00.asm

51单片机定时器的设计

$MOD52

	ORG	0000H
	LJMP	START

	ORG	0030H
START:	MOV	P1,00H
	SETB	P1.0
	ACALL	DELAY2
	CLR	P1.0
	SETB	P1.1
	ACALL	DELAY2
	CLR	P1.1
	SETB	P1.2
	ACALL	DELAY2
	CLR	P1.2
	SETB	P1.3
	ACALL	DELAY2
	CLR	P1.3
	SETB	P1.4
	ACALL	DELAY2
	CLR	P1.4
	SETB	P1.5
	ACALL	DELAY2
	CLR	P1.5
	SETB	P1.6
	ACALL	DELAY2
	CLR	P1.6
	SETB	P1.7
	ACALL	DELAY2
	CLR	P1.7
	LJMP	START
DELAY2:	MOV	R3,#0FFH
  DL3:	LCALL	DELAY1
	DJNZ	R3,DL3
	RET
DELAY1:	MOV	R1,#0FFH
  DL2:	MOV	R2,#18H
  DL1:	NOP
	NOP
	DJNZ	R2,DL1
	DJNZ	R1,DL2
	RET
	END