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  • J-Link debug probes
  • J-Link BASE

    J-Link BASE
    The entry-level debug probe

    Buy now
    Compare J-Links
    Documentation
    SEGGER J-Link BASE + BASE Compact debug probe
    1. 1.Key features
      1. 1.1.High download speeds
      2. 1.2.Real Time Transfer
      3. 1.3.Broad CPU and IDE support
    2. 2.Use cases
      1. 2.1.Entry-level debug hero
      2. 2.2.Basic debug support
    3. 3.Upgrade path
    4. 4.Software
    5. 5.Supported devices
    6. 6.Customer support
    7. 7.Product photos
    8. 8.Technical specifications
      1. 8.1.Assembly dimensions
    9. 9.FAQ

    Overview

    The J-Link Base is the perfect level for the average developer to jump into the wide world of J-Link. It offers a respectable download speed of 1 MB/s.

    All J-Links feature high-speed programming (from 1 MB/s up to 4 MB/s), built-in VCOM functionality, and support for a broad range of microcontrollers. Plus all future software and firmware updates, as well as any new flash loaders for target devices that will be added, are free of charge. And all J-Link debug probes are supported by all major IDEs including Eclipse, GDB-based IDEs and SEGGER Embedded Studio.

    For speeds of up to 4 MB/s, and for features such as unlimited breakpoints in flash memory, use with Ozone, RDI/RDDI and J-Flash, web interface for easy configuration (built-in webserver), there are many other options in the J-Link family of debug and trace probes.

    J-Link BASE is available in two form factors with identical functionality: J-Link BASE Classic and J-Link BASE Compact.

    Key features

    A gray circular button featuring a downward arrow above a horizontal line, indicating a download action.

    High download speeds

    J-Link BASE offers download speeds of up to 1 MB/s, ensuring that project development moves forward smoothly and reliably, with minimized download times.

    A circular icon with a gray background and the letters "RTT" in the center. Two horizontal arrows point left and right on either side of the text, indicating a communication or connectivity function.

    Real Time Transfer

    J-Link BASE offers Real Time Transfer (RTT), which provides a simplified path for information to travel when an application is running. Users can also easily monitor changes in operation.

    Icon featuring three rectangular elements, each labeled with the letters X, Y, and Z stacked vertically. The background is circular and gray, contrasting with the white elements. The design suggests a structured arrangement, possibly related to categorization or labeling.

    Broad CPU and IDE support

    J-Link BASE works with an extensive range of microcontrollers and IDEs. It enables users to connect their selected microcontroller with their favorite IDE.


    Use cases

    A hand is seen connecting a wire to a circuit board with a small display screen. The setup is likely related to electronics or programming, with components arranged on a table. In the background, a computer monitor is partially visible.

    Entry-level debug hero

    J-Link BASE is a modern debug probe that is both smart and a swift communicator, which means communications are carried out not only reliably, but also faster than with a simpler probe. SEGGER's RTT debug communication interface is also available, and all popular IDEs offer support for J-Link.

    A black SEGGER J-Link Base debugging tool is prominently featured, connected by a USB cable. It has indicator lights and is positioned on a clear stand, with a flat ribbon cable connected to it. A blurred computer monitor is visible in the background.

    Basic debug support

    Should a toolchain not support the comprehensive feature set, including unlimited breakpoints in flash memory and monitor-mode debugging, found in the more-advanced J-Link products, J-Link BASE is a sensible, cost-efficient alternative for use with OpenOCD or similar tools.


    Upgrade path

    J-Link BASE offers basic functionality. To use the full range of features found in a J-Link PLUS, for example, the J-Link BASE to PLUS upgrade is required.

    This upgraded license includes a software bundle with a J-Flash/J-Flash SPI software license to program EEPROM and flash chips in microcontroller systems, and a J-Link Unlimited Flash Breakpoints license. Also included is the Ozone J-Link debugger and performance analyzer, monitor-mode debugging technology, and a license pack for the RDI/RDDI interface.

