  ELSE
                     sechigh<=sechigh+1;
                  END IF;
               ELSE
                  seclow<=seclow+1;
               END IF;
            END IF;
         END IF;
       END PROCESS;
END archi;