ch12_s7.asm

51单片机基础篇 对于有一定基础的人看看 包含书中所以的源代码

     ;PROGRAM NAME S7.ASM
     ;TEST SERIAL PORT(MODE 2)
     ;
     BUZZER		REG	P3.4
     LED		REG	P3.7
     ;			
     			ORG	0000H
     RESET		MOV	R0,#00H
     			DJNZ	R0,$
     			CLR	LED
     			CLR	BUZZER
     ;			
     	 		MOV	SCON,#10010000B  	;T/R,1START BIT
     							;8 BITDATA,1TB8,1STOP BIT
　　　			MOV	PCON,#80H		;SMOD=1
     START		SETB	P1.0			;SYNC SIGNAL FOR SCOPE
     			CLR	TI			;MONITOR TxD FROM SCOPE
     			SETB	TB8			;BIT7=1
　　　			MOV	A,#31H			;ASCII'1'
     			MOV	SBUF,A	
     WAIT1		JNB	TI,WAIT1
     			CLR	P1.0			;SYNC SIGNAL FOR SCOPE
     			CLR	TI
     			CLR	TB8			;BIT7=0
     			MOV	A,#31H
     			MOV	SBUF,A
     WAIT2		JNB	TI,WAIT2
     			SJMP	START			;RE-START
　　;