15.2 Overview

An interrupt request signals a state change inside a peripheral and can be used to alter the program execution. The peripherals can have one or more interrupts. All interrupts are individually enabled and configured. When an interrupt is enabled and configured, it will generate an interrupt request when the interrupt condition occurs.

The CPU Interrupt Controller (CPUINT) handles and prioritizes the interrupt requests. When an interrupt is enabled and the interrupt condition occurs, the CPUINT will receive the interrupt request. Based on the interrupt’s priority level and the priority level of any ongoing interrupt, the interrupt request is either acknowledged or kept pending until it has priority. After returning from the interrupt handler, the program execution continues from where it was before the interrupt occurred, and any pending interrupts are served after executing one instruction.

The CPUINT offers NMI for critical functions, one selectable high-priority interrupt, and an optional round robin scheduling scheme for normal-priority interrupts. The round robin scheduling ensures servicing all interrupts within a certain amount of time.