请教高手！！DS18B20怎么不工作

只看该作者 · 2010-12-24 13:28

我将生成的HEX文件下载到单片机内，LED只显示8888
是时序问题？
INITDS1820:  SETB TEMPDIN
TEMPDIN为AT89S51与ds18b20的接口
NOP
NOP
CLR TEMPDIN
MOV R6,#0A0H
DJNZ R6,$
MOV R6,#0A0H
DJNZ R6,$
SETB TEMPDIN
MOV R6,#32H
DJNZ R6,$
MOV R6,#3CH
LOOP1820:  MOV C,TEMPDIN
JC INITDS1820OUT
DJNZ R6,LOOP1820
MOV R6,#064H
DJNZ R6,$
SJMP INITDS1820
      RET
INITDS1820OUT:  SETB TEMPDIN
RET
READDS1820:  MOV R7,#08H
SETB TEMPDIN
NOP
NOP
READDS1820LOOP: CLR TEMPDIN
NOP
NOP
NOP
SETB TEMPDIN
MOV R6,#07H
DJNZ R6,$
MOV    C,TEMPDIN
MOV R6,#3CH
DJNZ R6,$
RRC A
SETB TEMPDIN
DJNZ R7,READDS1820LOOP
MOV R6,#3CH
DJNZ R6,$
RET
WRITEDS1820:  MOV R7,#08H
SETB TEMPDIN
NOP
NOP
WRITEDS1820LOP:  CLR TEMPDIN
MOV R6,#07H
DJNZ R6,$
RRC A
MOV TEMPDIN,C
MOV R6,#34H
DJNZ R6,$
SETB TEMPDIN
DJNZ R7,WRITEDS1820LOP
RET
READTEMP:  LCALL INITDS1820
MOV A,#0CCH
LCALL WRITEDS1820
MOV R6,#34H
DJNZ R6,$
MOV A,#44H
LCALL WRITEDS1820
MOV R6,#34H
DJNZ R6,$
RET
READTEMP1:  LCALL INITDS1820
MOV A,#0CCH
LCALL WRITEDS1820
MOV R6,#34H
DJNZ R6,$
MOV A,#0BEH
LCALL WRITEDS1820
MOV R6,#34H
DJNZ R6,$
MOV R5,#09H
MOV R0,#TEMPHEAD
MOV B,#00H
READTEMP2:  LCALL READDS1820
MOV @R0,A
INC R0
READTEMP21:
DJNZ R5,READTEMP2
MOV A,B
JNZ READTEMPOUT
MOV A,TEMPHEAD+0
MOV TEMPL,A
MOV A,TEMPHEAD + 1
MOV TEMPH,A
READTEMPOUT:  RET