Freedom from Interference
Design and verify Freedom from Interference partitioning for mixed-ASIL systems, multi-core processors, and AUTOSAR platforms per ISO 26262-6 and -9.
What You'll Learn
Build complete competency in freedom from interference through structured, progressive learning.
Design FFI Partitioning Architecture
Architect temporal and spatial partitioning strategies that prevent interference between mixed-ASIL software components.
Configure Memory Protection
Specify and verify MPU configurations that enforce spatial isolation between software components of different ASIL levels.
Address Multi-Core FFI Challenges
Identify and mitigate cache sharing, bus contention, and cross-core interrupt interference in multi-core processor designs.
Implement FFI in AUTOSAR
Configure AUTOSAR OS partitions, MemMap, and MemProtection to implement production-grade FFI in automotive software.
Generate FFI Verification Evidence
Plan and execute FFI verification including WCET analysis, fault injection, static analysis, and documentation.
Comply with ISO 26262 Parts 6 and 9
Satisfy all normative FFI requirements from ISO 26262 Parts 6 and 9 with justified partitioning decisions and evidence.
12 Comprehensive Chapters
Each chapter builds your freedom from interference expertise systematically from foundations to advanced application.
FFI Overview
Understand Freedom from Interference: what it means, why it is required, and where it applies in ISO 26262.
ISO 26262 FFI Requirements
Map the specific FFI requirements from ISO 26262 Part 6 (software) and Part 9 (mixed ASIL) with clause references.
Temporal Partitioning
Design time-based partitioning strategies using OS scheduling, time windows, and deadline monitoring.
Spatial Partitioning
Implement memory protection to prevent spatial interference between software components of different ASIL levels.
Communication Partitioning
Partition inter-process and inter-core communication to prevent data corruption across ASIL boundaries.
Data Partitioning
Protect safety-relevant data from corruption by lower-ASIL components using data integrity and access control.
Multi-Core Considerations
Address FFI challenges specific to multi-core processors: cache sharing, bus contention, and cross-core interrupts.
AUTOSAR Integration
Configure AUTOSAR OS, MemMap, and MemProtection modules to implement FFI partitioning in production software.
Analysis Techniques
Apply formal and semi-formal analysis methods to demonstrate FFI: worst-case execution time, code review, static analysis.
Verification & Evidence
Generate verification evidence for FFI partitioning: test strategies, fault injection, and documentation requirements.
Common Challenges
Recognize and resolve frequent FFI implementation challenges including false positives, performance impacts, and tool limitations.
Best Practices
Apply proven best practices for FFI architecture design, configuration management, and cross-project reuse.
6 Interactive Tools
Experiment with visual tools that bring freedom from interference concepts to life.
FFI Partitioning Visualizer
Visualize temporal and spatial partitioning boundaries between ASIL components in an interactive system view.
MPU Configuration Tool
Configure memory protection unit regions for your MCU architecture and validate ASIL boundary isolation.
Multi-Core Interference Analyzer
Identify shared resource contention points between cores and model their impact on timing and interference.
AUTOSAR OS Configurator
Explore AUTOSAR OS partition and application configuration options for FFI compliance interactively.
Temporal Budget Calculator
Calculate and validate time partition budgets for mixed-ASIL tasks with deadline monitoring configuration.
FFI Evidence Checklist
Work through the required verification evidence for FFI partitioning with status tracking and gap identification.
FFI Partitioning for a Mixed-ASIL Body Control Module on a Dual-Core MCU
Design and verify Freedom from Interference for a Body Control Module hosting ASIL-B airbag functions alongside QM body comfort functions on a shared dual-core processor.
- Temporal partitioning: ASIL-B tasks in 1 ms protected window, QM tasks in 5 ms window with 10% budget margin
- MPU configured with 8 regions isolating ASIL-B RAM, stack, and peripheral access from QM software
- Multi-core: cache locking applied to ASIL-B code sections; L2 cache monitoring added for shared data regions
- AUTOSAR OS: separate OS-Applications with trusted/non-trusted split; MemProtectionHook configured
- Verification: 500-cycle fault injection test, 0 FFI violations detected across 1M test iterations
FFI Partition Map
Ready to Master Freedom from Interference?
Work through 12 detailed chapters with interactive partitioning tools and a complete dual-core BCM case study.
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