书籍8051入门篇

				;11-17-1.ASM
				$MOD51
					ORG	0000H
					SJMP	START
					ORG	0023H
					SJMP	SERIAL
				;
					ORG	0030H
				START:	MOV	TMOD,#21H
					MOV	TH1,#0FDH
					SETB	TR1
					MOV	SCON,#50H
					MOV	R1,#0
					SETB	ES
					SETB	EA
					SETB	TI
				STOP:	SJMP	STOP
				;
				SERIAL:	JNB	RI,NEXT
					CLR	RI
					MOV	A,SBUF
					CPL	A
					MOV	P1,A
				NEXT:	JNB	TI,EXIT
					CLR	TI
					ACALL	DELAY
					MOV	A,R1
					MOV	SBUF,A
					INC	R1
				EXIT:	RETI
				;
				DELAY:	MOV	R2,#0
				L1:	MOV	R3,#0
					DJNZ	R3,$
					DJNZ	R2,L1
					RET
					END