;PROGRAM NAME S6.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,1 START BIT
                                ;8 BITDATA,1 TB8,1 STOP BIT
        MOV     PCON,#00H       ;SMOD=0
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
;