The following content in this page describes current Zephyr support status for Renesas RH850 Automotive MCU family, for detail about RH850 MCUs, please visit RH850 Automotive Microcontrollers (MCUs)

Table of contents

• Table of contents
• Overview
  • System Requirements
  • Supported Device List
  • Supported Board List
  • HWIP and Driver List
• Build and Flash guideline
• Limitations
• Next Release

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Overview

This page describes the content of Renesas RH850 MCU Zephyr components, restrictions and points for caution. This product is an Alpha version of the product under development. Please read the following notes carefully before using this product.

Latest release tag: wip_rh850_260511

System Requirements

The Renesas RH850 MCU is currently supported on Zephyr latest.

Supported Host OS

• Ubuntu version 24.04 LTS and later
• Windows 10 or 11

Development Environments

For development environment setup, please refer to the Getting started.

For getting the Zephyr source code step, please use the following command instead of the default west initialization command to get wip_rh850 repository:

• Replace: west init ~/zephyrproject,
• by: west init -m https://github.com/renesas/zephyr.git --mr wip_rh850

Additional Software Preparation:

• Download and install a release v3.20.1 or newer of IAR toolchain for RH850: https://www.iar.com/embedded-development-tools
• Download and install Renesas Flash Programmer: https://www.renesas.com/en/software-tool/renesas-flash-programmer-programming-gui

NOTE:

• Please make sure that the installed softwares are added into environment PATH
• IAR tool chain is commercial of toolchain suit so please register IAR license before to use it in this product. Please refer below related IAR toolchain:
  • https://www.iar.com/support/iar-educational-license/
  • https://docs.zephyrproject.org/latest/develop/toolchains/iar_arm_toolchain.html

Work In Progress (WIP) branch

Branch name	Information
ZephyrOs:wip_rh850	Includes Zephyr OS, device drivers, board support, and related components.
hal_renesas:wip_rh850	Includes the HAL layer of Renesas RH850 Automotive MCU FSP source code

Supported Device List

Group name	Number of pins	Chip Part Number/SoC Name
RH850 U2B10	468	R7F70254xAFABG-C
RH850 U2B10	468	R7F70254xFABG-C
RH850 U2B10	292	R7F70254xAFABB-C
RH850 U2C8	292	R7F702600AFABB-C
RH850 U2C8	292	R7F702600FABB-C

Supported Board List

Board name (Zephyr board name)	Status	Samples and demo Hardware connection
Y-RH850-U2B-292PIN-PB-T1-V1 (pb_rh850u2b_292pin)	Available on Renesas wip_rh850 branch	RH850-U2B-292PIN Sample and Demo hardware configuration
Y-RH850-U2B-468PIN-PB-T1-V1 (pb_rh850u2b_468pin)	Available on Renesas wip_rh850 branch	RH850-U2B-468PIN Sample and Demo hardware configuration
Y-RH850-U2C-292PIN-PB-T1-V1 (pb_rh850u2c_292pin)	Available on Renesas wip_rh850 branch	RH850-U2C-292PIN Sample and Demo hardware configuration

HWIP and Driver List

Renesas HW IP	Mapping to Zephyr	Status	Board
I/O Ports	GPIO Pinctrl	Available on Renesas wip_rh850 branch	All available devices
RLIN3 (UART)	UART	Available on Renesas wip_rh850 branch	All available devices
OSTM	System Timer	Available on Renesas wip_rh850 branch	All available devices
External Interrupt	Interrupt Controller	Available on Renesas wip_rh850 branch	All available devices
Ethernet T1S	Ethernet	Available on Renesas wip_rh850 branch	only RH850 U2C8
Ethernet PHY	Ethernet	Available on Renesas wip_rh850 branch	only RH850 U2C8

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Build and Flash guideline

Following steps are required for build and flashing Zephyr binary image to Renesas RH850 MCU U2x board.

Currently RH850 arch hasn't support on Zephyr SDK yet, so we need to setup IAR RH850 toolchain.

Build environment setup:

• Set Zephyr toolchain variant to IAR: $ export ZEPHYR_TOOLCHAIN_VARIANT=iar

• Export IAR toolchain PATH for Zephyr build system: $ export IAR_TOOLCHAIN_PATH=<path/to/your/rh850>

  e.g

  $ export IAR_TOOLCHAIN_PATH=/opt/toolchains/IAR/ewrh850-3.20.1/bin/rh850

Build command:

• When executing the build command on a different board, replace the board name/SoC name (pb_rh850u2b_292pin/r7f70254xafabb-c) with the corresponding target values.

  • Please refer to the Supported Device List table for the list of supported SoC name.
  • Please refer to the Supported Board List table for the list of supported Board name.

  e.g: $ west build -b pb_rh850u2b_292pin/r7f70254xafabb-c -p always samples/hello_world

• Once the build is completed successfully, apply the common flash command as described below:

Flash command: $ west flash -- --tool-opt="-auth id FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF -osc 20“

Samples

Refer to the “RH850 Sample and Demo Hardware Configuration” section in the sidebar for instructions on executing the sample for each board.

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Limitations

No	Item	Description of limitations
1	UART	When running at a baud rate of 1 Mbps, the processing time is slower than the rate at which new bytes are received, causing an overrun error.

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Next Release

Relase version	Relase date	Release Scope
U2x Beta1 release	June 30 2026	Supported Devices: - RH850 U2A16: R7F702300BEBBC, R7F702300EBBG-C, R7F702300AEBBC-C. Device Drivers: Counter, SPI, I2C, CRC ADC, WDG, CAN, DMA, PWM, RTC, PIC, Clock Control. Supported Boards: - Y-RH850-U2A-516PIN-PB-T1-V1 (pb_rh850u2a_516pin).