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The Universal Debug Probe

J-Link PRO is a refined version of the regular J-Link. It has an Ethernet interface in addition to the USB interface, as well as two additional LEDs which are used as hardware status indicators. It connects via Ethernet or USB to the host, running Windows, Linux or macOS.

  • Additional Ethernet interface
  • Download speed up to 3 MByte/s
  • Superset of J-Link ULTRA+



About J-Link PRO

J-Link PRO is fully compatible with J-Link and can be used "out-of-the-box". J-Link PRO uses DHCP per default. The built-in webserver makes manual configuration easy. Ethernet allows using the debug probe far away from the PC, over a hardwired or wireless network, in a development or production environment; download and debugging speed is higher and Ethernet provides electrical isolation from the PC. All features of the regular J-Link also apply to this product.

Why Use J-Link PRO?



Up to 3 MByte/s download speed make J-Link PRO the fastest debug probe on the market. Using TCP/IP instead of USB eliminates latencies from USB usage, resulting in higher debugging speed.

SEGGER Flexibility Icon


Due to the Ethernet interface, long distances between the development PC and the target system are possible. You can set a default gateway for J-Link PRO, so it is also possible to use it in large intranets.

SEGGER Electronic Isolation Icon

Safety (Galvanic isolation)

Ethernet signal lines provide galvanic isolation of J-Link PRO (and so the target system) from the network and development PC.

SEGGER Flash Breakpoints Icon

Flash Breakpoints

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 – J-Link Debugger

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-Flash is a PC software to program internal and external flash memory of a microcontroller-based embedded system via J-Link or Flasher.

Further Advantages

  • Comes with web interface for easy TCP/IP configuration (built-in webserver)
  • 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
  • Free software updates
  • Additional LEDs for power and RESET indication

J-Link PRO Licensing

J-Link PRO 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 PRO 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.


SEGGER J-Link Flash Breakpoint Introduction


SEGGER J-Flash Introduction

J-Link PRO Specifications

Supported OSMicrosoft Windows 2000, XP, 2003, Vista, 7 and newer (32 bit and 64 bit versions)
macOS 10.5 and higher
Electromagnetic compatibility (EMC)EN 55022, EN 55024
Operating temperature+5°C ... +60°C
Storage temperature-20°C ... +65 °C
Relative humidity (non-condensing)Max. 90% rH
Size (without cables)100mm x 53mm x 27mm
Weight (without cables)73g
Available Interfaces
Ethernet interface100 Mbit/s
USB interfaceUSB 2.0 (Hi-Speed)
Target interfaceJTAG/SWD 20-pin
JTAG/SWD Interface, Electrical
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 voltageVOL <= 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. 50 MHz
SWO sampling frequencyMax. 100 MHz
Data input rise time (Trdi)Trdi <= 20ns
Data input fall time (Tfdi)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
Analog power measurement interface
Sampling frequency200 kHz
Resolution50 uA

Package Content

J-Link PRO Debug Probe with Ethernet

J-Link PRO


Ethernet cable


 .1" 20-pin ribbon cable


USB cable