Nios® V Processor: Lockstep Implementation

ID 833274
Date 10/07/2024
Public
Document Table of Contents

3.3.2. Injecting Fault

The fRSmartComp features two types of hardware fault injection facilities,

  1. Root Fault injection – Performed near the logic where the safety mechanism can detect the error. As the reset scenarios describe, a specific sequence is needed to restart the CPUs and the fRSmartComp after the Root Fault Injection.
  2. Alarm Fault injection – Performed near the alarm outputs. It can be activated and deactivated at any time (without the need for a specific restart sequence).

In other words, the Root Fault injection brings the fRSmartComp into the FCS state where an error has been detected. Conversely, the Alarm Fault injection leaves the fRSmartComp in a functional OD state (no real error detected), although the alarm outputs are forced to be activated. You can decide to adopt the correct fault injection mode according to the system-level integration test strategy.