A51 MACRO ASSEMBLER  DOOR_BELL                                                            07/29/2006 12:43:25 PAGE     1


MACRO ASSEMBLER A51 V8.00
OBJECT MODULE PLACED IN Door Bell.OBJ
ASSEMBLER INVOKED BY: e:\Program Files\Keil\C51\BIN\A51.EXE Door Bell.asm SET(SMALL) DEBUG EP

LOC  OBJ            LINE     SOURCE

  0097                 1     KEY             BIT             P1.7
  0030                 2     LCNT    EQU             30H
  0031                 3     HCNT    EQU             31H
  0033                 4     FLAG    EQU             33H                                                     ;計數(shù)標志
0000                   5                     ORG             00H
0000 800C              6                     SJMP    START
000B                   7                     ORG             0BH                                                     ;中
                             斷入口
000B 020026            8                     LJMP    INT_T0
000E 753000            9     START:  MOV             LCNT,#00H
0011 753100           10                     MOV             HCNT,#00H
0014 C233             11                     CLR             FLAG
0016 758901           12                     MOV             TMOD,#01H
0019 758CFD           13                     MOV             TH0,#(65536-700)/256            ;定時0.7毫秒
001C 758A44           14                     MOV             TL0,#(65536-700)MOD 256
                      15     ;S1:            JB              KEY,$                                           ;等待按鍵
                      16     ;               LCALL   DELAY
                      17     ;               JB              KEY,$
001F 75A882           18                     MOV             IE,#82H
0022 D28C             19                     SETB    TR0
                      20     ;               SJMP    S1
0024 80FE             21                     sjmp    $
0026 0530             22     INT_T0: INC             LCNT
0028 E530             23                     MOV             A,LCNT
002A B4640F           24                     CJNE    A,#100,I1
002D 753000           25                     MOV             LCNT,#00H
0030 0531             26                     INC             HCNT
0032 E531             27                     MOV             A,HCNT                                          
0034 B40505           28                     CJNE    A,#05H,I1                                       ;輸出500個周期方波
0037 753100           29                     MOV             HCNT,#00H
003A 0533             30                     INC             FLAG                                            ;計數(shù)標志加
                             1
003C B290             31             I1:     CPL             P1.0
003E E533             32                     MOV             A,FLAG
0040 B40003           33                     CJNE    A,#00H,I2                                       
0043 02005B           34                     LJMP    K1                                                      ;FLAG=0,發(fā)