J-Scope adds data visualisation to J-Link debugger

July 30, 2014 // By Graham Prophet
Segger’s J-Scope is a data visualisation software tool for the J-Link family of debug probes. J-Scope is an application to analyse and visualise data on a microcontroller in real-time, while the target is running.

It provides a real-time, accurate representation of the sampled variables enabling the engineer to better understand the embedded application. J-Scope is based on the recently introduced J-Link HSS (High Speed Sampling) feature, which makes it possible to continuously sample variables at extremely high speeds without affecting the real-time nature of the embedded device. Using the standard debug interface, it does not require any extra resources on the target such as memory, CPU time or extra pins. The periodic sampling is done autonomously by the J-Link. This allows considerably higher sampling rates and more precise timing than other debug probes. J- Scope uses this feature to read the target variable data and display both the value and an oscilloscope-like trace.

Examples of where HSS and J-Scope can be used is in monitoring network stack loads, or monitoring a 3-phase 50 Hz signal on a motor control application.

“The release of J-Scope makes it possible to display and analyse real-time behaviour in a unique way, which has been a user request. Previously, those who needed to monitor variables have had to rework their application and attempt to use other communication interfaces to transmit this data, with varying success. Having HSS available through the debug probe and also open through the J-Link SDK makes monitoring variables a lot easier,” comments Alexander Gruener, Segger J-Link Product Manager.

J-Scope supports all CPUs with some form of background memory read, including most Cortex-M CPUs, and Renesas RX. J-Scope is available free of charge as a part of the J-Link Software and Documentation Pack version 4.90a and later, and can be downloaded at http://Segger.com/jlink-software.html

The Segger J-Link is tool-chain-independent and works with free GDB-based tool chains such as emIDE and Eclipse, as well as commercial IDEs from: Atmel, Atollic, Coocox, Cosmic, Freescale, IAR, KEIL, Mentor Graphics, Microchip, Python, Rowley, Renesas, Tasking and others. J-Link supports multiple CPU families, such as ARM 7, 9, 11, Cortex-M, Cortex-R, Cortex-A