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SDA24
EQU P3.7
SCLK24 EQU
P3.6
ORG
0000H
AJMP
MAIN
ORG
0030H
MAIN:CLR P3.7
;打开写保护
MOV
DPTR,#TAB
MOV
A,#00H
;读地址
LCALL
RD24
CJNE
A,#10,TT
TT: JNC
TT1
AJMP
TT2
TT1: MOV
A,#00
TT2: MOV
30H,A
MOVC
A,@A+DPTR
CLR
P2.6 ;开数码管
MOV
P0,A ;送显示
MOV
A,30H
INC
A
MOV
B,A
MOV
A,#00H
LCALL
WT24
AJMP
$
TAB: DB
28H,7EH,0A2H,62H,74H,61H,21H,7AH,20H,60H
RD24: PUSH ACC
;读24C02子程序。
SETB SDA24
CLR SCLK24
CALL START24 ;启动
MOV A,#0A0H
CALL SHIFT8 ;移位
CALL ACK ;响应
POP ACC
CALL SHIFT8
CALL ACK
CALL START24
MOV A,#0A1H
CALL SHIFT8
CALL ACK
SETB SDA24
MOV R7,#8
CLR A
SETB SDA24
RD000:
RL A
;8个位
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SETB SCLK24
MOV C,SDA24
MOV ACC.0,C
CLR SCLK24
DJNZ R7,RD000
RET
WT24: PUSH
ACC;写入24C02程序：
SETB SDA24
CLR SCLK24
CALL START24
MOV A,#0A0H
CALL SHIFT8
CALL ACK
POP ACC
CALL SHIFT8
CALL ACK
MOV A,B
CALL SHIFT8
CALL ACK
CALL STOP
CALL DELAY2
RET
START24:CLR SDA24;开始条件
SETB SDA24
SETB SCLK24
CLR SDA24
CLR SCLK24
RET
STOP: CLR
SDA24;停止条件
SETB SCLK24
SETB SDA24
RET
ACK: SETB
SCLK24;应答信号
CLR SCLK24
RET
SHIFT8: MOV R7,#8;读、写数据
SH01: RLC A
MOV SDA24,C
SETB SCLK24
CLR SCLK24
DJNZ R7,SH01
RET
DELAY2: NOP
END
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