单片机数码管数字来回显示问题

[SHMessi10]

MAIN: JC DIS1
JNC DIS2
LJMP MAIN

DIS1:
MOV R0,#70H
L1: LCALL DIS
LCALL DELAY
INC R0
MOV A,R3
RL A
MOV R3,A
DJNZ 4FH,L1
MOV 4FH,#8
MOV R0,#70H
RET


DIS: MOV A,R3
MOV DPTR,#7002H
MOVX @DPTR,A
MOV A,@R0
MOV DPTR,#TAB
MOVC A,@A+DPTR
MOV DPTR,#7001H
MOVX @DPTR,A
RET

DIS2: MOV R3,#0FEH
MOV R0,#50H
L2: LCALL DIS
LCALL DELAY
INC R0
MOV A,R3
RL A
MOV R3,A
DJNZ 4FH,L2
MOV 4FH,#8
MOV R0,#50H
RET



T0: DJNZ R7,GO
MOV R7,#20
CPL C

GO: MOV TH0, #3CH
MOV TL0, #0B0H
T: RETI

要求：先显示1个数 一秒冲另外一个数，1秒钟又显示最开始那个数，两个数字来回显示。