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Flasher RX

Flash Programmer for Renesas RX cores

Flasher RX is a programming tool for Renesas RX-based microcontrollers with on-chip or external flash memory. Flasher RX is designed for programming flash targets with the J-Flash software or stand-alone. In addition to that Flasher RX has all of the J-Link RX functionality. Flasher RX connects via Ethernet, USB or via RS232 interface to a PC, running Microsoft Windows 2000 or later (for a list of supported versions, please refer to the specifications below). 
Flasher RX itself has a built-in 20-pin JTAG connector but is shipped with a 14-pin adapter for Renesas RX devices. 


  • Stand-alone JTAG programmer (Once set up, Flasher can be controlled without the use of PC program)
  • Support for Renesas RX series CPUs. For a complete list, please click here
  • Supports internal and external flash devices
  • Free software updates1, 2 years of support
  • 64 MB memory for storage of target program
  • Serial in target programming supported
  • Data files can be updated via Ethernet/USB using J-Flash or via the mass storage functionality of Flasher RX
  • Target interface: JTAG
  • No power supply required, powered through USB
  • Can be used as J-Link (JTAG emulator) with a download speed (into RAM) of up to 720 Kbytes/second
  • Programming speed between 30-300 Kbytes/second depending on target hardware
  • ASCII command interface to control Flasher without the use of PC program
  • Authorized Flashing allows to limit the number of flash programming cycles and to protect the Flasher against non-authorized access in case of external production

1As a legitimate owner of a SEGGER Flasher, you can always download the latest software free of charge. Though not planned and not likely, we reserve the right to change this policy. Note that older models may not be supported by newer versions of the software. Typically, we support older models with new software at least 3 years after end of life.

Package content

Flasher RX is delivered with the following components:
Flasher RX RX 14-pin adapter incl. 14-pin flat ribbon cable Ethernet cable RS232 cable 1:1 female / male USB cable USB power supply

Available software

In order to setup Flasher RX for stand-alone operation, you need the J-Flash software from the J-Link software and documentation package. The J-Link software and documentation package is available for download on our website: Software and documentation package download

Supported CPU cores / devices

Flasher RX supports a wide range of cores/devices. For a complete list, please click here



Supported OS Microsoft Windows 2000
Microsoft Windows XP
Microsoft Windows XP x64
Microsoft Windows 2003
Microsoft Windows 2003 x64
Microsoft Windows Vista
Microsoft Windows Vista x64
Microsoft Windows 7
Microsoft Windows 7 x64
Microsoft Windows 8
Microsoft Windows 8 x64
Microsoft Windows 10
Microsoft Windows 10 x64
Operating Temperature + 5 °C ... + 60 °C
Storage Temperature - 20 °C ... + 65 °C
Relative Humidity (non-condensing) < 90% rH
Size (without cables) 121mm x 66mmx 30mm
Weight (without cables) 119g
Available interfaces
USB Host Interface USB 2.0
Ethernet Host Interface 10/100 MBit
RS232 Host Interface RS232 9-pin
Target Interface JTAG 20-pin (shipped with 14-pin adapter for Renesas RX)
JTAG Interface, Electrical
Power Supply USB powered, 100mA for Flasher RX. 500 mA if target is powered by Flasher RX
Target interface voltage (VIF) 1.2 ... 5V
Target supply voltage 4.5V ... 5V (on the 14-pin adapter the target supply voltage can be switched between 3.3V and 5V)
Target supply current max. 400mA
Reset Type Open drain. Can be pulled low or tristated
Reset low level output voltage (VOL) VOL <= 10% of VIF
For the whole target voltage range (1.8V <= VIF <= 5V)
LOW level input voltage (VIL) VIL <= 40% of VIF
HIGH level input voltage (VIH) VIH >= 60% of VIF
For 1.8V <= VIF <= 3.6V
LOW level output voltage (VOL) with a load of 10 kOhm VOL <= 10% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhm VOH >= 90% of VIF
For 3.6 <= VIF <= 5V
LOW level output voltage (VOL) with a load of 10 kOhm VOL <= 20% of VIF
HIGH level output voltage (VOH) with a load of 10 kOhm VOH >= 80% of VIF
JTAG Interface, Timing
Max. JTAG speed up to 12MHz
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 <= 10ns
Clock fall time (Tfc) Tfc <= 10ns

JTAG interface connection (14-pin)

Pin Signal Type Description
1 TCK Output JTAG clock signal to target CPU. It is recommended that this pin is pulled to a defined state on the target board. Typically connected to TCK on target CPU.
3 TRSTn Output JTAG Reset. Output from Flasher RX to the Reset signal of the target JTAG port. Typically connected to nTRST of the target CPU. This pin is normally pulled HIGH on the target to avoid unintentional resets when there is no connection.
4 EMLE Output Pin for the emulator enable signal. This pin must be HIGH to enable the debug interface. Pulled HIGH to VTref via 1k pull-up resistor on 14-pin RX adapter.
5 TDO Input JTAG data output from target CPU. Typically connected to TDO on target CPU.
6 --- NC This pin is not connected to Flasher RX.
7 --- NC This pin is not connected to Flasher RX.
8 VTref Input This is the target reference voltage. It is used to check if the target has power, to create the logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from Vdd of the target board and must not have a series resistor.
9 TMS Output JTAG mode set input of target CPU. This pin should be pulled up on the target. Typically connected to TMS on target CPU.
10 --- NC This pin is not connected to Flasher RX.
11 TDI Output JTAG data input of target CPU. It is recommended that this pin is pulled to a defined state on the target board. Typically connected to TDI on target CPU.
13 nRES I/O Target CPU reset signal. Typically connected to the RESET pin of the target CPU, which is typically called "nRST", "nRESET" or "RESET".
  • All pins marked NC are not connected to Flasher RX. Any signal can be applied here; Flasher RX will simply ignore such a signal.
  • Pins 2, 12, 14 are GND pins connected to GND in Flasher RX. They should also be connected to GND in the target system.

Performance of MCUs with internal flash memory

The following table lists program and erase performance values for different controllers.
Microcontroller Size [kByte] Erase time [sec] Program time [sec] Verify time [sec] Total time [sec]
R5F56108 2048 9.523 11.915 3.890 25.585