2、進入中斷後應該是中斷返回(reti)
TSERVE: CPL A
ANL A,#01H
JNZ L1
MOV TH1,#HIGH(-5000)
MOV TL1,#LOW(-5000)
cpl P1.0
RETi
L1: MOV TH1,#HIGH(-12000)
MOV TL1,#LOW(-12000)
RETI
END