RX261 Fast Prototyping Board

Overview

The FPB-RX261 is a Fast Prototyping Board for the Renesas RX261 MCU Group, designed to evaluate features of the RX261 family and accelerate embedded system development. The board includes native MCU pin access, integrated debugger, power flexibility, and expansion connectors.

The key features of the FPB-RX261 board are categorized in two groups:

MCU Native Pin Access

  • R5F52618BGFP MCU

  • 64 MHz Renesas RXv3-based RX261 MCU in 100-pin LFQFP package

  • 512 KB Code Flash, 8 KB Data Flash, 128 KB RAM

  • Native pin access through 2 x 50-pin male headers (not fitted)

  • MCU current measurement point for precision current consumption measurement

  • RX MCU on-chip oscillators as main clock

  • Providing 32.768 kHz crystal oscillator as sub clock

System Control and Ecosystem Access

  • 5V input sources:

    • USB (USB DEBUG1 - J5)

    • External 5V via 2-pin header (J8)

  • On-board debugger via E2 Emulator OB (FINE interface)

  • User LEDs:

    • 2 Green User LEDs (PJ1, PC5)

    • 1 Green Power LED

    • 1 Yellow Debug LED

  • User Buttons:

    • 1 User Switch (S1 - P32)

    • 1 Reset Switch (S2)

  • Popular expansion connectors:

    • 2x Digilent Pmod connectors (J13, J14 - UART/SPI/I2C)

    • Arduino Uno R3-compatible header (J9-J12)

Hardware

Detailed hardware features can be found at: - RX261 MCU: RX261 Group User’s Manual Hardware. - FPB-RX261 board: FPB-RX261 - User’s Manual.

Supported Features

The fpb_rx261 board supports the hardware features listed below.

on-chip / on-board
Feature integrated in the SoC / present on the board.
2 / 2
Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo
Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

Other hardware features are currently not supported by the port.

Programming and Debugging

The fpb_rx261 board supports the runners and associated west commands listed below.

flash debug

Applications for the fpb_rx261 board can be built, flashed, and debugged using standard Zephyr workflows. Refer to Building an Application and Run an Application for more details.

Note: Currently, the RX261 is built and programmed using the Renesas GCC RX toolchain. Please follow the steps below to program it onto the board:

export ZEPHYR_TOOLCHAIN_VARIANT=cross-compile
export CROSS_COMPILE=<Path/to/your/toolchain>/bin/rx-elf-

  • Build the Blinky Sample for FPB-RX261

cd ~/zephyrproject/zephyr
west build -p always -b fpb_rx261 samples/basic/blinky

Flashing

The program can be flashed to FPB-RX261 via the on-board E2 Emulator OB.

  1. Connect the board:

    • Use USB DEBUG1 (J5) to connect the on-board E2 Emulator to the PC

  2. Configure jumpers for flashing:

    • J4: Jumper on pins 2-3 (enable E2 OB)

    • J7: Jumper on pins 1-2 (3.3V system voltage)

  3. Run flashing command:

    west flash

    Or use Renesas Flash Programmer with settings: - Debugger: E2 Emulator Lite - Interface: FINE - MCU: R5F52618

Debugging

Debugging is supported via:

  • On-board E2 Emulator OB using USB DEBUG1 (J5)

To use debugger:

  • J4: Jumper on pins 2-3 (enable E2 OB)

  • J7: Jumper on pins 1-2 (3.3V)

  • LED4 (Yellow) indicates debugger status

Note: Only one FPB-RX261 board can be debugged per PC at a time using E2 OB.

References