Non-intrusive trace
ETM generates trace packets in hardware, in parallel with core execution. No code instrumentation, no probe effect, no timing distortion.
Non-intrusive hardware trace acquisition for ARM-based SoCs
ChipTrace uses the ARM CoreSight on-chip debug infrastructure (ETMv4, ETF, CSTF, ETR, TPIU) to capture instruction-level execution traces at full CPU clock speed. The trace path is purely hardware: zero instrumentation, zero CPU overhead, cycle-accurate timestamps.
Ref: ARM IHI 0029E — CoreSight Architecture Specification v3.0
What ChipTrace does and how it works
ETM generates trace packets in hardware, in parallel with core execution. No code instrumentation, no probe effect, no timing distortion.
Trace data is output on the ATB (AMBA Trace Bus) at core clock speed. No sampling, no dropped packets when ETF buffering is correctly sized.
ChipTrace configures the on-chip CoreSight components directly via APB register access: ETM,STM, TMC (ETF,ETB,ETR), CSTF funnels, Replicator, Timestamp genererator. No proprietary hardware required.
ChipTrace integrates with Lauterbach TRACE32 via PRACTICE scripts for CoreSight path setup. Configuration follows the Lauterbach app note "Setup of the Debugger for a CoreSight System" (app_arm_coresight.pdf).
Where hardware trace is required or strongly beneficial
ASIL-D projects on S32G gateway SoCs require proof of deterministic execution paths. Hardware trace provides objective evidence of code coverage and worst-case execution time without altering the test conditions.
Certification authorities accept hardware trace as structural coverage evidence (MC/DC, statement, branch). The non-intrusive nature of ETM trace means test results are not invalidated by probe effects.
Measure actual context switch latency, ISR entry-to-exit time, and lock hold duration from the trace stream. Results are cycle-accurate and obtained on the production binary, not an instrumented build.
On heterogeneous SoCs (e.g. S32G2: A53 + M7), ChipTrace correlates traces from all cores using the shared TSG timestamp. Inter-core communication sequences (shared memory, mailbox interrupts) appear on a single unified timeline.
ChipTrace (ETM-based) compared to instrumentation-based trace tools
| Parameter | ChipTrace (HW) | SW instrumentation |
|---|---|---|
| CPU overhead | 0% (ETM in parallel) | 2-15% (probe effect) |
| Timing resolution | Cycle-accurate (TSG) | Microsecond (SysTick) |
| Instruction-level | Yes (every branch) | No (function-level) |
| Requires source code | No (stripped binaries) | Yes (build-time) |
| Race detection | Deterministic | Heuristic |
| RTOS awareness | Complementary | Native |
Network processor
4x A53 (1.6 GHz)
Full CoreSight topology
LS1043A RM, debug ch.
Validated
Applications processor
2-4x A35 (1.2 GHz) + M4F
CoreSight ETM, funnel, TPIU
i.MX 8QXP RM, debug ch.
Validated
High-performance MCU
M7 (480 MHz) + optional M4
ETM, ITM/DWT, SWO
RM0433, debug ch.
Validated
SoC FPGA (ZCU102/106)
4x A53 (1.5 GHz) + 2x R5F (600 MHz)
ETM, ETF, funnel, TPIU, FTM
Zynq US+ TRM UG1085
Validated