| Model | Memory | OS | TRACE32 Mode | Automotive Example |
|---|---|---|---|---|
| SMP (Symmetric) | Shared RAM + shared OS kernel | Single AUTOSAR OS instance manages all cores | Single session; all cores visible in TASK.List | QNX SMP on Renesas R-Car: ADAS domain controller |
| AMP (Asymmetric) | Private RAM per core + shared LMU | Separate OS per core (e.g., AUTOSAR on TC0, SafeRTOS on TC1) | Multi-session; each core has independent TRACE32 session | Aurix TC397: TC0=AUTOSAR, TC1=SafeOS, TC2=MCAL |
SMP vs AMP Multi-Core Models
Aurix TC3xx Core Configuration
CMMaurix_multicore_connect.cmm
// Connect to all 3 Aurix TC397 TriCore cores simultaneously
// TRACE32 ICD3 license required for 3-core debug
SYStem.RESet
SYStem.CPU TC397
// Define all 3 cores — each gets independent context
CORE.ASSIGN 1. 2. 3. // Core0=1, Core1=2, Core2=3
// Connect via single JTAG TAP (Aurix uses shared JTAG entry point)
SYStem.JtagClock 10MHz
SYStem.Option WATCHDOG OFF
SYStem.Up // powers up all 3 cores simultaneously
// Load ELF for each core (separate ELF per core in AMP; shared in SMP)
CORE.select 1.
Data.LOAD.Elf build/core0_autosar.elf /RELPATH
CORE.select 2.
Data.LOAD.Elf build/core1_safeos.elf /RELPATH
CORE.select 3.
Data.LOAD.Elf build/core2_mcal.elf /RELPATH
// Verify: each core should show different PC (different code areas)
CORE.select 1. ; PRINT "Core0 PC: " FORMAT.ADDRESS(Register(PC))
CORE.select 2. ; PRINT "Core1 PC: " FORMAT.ADDRESS(Register(PC))
CORE.select 3. ; PRINT "Core2 PC: " FORMAT.ADDRESS(Register(PC))Core Halting Strategies
| Strategy | TRACE32 Command | Use Case |
|---|---|---|
| Halt selected core only | Break (with CORE.select N active) | Inspect one core without disturbing others; inter-core shared data may change |
| Halt all cores simultaneously | Break.ALL | Consistent snapshot of all cores; required for cross-core race condition analysis |
| Halt on cross-core event | MCDS cross-core trigger | Core1 triggers halt of Core0 when Core1 hits a breakpoint |
| Non-stop: run other cores while one is halted | SYStem.Option HALTONRESET OFF | Core0 halted for step-debug while Core1/2 continue handling CAN/Ethernet |
Multi-Core TRACE32 Window Layout
CMMmulticore_layout.cmm
// Multi-core debug window layout: show all 3 cores simultaneously
// Core 0 — AUTOSAR tasks
CORE.select 1.
WinPOS 0. 0. 80. 15.
List.Mix // source for Core0
WinPOS 0. 16. 80. 8.
Frame.view /Locals // Core0 call stack
// Core 1 — SafeOS
CORE.select 2.
WinPOS 82. 0. 160. 15.
List.Mix // source for Core1
WinPOS 82. 16. 160. 8.
Frame.view /Locals // Core1 call stack
// Core 2 — MCAL
CORE.select 3.
WinPOS 0. 25. 160. 8.
Register /SpotLight // Core2 register view
// Shared LMU RAM — visible from all cores
WinPOS 0. 34. 160. 8.
Data.dump 0x70000000 // LMU shared variables
// Cross-core message queue (circular buffer in LMU)
WinPOS 0. 43. 160. 8.
Var.Watch %Open g_crossCoreQueue // IPC queue stateSummary
AMP is the dominant model in safety-critical automotive SoCs: separate RTOS instances on each core with well-defined IPC boundaries isolate safety partitions. TRACE32 handles AMP by assigning independent debug contexts per core (CORE.select N) while maintaining a single physical JTAG connection. Break.ALL halts all cores simultaneously — essential for capturing consistent cross-core state. The non-stop mode (keep other cores running while one is halted) is critical for real-time systems where CAN communication must not be interrupted by a single-core debug session.
🔬 Deep Dive — Core Concepts Expanded
This section builds on the foundational concepts covered above with additional technical depth, edge cases, and configuration nuances that separate competent engineers from experts. When working on production ECU projects, the details covered here are the ones most commonly responsible for integration delays and late-phase defects.
Key principles to reinforce:
- Configuration over coding: In AUTOSAR and automotive middleware environments, correctness is largely determined by ARXML configuration, not application code. A correctly implemented algorithm can produce wrong results due to a single misconfigured parameter.
- Traceability as a first-class concern: Every configuration decision should be traceable to a requirement, safety goal, or architecture decision. Undocumented configuration choices are a common source of regression defects when ECUs are updated.
- Cross-module dependencies: In tightly integrated automotive software stacks, changing one module's configuration often requires corresponding updates in dependent modules. Always perform a dependency impact analysis before submitting configuration changes.
🏭 How This Topic Appears in Production Projects
- Project integration phase: The concepts covered in this lesson are most commonly encountered during ECU integration testing — when multiple software components from different teams are combined for the first time. Issues that were invisible in unit tests frequently surface at this stage.
- Supplier/OEM interface: This is a topic that frequently appears in technical discussions between Tier-1 ECU suppliers and OEM system integrators. Engineers who can speak fluently about these details earn credibility and are often brought into critical design review meetings.
- Automotive tool ecosystem: Vector CANoe/CANalyzer, dSPACE tools, and ETAS INCA are the standard tools used to validate and measure the correct behaviour of the systems described in this lesson. Familiarity with these tools alongside the conceptual knowledge dramatically accelerates debugging in real projects.
⚠️ Common Mistakes and How to Avoid Them
- Assuming default configuration is correct: Automotive software tools ship with default configurations that are designed to compile and link, not to meet project-specific requirements. Every configuration parameter needs to be consciously set. 'It compiled' is not the same as 'it is correctly configured'.
- Skipping documentation of configuration rationale: In a 3-year ECU project with team turnover, undocumented configuration choices become tribal knowledge that disappears when engineers leave. Document why a parameter is set to a specific value, not just what it is set to.
- Testing only the happy path: Automotive ECUs must behave correctly under fault conditions, voltage variations, and communication errors. Always test the error handling paths as rigorously as the nominal operation. Many production escapes originate in untested error branches.
- Version mismatches between teams: In a multi-team project, the BSW team, SWC team, and system integration team may use different versions of the same ARXML file. Version management of all ARXML files in a shared repository is mandatory, not optional.
📊 Industry Note
Engineers who master both the theoretical concepts and the practical toolchain skills covered in this course are among the most sought-after professionals in the automotive software industry. The combination of AUTOSAR standards knowledge, safety engineering understanding, and hands-on configuration experience commands premium salaries at OEMs and Tier-1 suppliers globally.