how to utilize interrupts in arm9 processors..? what is residing inside ISR..?

ISR is a simple routine as normal function. There is a keyword in the SW development guide as chris specified to place it accordingly into the ISR handler address in vector table.

ISR is a simple routine as normal function. There is a keyword in the SW development guide as chris specified to place it accordingly into the ISR handler address in vector table.

Thanks for your reply.

Just to be clear, the __irq keyword will indeed cause the compiler to output object code which can be installed as an IRQ handler (it will modify the rules for saving/restoring registers and change the return address, for instance) but it will not install the function in the vector table. You still need to do that yourself...

Chris