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CALL INCREMENT
CALL OPEN_KEY
RET
$2: A,#00000001B,$3
CJNE DECREMENT
CALL OPEN_KEY
CALL
$3: P1,#00000011B
RET A,P1
OPEN_KEY: A,#00000011B,$1
MOV DELAY_20MS
$1: A,P1
MOV A,#00000011B,$1
CJNE
CALL TH1,#>(2**16-20000)
MOV TL1,#<(2**16-20000)
CJNE TCON,#01000000B
RET TF1,$1
DELAY_20MS:
MOV R0,#00H,$1
MOV
MOV R0
$1:
JNB R0,#0FH,$1
RET
DECREMENT: R0
CJNE
RET
$1:
DEC
RET
INCREMENT:
CJNE
RET
$1:
INC
RET
END