    J-Link's BASE to PLUS upgrade is available at shop.segger.com.

    An image of a software interface featuring multiple coding windows, showcasing programming and debugging activities. The central focus is a black icon labeled "Ozone" with binary code beneath a magnifying glass, symbolizing analysis or inspection of data.

    Ozone

    Ozone is a professional, full-featured standalone graphical debugger for embedded applications that is capable of debugging the output of any toolchain or IDE. It includes all common debug controls and information windows. Furthermore, it enables high-speed application-to-target programming and debugging of information windows for any purporse, including disassembly, memory issues, and more. Ozone is available with J-Link PLUS, PRO, PRO PoE, and ULTRA+.

    Read more
    The image displays a software interface for J-Flash, showing project settings and programming progress. Key details include project name, connection type, memory settings, and a progress bar indicating the programming status. The background consists of a circuit design pattern.

    J-Flash

    J-Flash enables programming of microcontroller internal and external flash memories. Exceedingly versatile, it runs on Microsoft Windows, Linux, and macOS, and it supports Cortex Arm, RX, and Power PC devices and cores. For all members of the J-Link and J-Trace families positioned above J-Link BASE, J-Flash is included in the J-Link Software and Documentation Package. 

    Read more
    An image of a software interface displaying programming code and debugging tools, overlaid with a graphic stating "Unlimited Breakpoints." The background features a circuit board design. The focus is on the software capabilities for debugging.

    Unlimited breakpoints

    Unlimited Flash Breakpoints is a special feature that is included with J-Link's software. It allows a user to set an unlimited number of breakpoints when debugging in flash memory. Without this feature, the number of breakpoints that can be set in flash memory is limited to the number of hardware breakpoints that the CPU's debug unit supports. For all members of the J-Link and J-Trace families positioned above J-Link BASE, Unlimited Flash Breakpoints is included in the J-Link Software and Documentation Package. 

    Read more

    Software

    All software is included free of charge. As a multi-platform solution, J-Link BASE comes with setup and control software for Linux, macOS, and Windows. Software and firmware updates are included. The J-Link Software and Documentation Package is available here:

    DownloadJ-Link Software and Documentation Pack

    Supported devices

    The list of supported manufacturers, families, devices, and systems on a chip includes tens of thousands of devices in hundreds of device families.

    Device not listed? Please don’t hesitate to contact us.

    Customer support

    J-Link Pro comes with one year (12 months) of Basic Support. Beyond that, SEGGER's Extended Coverage gives users the option to extend the hardware warranty and Basic Support for one additional year (12 months) or two additional years (24 months). These options are only available at the time of purchase, either through the Web Shop or upon request; adding coverage at a later date is not possible.
     

     Contact us      Detailed pricing information


    Product photos

    SEGGER J-Link BASE Classic host connector
    J-Link BASE Classic host connector
    SEGGER J-Link BASE debug probe
    J-Link BASE Classic front
    SEGGER J-Link BASE Compact debug probe
    J-Link BASE Compact front
    SEGGER J-Link Compact debug probe host connector
    J-Link BASE Compact host connector
    SEGGER J-Link BASE Classic target connector
    J-Link BASE Classic target connector
    SEGGER J-Link BASE Compact target connector
    J-Link BASE Compact target connector

      Technical specifications

      General
      Supported OSMicrosoft Windows (x86/x64), Linux (x86/x64/Arm), macOS (x86/Apple Silicon)
      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
      Mechanical
      Size of J-Link BASE Classic (without cables)100mm x 53mm x 27mm
      Weight of J-Link BASE Classic (without cables)70g
      Size of J-Link BASE Compact (without cables)46mm x 46mm x 17mm
      Weight of J-Link BASE Compact (without cables)20g
      Available Interfaces
      USB interface (J-Link BASE Classic)USB 2.0 (Hi-Speed); USB Type B
      USB interface (J-Link BASE Compact)USB 2.0 (Hi-Speed); USB-C
      Target interfaceJTAG/SWD 20-pin
      JTAG/SWD Interface, Electrical
      Power supplyUSB powered
      Max. 50mA + Target Supply current.
      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 with 100 Ohms series resistor. 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 <= 10% of VIF
      HIGH level output voltage (VOH) with a load of 10 kOhmVOH >= 90% 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)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

