Nios® V Processor: Lockstep Implementation

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ID 833274
Date 10/07/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the Nios® V Processor Lockstep 2. Overview 3. Controlling the Nios® V Processor Lockstep 4. Programming Model 5. Signals, Interfaces, and Build Parameters 6. Using Nios® V Processor Lock Step A. Document Revision History for the Nios® V Processor: Lockstep Implementation B. Appendix
1. About the Nios® V Processor Lockstep x
1.1. Nios® V Processor Lockstep Features
2. Overview x
2.1. Introduction 2.2. Main Principles 2.3. Operating Modes 2.4. Resets 2.5. LOGS Information
2.2. Main Principles x
2.2.1. System Phases 2.2.2. System States 2.2.3. Safety Mechanisms
2.2.2. System States x
2.2.2.1. Transitioning between System States
2.2.3. Safety Mechanisms x
2.2.3.1. Self-Checking Comparator 2.2.3.2. Timeout Timer 2.2.3.3. Enable Counters 2.2.3.4. Specialized Safety Mechanism
2.3. Operating Modes x
2.3.1. NORMAL and SILENT Modes
2.4. Resets x
2.4.1. Resetting CORE 2.4.2. Resetting OPTIONS 2.4.3. Resetting LOGS 2.4.4. Resetting Time Diversity Register
2.5. LOGS Information x
2.5.1. ALARMS 2.5.2. CONTEXT 2.5.3. STATISTICS 2.5.4. Reset LOGS
2.5.1. ALARMS x
2.5.1.1. Configuring Alarm Severity
3. Controlling the Nios® V Processor Lockstep x
3.1. Configuration Interface 3.2. fRNET Interface 3.3. Controlling the Elective Features
3.3. Controlling the Elective Features x
3.3.1. Applying Timeout and Comparator Blind Window 3.3.2. Injecting Fault 3.3.3. Downloading the CPU Software 3.3.4. Debugging the CPU Software using SILENT Mode 3.3.5. Resetting the CPU upon Fault Detection
3.3.1. Applying Timeout and Comparator Blind Window x
3.3.1.1. Timeout 3.3.1.2. Comparator Blind Window 3.3.1.3. Calculating the Blind Window and Timeout Period
3.3.2. Injecting Fault x
3.3.2.1. Root Fault Injection 3.3.2.2. Alarm Fault Injection
3.3.4. Debugging the CPU Software using SILENT Mode x
3.3.4.1. Entering SILENT Mode 3.3.4.2. SILENT Mode Limitation 3.3.4.3. Exiting SILENT Mode
3.3.5. Resetting the CPU upon Fault Detection x
3.3.5.1. Basic Reset Control
4. Programming Model x
4.1. Memory Map 4.2. Configuring fRSmartComp during Run-time 4.3. Unlocking and Locking Registers 4.4. Detailed Register Description
4.1. Memory Map x
4.1.1. Memory Map—Part 1 4.1.2. Memory Map—Part 2 4.1.3. Memory Map—Part 3
4.4. Detailed Register Description x
4.4.1. DCLSM Blind Window Control Register - DCLSM_BWCR 4.4.2. All Alarms’ Prior Alarms’ Fault Injection Register - ERRCTRL_ALL_ALARMS_PRIOR_AFI 4.4.3. INTREQ Configuration Register - ERRCTRL_INTREQ_CONF 4.4.4. Timeout Deadline and Status Register - ERRCTRL_TIMEOUT 4.4.5. Timeout Acknowledgment Register - ERRCTRL_TIMEOUT_ACK 4.4.6. Enable Key fRSmartComp Control Register - ERRCTRL_ENABLE_KEY 4.4.7. Root Fault Injection Control register - ERRCTRL_ROOT_INJ 4.4.8. Alarm Fault Injection Control register - ERRCTRL_ALARM_INJ 4.4.9. Event Mask Configuration register - ERRCTRL_MASKA and ERRCTRL_MASKB 4.4.10. Alarm Routing Configuration register - ERRCTRL_ROUTA and ERRCTRL_ROUTB 4.4.11. Error Controller PGO LOG Reset Control register - ERRCTRL_PGOLOGRST 4.4.12. PGO0 and PGO4 Configuration registers - ERRCTRL_PGO0 and ERRCTRL_PGO4 4.4.13. FN_MODEIN Control Register - ERRCTRL_FNMODEIN 4.4.14. FN_MODEOUT register - ERRCTRL_FNMODEOUT 4.4.15. All Alarms After Fault Injection - ERRCTRL_FNGIALARMS 4.4.16. Error Controller Context Register - ERRCTRL_FNGICTXT4 4.4.17. CMP Mismatch CONTEXT Registers - ERRCTRL_FNGICMPCTXT0 … ERRCTRL_FNGICMPCTXT3 4.4.18. STATISTICS registers: ERRCTRL_FNGISTAT0 and ERRCTRL_FNGISTAT4 4.4.19. State register - ERRCTRL_FNPERIPHGI4
5. Signals, Interfaces, and Build Parameters x
5.1. Configuration Interface 5.2. System Interface 5.3. fRNET Interface 5.4. IP Parameters
5.3. fRNET Interface x
5.3.1. CONFIG 5.3.2. INFO
6. Using Nios® V Processor Lock Step x
6.1. Instantiating Lockstep-Enabled Processor 6.2. Connecting Signals and Interfaces 6.3. Compiling Design 6.4. Implementing Startup Procedure 6.5. Applying Optional Injection for Validation 6.6. Detecting Faults 6.7. Handling Faults (Safety Use Case)
6.2. Connecting Signals and Interfaces x
6.2.1. Connecting Clock and Reset 6.2.2. Connecting Configuration Interface 6.2.3. Connecting System Interface
6.2.1. Connecting Clock and Reset x
6.2.1.1. Clock 6.2.1.2. Reset
6.2.3. Connecting System Interface x
6.2.3.1. Asynchronous Reset Interface 6.2.3.2. CPU Halt and Restart Acknowledgment Interface 6.2.3.3. Silent Mode Interface 6.2.3.4. Output Qualification (TERMS_LEFT and TERMS_RIGHT) 6.2.3.5. Interrupt Request (INTREQ) 6.2.3.6. ALARMS Interfaces 6.2.3.7. Connecting fRNET Interface
6.7. Handling Faults (Safety Use Case) x
6.7.1. UC_01: Standard Fail Safe or No Availability 6.7.2. UC_02: False Positive Avoidance 6.7.3. UC_03: Timeout on System Reset or After Fault Detection
1. About the Nios® V Processor Lockstep
2. Overview
3. Controlling the Nios® V Processor Lockstep
4. Programming Model
5. Signals, Interfaces, and Build Parameters
6. Using Nios® V Processor Lock Step
A. Document Revision History for the Nios® V Processor: Lockstep Implementation
B. Appendix

3.3.1.2. Comparator Blind Window

You can use the Comparator Blind Window to align the two CPUs before the fRSmartComp compares their outputs. During this period, the fRSmartComp comparators’ outputs are masked when the blind window is active.

The Blind Window:

  • Starts from the de-assertion of the CPUs’ asynchronous reset, both at power-on and in the case of a CPU warm reset.
  • Starts when the blind window duration value is changed in the DCLSM_BWCR register, visible from the Configuration Interface.
  • Has a programmable duration in terms of number of clock cycles. By default, the DCLSM_BWCR register sets the duration to the Blind Window Period IP Parameter value. After that, the duration is configurable through the DCLSM_BWCR register.
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