J-Trace PRO Cortex-M

The J-Trace PRO Cortex-M is the most accessible J-Trace model, delivering full trace capability for Arm Cortex-M0 through M85 microcontrollers at a competitive price. Where standard debug probes can only halt execution and inspect state at breakpoints, J-Trace captures a continuous, cycle-accurate record of every instruction executed on the target, providing a complete picture of runtime behavior that is impossible to achieve with breakpoint debugging alone.

ETM trace provides cycle-accurate, non-intrusive instruction trace that records the exact execution path of the firmware without affecting timing or behavior. This makes J-Trace indispensable for diagnosing race conditions, timing-dependent bugs, and hard faults that disappear when breakpoints are inserted. Hardware-based code coverage supports MC/DC, branch, and statement metrics for safety certification under IEC 61508, ISO 26262, and DO-178C.

Continuous trace streaming over USB 3.0 SuperSpeed handles long-running trace capture sessions without the buffer depth limitations of on-probe storage, while execution profiling identifies performance hotspots and helps optimize timing-critical firmware loops.

Trace Capabilities

Capability	Description
ETM Trace	Cycle-accurate instruction trace, full execution history
MTB (Micro Trace Buffer)	Lightweight trace on Cortex-M0/M0+ with limited trace pins
ITM (Instrumentation Trace)	Software-instrumented event and printf trace
SWO	Serial Wire Output for low-bandwidth trace data
DWT (Data Watchpoint & Trace)	Data access trace, cycle counter, exception trace
Code Coverage	MC/DC, branch, statement, IEC 61508, ISO 26262, DO-178C
Execution Profiling	Function-level timing, hotspot identification
Data Trace	Monitor variable changes in real-time without halting
Trace Streaming	Continuous capture over USB 3.0, no buffer depth limit
Trace Triggering	Start/stop trace on address, data value, or event

Full J-Link Feature Set

All J-Link features are included alongside the trace capabilities:

Feature	Specification
Download Speed	Up to 4 MB/s
Host Interface	USB 3.0 SuperSpeed
Debug Interface	JTAG, SWD, cJTAG
Architectures	Arm Cortex-M0 through M85
Flash Breakpoints	Unlimited
RTT	Real-time terminal, bidirectional
GDB Server	Full IDE compatibility
IDE Compatibility	Embedded Studio, Keil MDK, IAR EWARM, Eclipse, VS Code

Watch the SEGGER J-Trace PRO Cortex-M introduction

The combination of full trace and standard debug in one probe means teams do not need separate devices for debug and trace workflows, the J-Trace PRO Cortex-M covers both from a single USB connection.