Your "One-Stop-Shop" for your next Embedded Project

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embOS-Trace offers detailed and comprehensive insight into the runtime world for embedded software developers using embOS and SEGGER's leading debug probe J-Link. It improves the understanding of the behavior of a software and the changes made to it during the development process, thereby increasing development speed and efficiency notably.

Comprehensive insight into runtime behavior

embOS-Trace visualizes the runtime behavior of embedded software through more than 20 graphical views of runtime events, such as scheduling, interrupt handlers, kernel calls and application events. It thereby complements the code-level debugger perspective with the overall picture. The views are interconnected and intuitive to use.

embOS-Trace takes advantage of the high performance of the J-Link debug probes to offer continuous trace streaming of runtime events, such as scheduling, interrupt handlers, kernel calls and application events.

It uses software-defined trace, where events are stored in a RAM buffer. This modus is very flexible, easy-to-use, and does not depend on hardware trace support. The events are written to a target-side RAM buffer (typically 512 Byte - 1KB), and then extracted by J-Link via live memory reads, without interfering with the executing system. The transfer is very fast and robust.

Moreover, in embOS-Trace the trace length is no longer limited by the available RAM. Continuous trace streaming over unlimited duration is now possible, requiring just a standard J-Link debug probe and a small RAM buffer.

Using embOS with embOS-Trace

embOS-Trace is designed for use with SEGGER J-Link debug probes and allows for continuous trace streaming on any J-Link, for essentially unlimited durations. All that is needed is a SEGGER J-Link / J- Trace debug probe, a version of SEGGER embOS (version 4.06b or later) and the Percepio trace recorder library, included in the Percepio embOS-Trace installation.

For a start, an embOS Cortex-M or RX trial version from and the Percepio embOS-Trace tool from are required.

If you are using the project which comes with this application note, you can start right away and download and build the project. For further instructions on how to use embOS with embOS-Trace, please refer to the Application Note.

Application Notes and sample projects

  Manual   Sample project
CPU / Board
AN01003_Percepio_embOSTrace_DemoProject.pdf Percepio TraceDemo for STM3240G-Eval ST STM32F4 /
ST STM3240G-Eval

Using Percepio Tracealyzer with an existing project 

Examples of graphical views

Tasks, System Calls and User Events

The main trace view shows all recorded events visualized on a vertical time-line, including task execution timing, interrupts, system calls and custom user events. The task and interrupt trace are shown as colored rectangles. Events are shown as floating text labels. Zooming is very easy using a click-and-drag selection, which also works as a measurement tool. Tasks and events can be clicked and highlighted for additional information, including timing and event dependencies.

CPU Load

This view presents a horizontal time-line showing the total CPU usage, and also CPU usage per task/interrupt. The CPU Load Graph allows for navigating the main trace view, since a double click in the CPU Load Graph focuses the main trace view on the clicked interval. Zooming is allowed in this view as well, independently of other views, and filters are available for focusing on individual tasks or interrupts.

The embOS-Trace tool is part of the Tracealyzer product family developed by Percepio, the Swedish supplier of RTOS visualization tools. More information and the download can be found here: