ORG 0000HLJMP MAINORG 000BHLJMP T0ISR:ORG 0030HMAIN: MOV TMOD,#01H MOV TH0,#HIGH(65536-50000) MOV TL0,#LOW(65536-50000) SETB TR0 SETB ET0 SETB EA MOV A,#0FEH MOV R2,#40 MOV P0,A SJMP $T0ISR: CLR TR0 MOV TH0,#HIGH(65536-50000) MOV TL0,#LOW(65536-50000) SETB TR0 DJNZ R2,T0E MOV R2,#40 RL A MOV P0,AT0E: RETI END