ORG 00H
LJMP MAIN
ORG 03H
LJMP EXT0
ORG 30H
MAIN:MOV SP , #35H
SETB 1T0
SETB EA
SETB EXT0
MOV A, #01H
LOOP: MOV P, A
LCALL DELAY
RL A
SJMP LOOP
DELAY : MOV R7 #08
L1:MOV R6 #09
DJNZ R6 $
DJNZ R7 L1
RET
ORG 0200H
EXT0: PUSH ACC
SETB PSW
MOV R5, #10
LOOP1:MOV A, 00H
MOV P1, A
LCALL DELAY
CPL A
MOV P1, A
LCALL DELAY
DJNZ R5 LOOP
POP PSW
POP ACC
RET
帮我每个句子翻译下，并说明为什么要用这个。