Nios® V Processor: Lockstep Implementation

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

2.5.1. ALARMS

Utilize the Alarms feature to actively monitor and identify any errors that may occur, allowing timely intervention and resolution. The fRSmartComp generates several kinds of alarms, emanating from the various safety mechanisms of the fRSmartComp. Alarms are sticky, i.e. once the corresponding faulty condition is detected, the alarm is generated and remains asserted until a specific clear or reset action is issued.
The following table shows the list of alarms with their meaning (the detected event and the corresponding activated alarm) and the related default alarm severity.
Table 12.  List of ALARMs
Alarm Description Related Features Default Severity
ALARM0 Mismatch detection alarm from the Comparators (CPU outputs mismatch) when the fRSmartComp is in DISABLED state DCLSM - Comparator ERROR
ALARM1 Mismatch detection alarm from the Comparators (CPU outputs mismatch) when the fRSmartComp is not in DISABLED state DCLSM - Comparator WARNING
ALARM2 Detection alarm from the Comparator Self-diagnostic DCLSM - Comparator self-diagnostic WARNING
ALARM3 After comparator self-diagnostic processing, the problem is due to the fRSmartComp. DCLSM - Comparator self-diagnostic WARNING
ALARM4 After comparator self-diagnostic processing, the problem is due to both CPU and fRSmartComp. DCLSM - Comparator self-diagnostic ERROR
ALARM16 Timeout alarm Error Controller – Timeout ERROR
ALARM17 Number of ENABLE commands exceeds counter threshold Error Controller – ENABLE counter ERROR
ALARM19
  • Usage rules violation (e.g. wrong key)
  • Self-Diagnostic (internal diagnostics)
Specialized safety mechanisms ERROR

Others

Idle ALARMs

(ALARM5 to ALARM15, ALARMS18 and ALARM20 to ALARM23)

N/A N/A

The following table describes how you can read the ALARM.

Table 13.  Reading the ALARM
Interface Actions
Configuration Interface Reading the ERRCTRL_ALL_ALARMS_PRIOR_AFI register. This shows the current active alarms before the Alarm Fault Injection
Configuration Interface Reading the ERRCTRL_FNGIALARMS register. This shows the currently active alarms after the Alarm Fault Injection.
fRNET Interface Reading the FRNET_GI_ALARMS[23:0] primary output shows the alarms after the Alarm Fault Injection.