ORG 00H RESET: LJMP START ORG 0BH COUNT10: LJMP COUNTO ORG 1BH COUNT11: LJMP COUNT1 ORG 30H START: MOV SP,#50H MOV A,TMOD ANL A,#11110000B ORL A,#00000011B MOV TMOD,A MOV TH0#(256-100) MOV TL0,#(256-200) CLR TF0 CLR TF1 SETB IE.1 SETB IE.3 SETB IE.7 SETB TR0 SETB TR1 CLR P3.5 CLR P3.4 L1: NOP JMP L1 COUNTO: CLR IE.1 CPL P3.5 MOV TL0,#(256-200) SETB IE.1 RETI COUNT1: CLR IE.3 CPL P3.4 MOV TH0,#(256-100) SETB IE.3 RETI END