Segger System View - Real time recording for embedded system behavior - Sightsys SEGGER SystemView Real-Time Analysis

SEGGER SystemView — Real-Time Recording for Embedded System Behavior

SEGGER SystemView is a real-time recording and visualization tool for embedded systems. Unlike traditional debuggers, it reveals the true runtime behavior of your application. As a result, developers gain unprecedented visibility into how their code actually behaves on the target hardware. Sightsys officially distributes SEGGER SystemView in Israel. We provide local sales, technical support, and training to embedded development teams across the country.

Why Choose SEGGER SystemView

Complex embedded systems contain multiple threads and interrupts. In those environments, traditional debugging falls short. However, SEGGER SystemView gives you a complete real-time view of every task, ISR, and event on your device. Therefore, the system can be verified against the design. In addition, inefficiencies surface quickly. Finally, unintended interactions and resource conflicts become visible.

For example, when an RTOS task misses its deadline, SystemView shows exactly which interrupt or higher-priority task delayed it. Similarly, when CPU usage spikes unexpectedly, the responsible code path becomes obvious. As a result, debugging becomes faster, more predictable, and far less frustrating.

Key Features of SEGGER SystemView

Real-time recording with minimal CPU and memory overhead
Detailed visualization of tasks, interrupts, and scheduler events
Full RTOS support — embOS, FreeRTOS, uC/OS-III, Micrium OS Kernel, NuttX, Zephyr
Continuous live recording over J-Link for unlimited capture
Intuitive timeline and context views that simplify root-cause analysis
Bare-metal support — works without an RTOS too
Free for non-commercial use — every developer can try the tool today

Watch SEGGER SystemView in Action

The demonstration below walks through a live SystemView session. You’ll see tasks, interrupts, scheduler events, and heap monitoring — all visualized in real time:

Documentation and Free Download

To get started with SEGGER SystemView, first explore the official SEGGER resources below:

Full Feature List

Continuous real-time recording of an embedded system
Captures tasks, interrupts, timers, resources, API calls, and user events
Recording via J-Link + SEGGER RTT Technology, IP, or UART
Live analysis and visualization of captured data
Minimally system-intrusive
Works on any CPU
Works with any RTOS and with bare-metal systems
SEGGER embOS, emNet, and emFile API call tracing as standard
uC/OS-III, Micrium OS Kernel, FreeRTOS, NuttX, and Zephyr instrumentation included
Free for non-commercial use without limitation

Online Documentation

Supported RTOS

Several major RTOS kernels work with SystemView out of the box. These include embOS, uC/OS-III, Micrium OS Kernel, FreeRTOS, NuttX, and Zephyr. For the full list and integration notes, see more about supported RTOS.

Recording Events

What SystemView Captures

On the target system, SystemView records every runtime event. Such events include interrupts and timers. They also cover task switches and scheduling under an RTOS. In addition, API function calls and returns get captured. Finally, user events and messages are recorded too. Meanwhile, the target keeps running normally — SystemView analyzes everything live.

To keep target overhead low, only basic information gets recorded. Afterwards, the host application reconstructs the rest.

What SystemView Shows You

SystemView analyzes the raw events and presents:

The API function name with its parameters and values
The recording time or system time when the call happened
The task in which the call happened
The duration of the API call

Sample output: “API function with Id x has been called with parameter values y and z, n ticks after the last event.”

Overhead and Timing Accuracy

A regular event is 4 to 8 bytes long. Moreover, it takes about 1 µs to record at 200 MHz. At 10,000 events per second, SystemView adds less than 1% CPU overhead. Meanwhile, the recorded data fits well within the bandwidth limits of the recorder. As for timing — event timestamps are accurate to a single CPU cycle. That equates to 5 ns on a 200 MHz CPU.

Event Timeline Window

Most embedded systems do not execute linearly. Instead, they implement interrupts for timers and peripherals. Many also use an RTOS with multiple tasks. As a result, the target generates events on every interrupt enter and leave. It also generates events when each task becomes ready, starts, or stops.

The SystemView application plots these events in the Timeline Window. Furthermore, it shows the full context in which each event happens. Therefore, engineers can analyze when, how long, and why tasks run. They can also see what happens on each interrupt.

Issues the Timeline Reveals

Incorrect task priorities or priority inversion leading to starvation
Incorrect inter-task communication
Inefficient delays and timeouts
Questionable or unnecessary interrupts

Context Statistics Window

SystemView helps users identify blocking reasons. Specifically, the Context Statistics Window shows total active time, blocked time, and suspended time for each task. Blocked time is also categorized into segments. Such segments include blocks caused by interrupts, blocks caused by other tasks, and blocks caused by the scheduler. Furthermore, the view names the specific task or interrupt responsible for each block.

Users select any task to analyze through a drop-down menu. Additionally, the “Hide when empty” checkbox keeps the overview clean. As a result, only the events that actually occurred remain visible.

Optimizing Task Performance

CPU cycles are limited on embedded systems. Therefore, engineers must optimize task performance, get execution order right, and time the distribution correctly.

The CPU Load Window helps analyze where load runs high. By knowing what happens at or before each peak, engineers can tune the system. Consequently, bottlenecks get avoided. Important tasks no longer suffer delayed execution.

Additionally, the Runtime Window provides information about runtime distribution across contexts. Use it to verify each context runs within its timing limits. Alternatively, use it to find cases where a context unexpectedly runs too long.

Tracking and Measuring Performance

SystemView includes purpose-built events that mark key points in the target system. For example, to measure the duration from point A to point B, simply generate marker-start and marker-stop events. Similarly, to measure A through B to C, add a marker in between. Afterwards, the SystemView application automatically links the markers. Furthermore, it adds run time and run count for every measurement.

Logging Output

SystemView logs messages alongside the recording. Simple strings can be recorded as a log, warning, or error message. Moreover, the logging functions support printf-style formatting. However, formatting strings can be time-consuming and memory-heavy on the target. Therefore, SystemView defers that work to the host. The target simply records the format string and the parameters in one event. Afterwards, the SystemView application formats and prints the result in the Terminal Window.

Heap Monitoring

SystemView monitors heap memory allocation. In many cases, memory can be allocated for the lifetime of the application without a problem. However, when the peak heap load keeps growing over time, the application is leaking memory. Eventually, it will run into trouble.

Fortunately, SystemView’s heap monitoring makes it easy to see where every allocation happens. As a result, engineers get strong clues about where the leak originates. For more detail, see heap monitoring documentation.

please refer to heap monitoring from sightsys Blog

Get SEGGER SystemView in Israel

Sightsys is the official SEGGER distributor in Israel. Specifically, we provide local sales, technical support, training, and integration help. Our coverage includes the full SEGGER line. Tools we support include SystemView, J-Link, embOS, emFile, and emNet. Need help getting SystemView running on your STM32, NXP, or Renesas target? Our team has hands-on experience with the integration challenges Israeli embedded teams face.

New to runtime tracing? Read our companion article — Embedded Dynamic Memory Management: Heap, Risks & Tools. It covers the SystemView V4 ELF integration and a heap monitoring deep-dive. Ready for pricing or a demo? Contact the Sightsys team directly.