I have tried out the codings, but I found that the interrupt can't "start up". How can I manually start up the interrupt for testing? i had tried

INT REG P3.2
CLR INT

but it doesn't work.

RS REG P2.0
RW REG P2.1
EN REG P2.2
WR REG P3.6
RD REG P3.7
INT REG P3.2
NUM EQU 40H
;
ORG 00H
AJMP START
ORG 03H
AJMP INT0

START: ACALL INIT
ACALL WRITE
SJMP $ ;

INIT: MOV 20H,#0
MOV 21H,#0
MOV NUM,#100
SETB EA
SETB EX0
RET
;

WRITE: MOV A,#00H ;CHANGE WR FROM 0 TO 1
MOV WR,A ;FOR DELAY
MOV A,#FFH ;FOR DELAY
MOV R7,#FFH ;FOR DELAY
MOV A,R7
MOV WR,A
;
READ: MOV A,#FFH ;CHANGE RD FROM 1 TO 0
MOV RD,A ;FOR DELAY
MOV A,#00H ;FOR DELAY
MOV R6,#00H ;FOR DELAY
MOV A,R6
MOV RD,A
MOV A,P0
;
INT0: PUSH A
ACALL READ
DJNZ NUM,S1
MOV NUM,#100
ACALL TRANS
ACALL DISPLAY
S1: ACALL WRITE
POP A
RETI
;