Enroll to Review the Renesas RX671 MCU Eval Kit

Table of contents

The RX671 group of 32-bit microcontrollers (MCUs) is a high-performance, single-chip solution with touch sensing and voice recognition capabilities for contactless operation. It's a great choice for space-constrained applications or other use cases such as, heating, ventilation, and air conditioning (HVAC), smart meters, and smart home appliances.


The EK-RX671 is the evaluation kit for the Renesas RX671 MCU group. This kit comes with all the HW and SW needed to start evaluation immediately after unboxing. In addition, it can be combined with various expansion boards to easily expand the board's functionality. On-board HMI application target function: 2 capacitive touch buttons, Audio Interface with MEMS micros and 3.5mm headphone jack enable to evaluate HMI functions. It’s compatible with the most popular ecosystem expansions such as MikroElektronikaTm mikroBUS connector, SparkFun® Qwiic® connector, two SeeedGrove® system connectors, two Digilent PmodTm (SPI/UART/I2C) connectors and ArduinoTm (Uno R3) connector.

The RX671 group of 32-bit microcontrollers (MCUs) is a high-performance, high-functionality single-chip solution with touch sensing and voice recognition capabilities for contactless operation. Part of Renesas’ mainstream RX600 Series, the RX671 MCUs are built around an RXv3 CPU core operating at 120 MHz and integrates flash memory supporting fast read access at a clock speed of 60 MHz, for excellent real-time performance with a CoreMark score of 707, and power efficiency among the best in the class at 48.8 CoreMark/mA.

Available in a wide variety of packages with pin counts ranging from 48 to 145 pins with up to 2 megabytes (MB) of flash memory and 384 kilobytes (KB) of SRAM, the RX671 MCUs are well suited for a wide range of applications that require advanced functionality, power efficiency, and compact size, such as heating, ventilation, and air conditioning (HVAC), smart meters, and smart home appliances. For size-constrained devices that require advanced functionality, the RX671 is available with 2 MB of flash memory in a 64-pin TFBGA package measuring only 4.5 mm × 4.5 mm – among the smallest anywhere among MCUs with 2MB flash memory.


Ecosystem & System Control

  • USB Full Speed host and device
  • USB-Serial Converter Interface

Multiple 5V input sources

  • USB (Debug, Full Speed)
  • External power supply

E2 OB on-board programmer and debugger
Debug modes

  • Debug On-board (FINE) – via E2 OB
  • Debug In (JTAG or FINE Interface)

User LEDs and buttons

  • Three user LEDs (red, blue, green)
  • Power LED (white) indicating availability of regulated power
  • Debug LED (yellow) indicating the debug connection
  • Two user buttons
  • One reset button

Five most popular ecosystem expansions

  • MikroElektronikaTm mikroBUS connector
  • SparkFun® Qwiic® connector
  • Two SeeedGrove® system (I2C and Analog) connectors
  • Two Digilent PmodTm (SPI/UART/I2C) connectors
  • ArduinoTm (Uno R3) connector

MCU mode configuration switch
Special Features

  • Audio Interface
  • 128Mb SDRAM
  • 64Mb External Quad-SPI Flash
  • MicroSD Card Slot
  • 2 Capacitive Touch Buttons

MCU Native Pin

  • R5F5671EHDFB MCU
  • 120MHz, RXv3 core
  • 2MB Code Flash, 384KB SRAM
  • 144 pins, LFQFP package
  • Native pin access through male pin headers
  • MCU current measurement


Product Variants

This datasheet provides detailed information on the RX671 Group. Click here to view it.


  • EK-RX671 board
  • Micro USB device cable (type-A male to micro-B male)
  • Micro USB host cable (type-A female to micro-B male)

RoadTest Goals

Working with the documentation, open the box and test the out of the box experience. Show us what you discovered through text, images, videos, and/or any other media, so the reader understands what is involved in using the product.

Important Dates

Begin enrollment: Oct 11, 2023
End enrollment:  Nov 15, 2023
Select roadtesters:  Nov 20, 2023
Ship unit:  TBD
Begin Roadtesting: TBD
Element14 follow up: TBD
Post Reviews by:  TBD

About Renesas Electronics Corporation

Renesas Electronics Corporation (TSE: 6723) delivers trusted embedded design innovation with complete semiconductor solutions that enable billions of connected, intelligent devices to enhance the way people work and live. A global leader in microcontrollers, analog, power, and SoC products, Renesas provides comprehensive solutions for a broad range of automotive, industrial, Infrastructure, and IoT applications. Learn more at renesas.com.

Renesas Products

Terms and Conditions

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Comment List
  • I have seen this interesting boards few days ago. This is first board with RX family MCU (containing Renesas Proprietary RX core) in this form factor. All previous EK- boards used RA (ARM) MCUs. But renesas violated some rules which made boards with RA microcontrollers unique. For example there are chips in MCU native areas, newly there are capacitve touch buttons, but in opposition these cost the space which on RA board is used for exposing ALL pins of MCU. Here it seems that only some of them are exposed in MCU native area. Ecosystem area remained almost the same, but replacement of compact ARM debugging connector by huge RX debugging connector is quite funny at the first look. It also seems that they removed debug out feature which on EK-RA boards allow flashing and debugging Renesas MCUs on external (usualy own) board. It seems that Renesas strategy is still selling classic debug probes and on EK-RA boards they offer it just because competitiors also do. At last, board is better priced than EK-RA2L1 which I roadtested few years ago (both cost almost the same, but RX671 offers much more features of course). In this case the price seems resonable to me.

    I recommend applying to anyone. These are very interesting boards and I like them very much. I most probably skip because I recently get RX72N Envision kit containing MCU from similar family, but some features still attract me to apply and give additional try.