I had posted the part of the code where i thought i had made the mistake. i assumed that the init was ok. but according to one of peter's post, from a very very long time ago, we need to inculde two reti's in case of a software interrupt. (something i wasn't aware of) i had one small doubt regarding this. the sp will surely change, so will the pc (on the execution of a reti) so where exactly should these reti's be included?

and one more doubt!

is it ok to call, ret and then reti in an ISR?

cheers,

sushil