J-Link WiFi

J-Link WiFi is the wireless option, when the targeted embedded device is moving or has to be shielded from the environment. It is USB powered, so that it can use the same power source as the target device. It can communicate at high speed with the supported target CPUs.

The J-Link debug probes are supported by all major IDEs including Eclipse, GDB-based IDEs and SEGGER Embedded Studio. For a complete list, please refer to Supported IDEs. J-Link is probably the most popular debug probe for ARM and RISC-V cores, making it the de-facto standard.

Key features

  • Provides J-Link debugging for mobile applications
  • Built-in VCOM functionality
  • Comes with integrated licenses for: Unlimited breakpoints in flash memory (Unlimited Flash Breakpoints), RDI / RDDI and J-Flash
  • Supports a broad range of microcontrollers
  • Multiple CPUs supported—8051, PIC32, RX, ARM7/9/11, Cortex-M/R/A, RISC-V [More..]
  • Supports direct download into RAM and flash memory

Why Use J-Link WiFi?

J-Link Wifi Mobility
J-Link Wifi Safety
J-Link Wifi Flash Breakpoints
J-Link Wifi Ozone



Flash Breakpoints

Ozone – J-Link Debugger

Due to the WLAN/WiFi interface, the debug interface can also be used, if there is movement between the development PC and the target system. This is particularly useful in robotic applications.

In specific use cases, where the target system operates inside a hazardous environment, the wireless connection enables the developer to stay outside the dangerous area with his development system, even if there is a physical barrier between development and target system.

The J-Link software comes with an additional feature, called Unlimited Flash Breakpoints. Unlimited Flash Breakpoints allow the user to set an unlimited number of breakpoints when debugging in flash memory.

Ozone is the debugger for J-Link and J-Trace. It includes all well-known debug controls and information windows and makes use of the best performance of J-Link and J-Trace debug probes.

J-Link Wifi Use Case

J-Link WiFi Licensing

J-Link WiFi comes with licenses for all J-Link related SEGGER software products: J-Link Unlimited Flash Breakpoints, J-Link RDI / RDDI, J-Flash, J-Link GDB Server, providing the optimum debugging solution for professional developers.

J-Link WiFi can be used with almost all ARM debuggers, enabling download to flash memory with an unlimited number of breakpoints when debugging programs located in flash memory of most popular ARM microcontrollers. It also comes with the license to use J-Flash, SEGGER’s popular flash programming software.


Supported OSMicrosoft Windows (x86 / x64 / Arm64),
Linux (x86 / x64 / Arm / Arm64),
macOS (x64 / Apple Silicon)
Electromagnetic compatibility (EMC)EN 301 489-1/-17, EN 300 328, EN 62368
Operating temperature+5°C … +60°C
Storage temperature-20°C … +65 °C
Relative humidity (non-condensing)Max. 90% rH
Size (without cables)103mm x 53mm x 28mm
Weight (without cables)70g
Available Interfaces
WiFi interfaceIEEE 802.11 b/g/n (2.4 GHz)
USB interfaceUSB 2.0 (Hi-Speed)
Target interfaceJTAG / SWD 20-pin
JTAG/SWD Interface, Electrical
Power supplyUSB powered, max. 220mA@5V
Target interface voltage (VIF)1.2V … 5V
Current drawn from target voltage sense pin (VTRef)< 25µA
Target supply voltage5V (derived from USB voltage)
Target supply currentMax. 300mA
Reset typeOpen drain. Can be pulled low or tristated
Reset low level output voltage (VOL)VOL <= 10% of VIF
For the whole target voltage range (1.2V <= VIF <= 5V)
LOW level input voltage (VIL)VIL <= 40% of VIF
HIGH level input voltage (VIH)VIH >= 60% of VIF
For 1.2V >= VIF <= 3.6V
LOW level output voltage (VOL) with a load of 10 kOhmVOL <= 20% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhmVOH >= 80% of VIF
For 3.6 <= VIF <= 5V
LOW level output voltage (VOL) with a load of 10 kOhmVOL <= 20% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhmVOH >= 80% of VIF
JTAG/SWD Interface, Timing
Target interface speedMax. 15 MHz
SWO sampling frequencyMax. 30 MHz
Data input rise time (Trdi)Tfdi <= 20ns
Data output rise time (Trdo)Trdo <= 10ns
Data output fall time (Tfdo)Tfdo <= 10ns
Clock rise time (Trc)Trc <= 3ns
Clock fall time (Tfc)Trc <= 3ns

Package content

J-Link WiFi
USB Cable
20Pin Target Ribbon

J-Link WiFi

USB cable

20-pin, 0.1″ target ribbon cable