Nios® V Processor Software Developer Handbook

ID 743810
Date 10/06/2025
Public
Document Table of Contents

9.3.1. Platform Interrupt Service Routines (Basic) for CLINT & CLIC

Software often communicates with peripheral devices using platform interrupts. When a peripheral asserts its IRQ, it diverts the processor’s normal execution flow. When such an interrupt occurs, an appropriate ISR must handle this interrupt and return the processor to its pre-interrupt state on completion.

When you create a board support package (BSP) project, the build tools include all needed device drivers. You do not need to write HAL ISRs unless you are interfacing to a custom peripheral. For reference purposes, this section describes the framework provided by HAL BSPs for handling platform interrupts.

For examples of HAL ISRs, refer to existing handlers for Altera® components.Developing Programs Using the Hardware Abstraction Layer section.