Segger J-Link EDU Programmer-Debugger

The Segger J-Link line includes many options, with prices ranging from USD60 to almost USD1800, not to mention the production programmers.

​Luckily, Segger offers the J-Link EDU at USD60 for educational and non-commercial purposes. 

I tested the Segger J-Link Edu version successfully on the Arduino Due,  the Adafruit Feather M0, the Adafruit Feather nRF52, the LaunchPad MSP432. 
​

However, I had to solve two challenges.

• First, I needed an adapter and bought the JTAG (2x10 2.54mm) to SWD (2x5 1.27mm) Cable Adapter Board and a 10-pin 2x5 Socket-Socket 1.27mm IDC (SWD) Cable - 150mm long, both from Adafruit. 
• Second, I had to place the connector on the right position onto the board or build my own connector to use the Segger J-Link.

Connecting to Boards 

Two connections are available:

• JTAG with 4 signals, TCK, TMS, TDI and TDO
• SWD with 2 signals, CLK and DIO, and optional serial port

GND is connected to the ground of the target. VTref is connected to the VCC of the target to set the logic level.

​Optionally, the programmer-debugger can power the target, albeit in +5V only.

I've tested the Segger J-Link with the following boards:

• Adafruit Feather M0 and Adafruit Feather M4
• Adafruit Feather nRF52
• Arduino Due
• ​Arduino Primo Core
• LaunchPad MSP432

​Really nice to have the same tools for all the boards!

Software

Segger provides the basic J-Link Tools Suite, and more elaborate applications like Ozone, a graphical debugger.

Most of the utilities support Windows, macOS and Linux.

​Go to the review of the Segger J-Link Software.

Additional features

Additionally, the Segger J-Link Edu debug probe can power the board directly and re-route a serial console.

• The Segger J-Link Edu debug probe can power the board with +5 V (300mA maximum, pin 19), while the logic level is set through VTref (target reference voltage, pin 1).

• The Segger J-Link Edu debug probe features VCOM and re-routes a serial console through J-Link TX (pin 5) and J-Link RX (pin 17).

This feature is disabled by default and is only valid with SWD.

To enable it, launch JLinkConfig and set Virtual COM-Port to Enable. Power-cycle the probe. 

If the probe has the serial number 123456789, the serial port is re-routed to /dev/tty.usbmodem000123456789.​

More information is available at the Interface Description and  J-Link Debug Probes pages.

Example of SWD configuration
with re-routed serial port (Vcom)

​Conclusion

​I'm very happy with this Segger J-Link programmer-debugger. It is fast, comes with reliable software and well-written documentation. The Ozone application offers a decent graphical interface for debugging.

​Support is very responsive and provided through the Segger forum.

I've added support for debugging against the Adafruit Feather M0, Adafruit Feather nRF52, Arduino Due, Arduino Primo Core boards with the Segger J-Link.

A new product offers the same features for less than USD20: see the Segger J-Link EDU mini Programmer-Debugger.

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Pros

• One debugger for almost all Cortex-M and Cortex-A MCUs
• Software suite
• Extensive documentation

Cons

• Some issues with OpenOCD
• Some boards lacks fool-proof SWD connector

Wrap-Up

• Specific offer for educational and non-commercial usage
• Reliable software and extensive documentation  
• Great value

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Links

• Segger website
• Product page​
• Segger forum
• Supported MCUs

​Posted: 22 Aug 2016
Updated: 08 Sept 2017, 20 Jan 2020, 31 Jan 2020, 25 Apr 2022