Segger J-Link JTAG Renesas RX support - for Renesas RX cores

Segger JTAG RX

All that is needed to use J-Link with a Renesas RX600 series MCU, is a regular J-Link + the 20-pin to 14-pin RX adapter. The required software can be downloaded from SEGGER’s website and used free of charge.




Supports direct download into flash memory
Supports software breakpoints in flash memory (Flash breakpoints)
Seamless integration into the Renesas HEW & IAR Embedded Workbench IDE
On-chip trace support
Virtual UART support (C2E support)
All kinds of events are supported (Execution break, data access, trace break, combintation/sequentation of events)
20-pin to standard 14-pin Renesas JTAG connector
USB 2.0 interface
JTAG speed up to 12 MHz
No power supply required, powered through USB
All JTAG signals can be monitored, target voltage can be measured
Support for multiple devices
Fully plug and play compatible
Wide target voltage range: 1.2V - 3.3V, 5V tolerant
TCP/IP server included, which allows using J-Link via TCP/IP networks
Target power supply: J-Link can supply up to 300 mA to target with overload protection



  • Getting started

  • Installing the J-Link USB driver


  • J-Link RX is compatible to the regular J-Link and uses the same USB driver. In order to install the driver, simply download and install the latest software and documentation pack of J-Link:


  • In order to verify the correct installation of the J-Link USB driver, simply start J-Link commander, a small command line-based tool which comes with the J-Link software.

  • J-Link commander can be found at Start -> All programs -> SEGGER -> J-Link software version -> J-Link commander. If the installation of the driver was successful and J-Link + target board are connected to the PC, the output of J-Link commander should look like this:



J-link RX


Setup J-Link RX for use in Renesas HEW and IAR EWRX


J-Link RX is fully compatible to Renesas E1 emulator and works with Renesas HEW and IAR Embedded Workbench for RX (EWRX).

The J-Link RX software is a package of DLLs which replace the original Renesas DLLs used for E1/E20 and can be downloaded by emailing us. click here



For more detailed information how to setup J-Link RX for use with HEW and EWRX, please follow the instructions in the Readme.txt which comes with the software package.

Using J-Link RX with Renesas HEW and IAR EWRX


Since J-Link RX is fully compatible to the Renesas E1 emulator, all features supported by the IDE + E1 can also be used with J-Link RX. J-Link RX has been tested with the following IDEs:
Renesas HEW





J-Link RX hardware


RX Adaptor



All that is needed to use J-Link with a Renesas RX600 series MCU, is a regular J-Link + the 20-pin to 14-pin RX adapter.



J-Link vs. Renesas E1. What are the advantages of J-Link ?



Higher speed

First of all, J-Link is much faster. We achive (at the time of writing, using the current versions of both the J-Link and E1 software) a speed of approximately 2-6 times the speed of the E1.
This is true for basically all operations, incl. download to flash, setting of breakpoints in flash as well as startup and typical debugging operations like single stepping or memory read operations.

Smart breakpoint management

Flash breakpoints are much faster on J-Link than on E1 or E20, but because of the large flash sectors of up to 128KB, setting or removing flash breakpoints is still time consuming.
J-Link uses different techniques to minimize the amount of times a flash breakpoint is set or removed. Some of these techniques are: Instruction set simulation, use of hardware breakpoints where possible, dynamic conversion of breakpoint types, flash caching, CRC checking and others

SDK available

You can write your own application and control an RX600 series MCU using J-Link
Same probe for ARM and RX600 CPUs: No need to switch emulators!
Control panel allows monitoring of operation
64 bit OS supported
J-Link commander: Free Command line utility for J-Link
J-Flash: Allows using J-Link for production purposes