;“探索式”  串行口擴(kuò)展并口實(shí)驗(yàn)
;
;文件名：MCS51\C05.ASM
        ORG  0000H


        MOV SCON,#0             ;置串行通訊為方式0
        MOV DPTR,#DATE          ;字形碼首址送 DPTR
MAIN:
        MOV R0,#0h               ;顯示字符從0-F
MAIN1:
        MOV A,R0
        MOVC A,@A+DPTR
    ;    CPL A
        MOV SBUF,A
WAIT:   JNB TI,WAIT
        CLR TI
        INC R0
        MOV A,#05H              ;置延時(shí)初值,延時(shí)1ms
        ACALL DELAY             ;調(diào)用延時(shí)子程序
        CJNE R0,#10H,MAIN1
        AJMP MAIN
DELAY:                ;延時(shí)1ms子程序
        MOV R7,2      ;500us*2=1ms
DLY0:
        MOV R6,50    ;2us*250=500us
        DJNZ R6,$
        DJNZ R7,DLY0
        DJNZ ACC,DELAY
        RET
DATE:
        DB 0C0H,0F9H,0A4H,0B0H,099H,92H,82H,0F8H
        DB 80H,90H,88H,83H,0C6H,0A1H,86H,8EH
        END