n11-1-1.asm

书籍8051入门篇

;N11-1-1.ASM
$MOD51
PROGRAM_START	EQU	0000H
TIMER1		EQU	20H			;MODE 2
TIMER2		EQU	00H			;MODE 0
VTMODE		EQU	TIMER1 OR TIMER2
B9600		EQU	0FDH
B4800		EQU	0FAH
B2400		EQU	0F4H
B1200		EQU	0E8H
BAUD_RATE 	EQU	B9600			;9600 b/s
SCOPE		EQU	P1.0
;
		ORG	PROGRAM_START
START:		MOV	TMOD,#VTMODE		
		MOV	TH1,#BAUD_RATE		
		SETB	TR1			
		MOV	SCON,#50H		
		SETB	SCOPE			
;
LOOP:		CLR	TI			
		MOV	A,#31H			
		CPL	SCOPE		
		MOV	SBUF,A			
;
WAIT:		JNB	TI,WAIT			
		CPL	SCOPE			
		ACALL	DELAY			
		SJMP	LOOP			
;
DELAY:		MOV	R0,#00H			
		DJNZ	R0,$
		RET
		END