      Assembly dimensions

      The compact variant of the J-Link BASE is designed to mount securely and unobtrusively into development or end-user equipment. The housing's small size and two mounting holes enable the device to be placed into existing equipment housing or to conserve space for direct mounting to a printed circuit board.

      Typical applications for J-Link BASE include test fixtures that are used to automate firmware verification during development, as well as long-term testing setups. It can also be used for integrated firmware reflashing or for service purposes in end equipment, minimizing the number of tools required by service technicians.

      An exploded view of an electronic device, showing a black casing that houses a green circuit board with components and a connector. The circuit board features multiple small components, while golden pins are visible on one side of the assembly.

      Download PCB 3D-STEP data

      Technical diagram of a printed circuit board (PCB) illustrating its dimensions and layout. Key measurements include a width of 35.8 mm and height of 33.8 mm, with additional details such as hole diameters and component placements.

      Download PCB dimensions

      FAQ

      Q: Can I use J-Flash with J-Link BASE?

      A:  No. You either need the additional license J-Link Upgrade BASE to PLUS in case you already own the product. Another option is to buy a higher-end model, such as J-Link PLUS, J-Link ULTRA+, or J-Link Pro.

      The same applies to the J-Link Flash Breakpoints technology or the J-Link Debugger Ozone, for instance. Learn more here...

      In order to receive a free 30 days trial license, please send an email including the J-Link serial number to: sales@segger.com.

      Q: What is the advantage of J-Link versus simple probes such as FTDI-based systems?

      A:  J-Link has numerous advantages: Communication is handled by the probe which makes communication more reliable and faster. Flash loaders are provided by SEGGER or can be created using the device support kit. The debug communication interface RTT is available. All popular IDEs include support for the J-Link across all vendors. With an additional license an unlimited number of breakpoints in flash memory can be set. In contrast to most simple probes, J-Link supports adaptive clocking as well as SWD and SWO.

      Q: May I work with more than one J-Link at the same time, on the same machine?

      A:  Yes, you can connect an unlimited number of J-Links to your PC. No special configuration required; each J-Link is registered with its unique serial number on the PC. This enables you to have multiple J-Links connected at once.

      Q: I have multiple Arm cores in my JTAG chain. How can I debug them (simultaneously) with J-Link?

      A:  That's simple: Two or more debuggers can use the same J-Link simultaneously. Multi-core debugging requires multiple debuggers or multiple instances of the same debugger. You need to tell your debugger which device in the scan chain you want to debug. Additional special settings are not required.

      Q: Does J-Link support the Embedded Trace Buffer (ETB)?

      A:  Yes. J-Link supports ETB on Cortex-M3/M4/M7 and Cortex-A/R (if implemented by target device).

      Q: Does J-Link support the Micro Trace Buffer (MTB)?

      A:  Yes.

      Q: Does J-Link support the Embedded Trace Macrocell (ETM)?

      A:  No. ETM requires another connection to the ARM chip and a CPU with built-in ETM. ETM is supported by the J-Trace product family.


      Latest news

      2025
      Sep.11
      J-Link
      J-Link and Flasher next to Geehy G33R50x chip

      SEGGER J-Link and Flasher product families now support Geehy G32R50x MCUs

      SEGGER's market-leading J-Link debug probes and Flasher in-system programmers can now be used with Geehy's G32R50x series of real-time microcontroller units (MCUs).

      [Read more...]

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