10-9-1.asm

书籍8051入门篇

;10-9-1.ASM
$MOD51
	ORG	0000H
	SJMP	START
	ORG	0023H
	SJMP	SERIAL
;
	ORG 	0030H
START:	MOV	TMOD,#21H
	MOV	TH1,#0FDH
	SETB	TR1
	MOV	SCON,#50H
	SETB	ES
	SETB	EA
	SETB	TI
STOP:	CPL	P1.0
	SJMP 	STOP
;
SERIAL:	CPL	P1.1
	JNB	TI,EXIT
	CLR	TI
	MOV	A,#31H
	MOV	SBUF,A
	ACALL	DELAY
EXIT:	CPL	P1.1
	RETI
;
DELAY:	MOV	R0,#0
	DJNZ	R0,$
	RET
	END