hi vijaya,
actually low level interrupt is the default interrupt when we use 8051 uc.
To work with this we want to set EX0 or EX1 and enable the EA register.
with this we can easily work with the low level external interrupt..
and also vijaya... i am expecting that u r from hyderabad...
if so give me mail for this address
snrao007@rediffmail.com
bye