clearing data memory
initializing hardware reentrant stack pointers
Enabling on-chip external data memory
and match our file to the Target Hardware (for most CPU variants)

But nowwwww, without adding it in my code i could see the micro working fine.
so getting back to what u have said ..
will there be chances for any problem to get arise for having not added the startup code..

If not above... i would like to know the exact use of adding it
to any application.