An interrupt is a hardware mechanism used to inform the CPU that an asynchronous event has occurred

ISR is the kernel service in OS

ISR is used to handle hardware interrupt

NMI (Nonmaskable Interrupt)

Interrupt : is a signal to the processor indicating an event that needs immediate attention

Micrium OS interrupt handlers (ISRs) take over when interrupts occur

The ISR saves CPU registers and calls OSIntEnter() and OSIntExit()

After the ISR, the scheduler decides which takes to run

Micrium OS has a built-in ISR : the kernel’s tick handler

ISR is provided by Micrium OS to handle interrupt from outside hardware