第1个回答 2017-12-12
ORG 0000H
LJMP MAIN
ORG 0003H
LJMP EXT0
ORG 0013H
LJMP EXT1
ORG 001BH
LJMP T1ISR
ORG 0030H
MAIN:
MOV TMOD,#10H
MOV TH1,#HIGH(65536-50000)
MOV TL1,#LOW(65536-50000)
SETB TR1
SETB ET1
SETB EA
SETB EX0
SETB EX1
SETB IT0
SETB IT1
SETB PX1
CLR PX0
MOV A,#0FEH
MOV R2,#0
MOV R3,#20
MOV B,#0
SJMP $
EXT0:
MOV R2,#1
RETI
EXT1:
MOV R2,#2
RETI
T1ISR:
CLR TR0
MOV TH1,#HIGH(65536-50000)
MOV TL1,#LOW(65536-50000)
SETB TR1
DJNZ R2,T1E
MOV R2,#20
CJNE R2,#0,T101
PUSH ACC
MOV A,B
CPL A
MOV P0,A
MOV B,A
POP ACC
RETI
T101:
CJNE R2,#1,T102
MOV P0,A
RL A
RETI
T102:
MOV P0,A
RR A
T1E:
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