s12-1.asm

手把手教你学单片机（第2版）实验程序

	ORG 0000H
	LJMP MAIN
	ORG 030H
MAIN:	MOV TMOD,#00H
	MOV TH1,#0F0H
	MOV TL1,#0CH
	MOV IE,#00H
	SETB TR1
LOOP:	JBC TF1,LOOP1
       	AJMP LOOP
LOOP1:	MOV TH1,#0F0H
	MOV TL1,#0CH
	CLR TF1
	CPL P1.7 
	AJMP LOOP
	END