DISP:
MOV DPTR, #D_TAB
MOV R0, #30H
MOV R2, #80H
D_LOOP:
MOV A, @R0
MOVC A, @A + DPTR
MOV P0, A
MOV P2, R2
DJNZ R7, $
DJNZ R7, $
INC R0
MOV A, R2
RL A
MOV R2, A
CJNE R2, #80H, D_LOOP
RET
D_TAB:
DB 0C0H, 0F9H, 0A4H, 0B0H, 99H
DB 92H, 82H, 0F8H, 80H, 90H
待显示的内容，在30H~37H。
