Interrupt Service Routine (ISR)

This document describes interrupt service routines as used by device drivers.

An ISR is a static function that will be executed when an interrupt occurs on the interrupt source bound to the ISR.

// Interrupt service routines
static void UartIsr(TAny* aParam);

An ISR performs the actions necessary to service the event of the peripheral that generated the interrupt and to remove the condition that caused it to interrupt. It queues a DFC to do the required processing. It disables the interrupts and FIQs on ARM, if required, to handle the interrupt, and enables them before leaving. It can also disable the source of the interrupt that it is servicing.