Nios II Custom Instruction User Guide

ID 683242
Date 4/27/2020
Document Table of Contents

1. Nios II Custom Instruction Overview

Custom instructions give you the ability to tailor the Nios II processor to meet the needs of a particular application. You can accelerate time critical software algorithms by converting them to custom hardware logic blocks. Because it is easy to alter the design of the FPGA-based Nios II processor, custom instructions provide an easy way to experiment with hardware-software tradeoffs at any point in the design process.

The custom instruction logic connects directly to the Nios II arithmetic logic unit (ALU) as shown in the following figure.

Figure 1. Custom Instruction Logic Connects to the Nios II ALU