Nios II Classic Processor Reference Guide

ID 683620
Date 10/28/2016
Document Table of Contents Supervisor-Only Instruction

When your system contains an MMU or MPU and the processor is in user mode (status.U = 1), executing a supervisor-only instruction results in a supervisor-only instruction exception. The supervisor-only instructions are initd, initi, eret, bret, rdctl, and wrctl.

This exception is implemented only in Nios® II processors configured to use supervisor mode and user mode. Refer to the "Operating Modes" section of this chapter for more information.