;FOR    EAT598
;---------------------------------------------------------
D8255   EQU     0F22BH          ;8255命令口地址
D8255A  EQU     0F228H          ;8255 PA口地址
D8255B  EQU     0F229H          ;8255 PB口地址
D8255C  EQU     0F22AH          ;8255 PC口地址
;---------------------------------------------------------
        ORG     0000H
        LJMP    START
        ORG     0100H
START:
        LCALL   DELAY           ;延時
        MOV     DPTR,#D8255
        MOV     A,#82H          ;置8255狀態(tài)
                                ;方式0，PA，PC口輸出，PB口輸入
        MOVX    @DPTR,A
ROTATE:
        MOV     DPTR,#D8255B
        MOVX    A,@DPTR         ;讀開關狀態(tài)
        MOV     DPTR,#D8255C
        MOVX    @DPTR,A         ;點亮對應的LED
        SJMP    ROTATE

DELAY:  MOV     R0,#0H          ;延時子程序
DELAY1: MOV     R1,#0H
        DJNZ    R1,$
        DJNZ    R0,DELAY1
        RET
        END