Renesas has released the Flexible Software Package (FSP) version 6.5.0 for the RA MCU family. This update brings a notable change to the toolchain ecosystem and expands support for secure boot and high-performance peripherals.
Installation and Prerequisites
The minimum supported version of e2 studio for this release is e2 studio 2026-04.2. Installers for the FSP bundled with e2 studio are available for Windows, Linux, and macOS (Apple Silicon). Renesas also provides the Renesas Advanced Smart Configurator (RASC) installers for the same platforms.
Vendor claim: Future releases of FSP will no longer ship with the GCC toolchain integrated within the combined e2 studio / FSP platform installer. Users can still download GCC via the platform installer or link to an existing local installation.
Toolchain and Optimization Changes
A significant technical shift affects the LLVM toolchain integration. Starting with FSP 6.3.0, the default compiler optimization level for RA4, RA6, and RA8 MCUs is -Os (optimize for size) when using LLVM. This replaces the previous -O2 default. Renesas notes that -Os provides a balance of optimizations similar to GCC's -O2.
For RA0 and RA2 MCUs, where memory size is critical, the default remains -Oz (optimize for size, discard unused code).
New Features
The release introduces several enhancements to middleware and security:
- MCUboot Solution Templates: New templates for single-image and multi-image boot scenarios using MbedTLS. Support includes RA6 CM4 devices, CM33 devices, and the CM85 core, with options for mirrored memory flash (MMF) mode.
- Middleware Updates: LVGL has been updated to version 9.5. Support for the Host Video Class (HUVC) driver and LwIP SNMP application has been added.
- Hardware Support: FSP pin configuration support has been expanded for RA8M1, RA8M2, RA8T1 (169-BGA), RA4L1 (72-WLCSP), and RA0E1 (20-TSSOP).
Fixes and Improvements
Several critical fixes address performance and compatibility issues:
- RA8 D-Cache Support: D-Cache support has been enabled for RA8 devices in the DTC, SPI_B, SCI_B_SPI, and SCI_B_UART modules.
- Motor Control: The
rm_motor_controlandrm_motor_sensormodules have received fixes for unit conversion errors and angle integration issues. - Security: RSIP Protected Mode drivers for E51A and E50D have been optimized for code size. MbedTLS has been updated to version 3.6.6.
Known Issues
Users should be aware of several workarounds required for this release:
- Pin Configuration: There are known issues with pin configuration in e2 studio 2026-04.2. A workaround document is available.
- RA0x Devices: HS400x and ZMOD4xxx sensors cannot be used. The FS3000 sensor does not support the SAU-I2C driver.
- RA0E3 (IAR): EWARM version 9.70.4 does not contain support for RA0E3. A patch file is required.
Third-Party Software
The release bundles updated versions of common embedded libraries, including MbedTLS 3.6.6, FreeRTOS Kernel 11.1.0, and Arm CMSIS 6.1.0.