A51 MACRO ASSEMBLER  8255_1_                                                              07/25/2006 13:11:42 PAGE     1


MACRO ASSEMBLER A51 V8.00
OBJECT MODULE PLACED IN 8255(1).OBJ
ASSEMBLER INVOKED BY: e:\Program Files\Keil\C51\BIN\A51.EXE 8255(1).asm SET(SMALL) DEBUG EP

LOC  OBJ            LINE     SOURCE

0000                   1                     ORG     00H
  7CFF                 2     PORTA   EQU     7CFFH                   ;8255A口地址
  7DFF                 3     PORTB   EQU     7DFFH                   ;8255B口地址
  7EFF                 4     PORTC   EQU     7EFFH                   ;8255C口地址
  7FFF                 5     CADDR   EQU     7FFFH                   ;8255控制字地址
0000 7480              6                     MOV     A,#80H                  ;方式0
0002 907FFF            7                     MOV     DPTR,#CADDR
0005 F0                8                     MOVX    @DPTR,A                 ;設(shè)置8255工作方式
0006 74FE              9     LOOP:   MOV     A,#0FEH         ;設(shè)置顯示碼     
0008 7A08             10                     MOV     R2,#8           ;設(shè)置計(jì)數(shù)值       
000A 907CFF           11     OUTPUT: MOV     DPTR,#PORTA             
000D F0               12             MOVX    @DPTR,A                 ;顯示碼送PA口顯示
000E 1116             13             CALL    DELAY 
0010 23               14                     RL      A                               ;顯示碼數(shù)據(jù)移位
0011 DAF7             15                     DJNZ    R2,OUTPUT
0013 020006           16                     LJMP    LOOP
0016 7E00             17     DELAY:  MOV     R6,#0           ;延時(shí)子程序     
0018 7F00             18             MOV     R7,#0
001A                  19     DELAYLOOP:     
001A DEFE             20                     DJNZ    R6,DELAYLOOP 
001C DFFC             21                     DJNZ    R7,DELAYLOOP
001E 22               22                     RET
                      23             END
A51 MACRO ASSEMBLER  8255_1_                                                              07/25/2006 13:11:42 PAGE     2

SYMBOL TABLE LISTING
------ ----- -------


N A M E             T Y P E  V A L U E   ATTRIBUTES

CADDR. . . . . . .  N NUMB   7FFFH   A   
DELAY. . . . . . .  C ADDR   0016H   A   
DELAYLOOP. . . . .  C ADDR   001AH   A   
LOOP . . . . . . .  C ADDR   0006H   A   
OUTPUT . . . . . .  C ADDR   000AH   A   
PORTA. . . . . . .  N NUMB   7CFFH   A   
PORTB. . . . . . .  N NUMB   7DFFH   A   
PORTC. . . . . . .  N NUMB   7EFFH   A   


REGISTER BANK(S) USED: 0 

ASSEMBLY COMPLETE.  0 WARNING(S), 0 ERROR(S)