[求助]帮忙看看啊

高手帮忙看看那本人这个小程序哪里出错了
ORG  0000H
MAIN:
     ACALL ZY_A0
     ACALL YY_A1
     ACALL YY_A2
     ACALL YY_A3
     ACALL DELAY

ZY_A0:
       MOV A, #0FEH
       MOV R1, #08H
LOOP0:
       MOV P0, A
       ACALL DELAY
       RL A
       DJNZ R1, LOOP0
YY_A1:
       MOV A, #7FH
       MOV R1, #08H
LOOP1:
       MOV P2, A
       ACALL DELAY
       RR A
       DJNZ R1, LOOP1
YY_A2:
       MOV A, #7FH
       MOV R1, #08H
LOOP2:
       MOV P3, A
       ACALL A
       RR A
       DJNZ R1, LOOP2
YY_A3: 
       MOV A, #7FH
       MOV R1, #08H
LOOP3:
       MOV P1, A
       ACALL DELAY
       RR A
       DJNZ R1, LOOP3
       AJMP MAIN

DELAY:
       MOV R3, #10
   D1:
       MOV R4, #200
   D2:
       MOV R5, #248
   D3:
       DJNZ R5, D3
       NOP
       DJNZ R4, D2
       DJNZ R3, D1
       RET
       END

呵呵，刚开始都会出现这样那样的小毛病。