Hello Dear Friends.
Before Any thing i apologize if my english is not god?
This is my problem:

I build telephone set with this features:
for example melody generator,phone book,caller id
and serial transfer for transfering data to computer.
But there is a bug in source code.
when you go to menu section if telephone ringing
an interrupt will be accured.
when ISR is ended i want that program restarted from specific point
for axample 50h.
This is my code

END_ISR:
POP 7
POP 7
POP 7
MOV R7,#50H
PUSH 7
MOV R7,#0H
PUSH 7
SETB P3.3
RETI

org 50h
main:
mov ie,#10000101b

50h ---->>>>>> PC


I thought i could change return address for pc(program counter)
with this code.yes but set is working for 3 times interrupts and
then hang up.I am sure this is for sp(stack pointer)
And I am sure using AT89C55WD can easily
solve this problem.

END_ISR:
sjmp END_ISR

org 50h
main:
mov ie,#10000101b


There fore watch dog flag resets uC.


Can I use AT89C52?
Please Help Me.