hi,
i want to use int0 of 8051.for that i write the below mension code and connect to p3.2 to the square wave of 2 volt, but i could not get the interrupt.
the code as follows:
.org 0000h
sjmp main
.org 0003h
acall display
reti
main: mov sp,#30h
mov dptr,#0ff03h
mov a,#80h
movx @dptr,a
mov dptr,#0ff00h
setb tcon.0
mov ie,#81h
here: sjmp here

display: mov a,#0ffh
movx @dptr,a
mov r3,#0ffh
d1: djnz r3,d1
mov a,#00h
movx @dptr,a
mov r1,#0ffh
d2: djnz r1,d2
ret
i use 8255 port A for output purpose.

please help me.
bye
RITESH