RA Flexible Software Package Documentation  Release v4.3.0



This manual describes how to use the Renesas Flexible Software Package (FSP) for writing applications for the RA microcontroller series.

Using this Manual

This manual provides a wide variety of information, so it can be helpful to know where to start. Here is a short description of each main section and how they can be used.

Starting Development - Provides a step by step guide on how to use e2 studio and FSP to develop a project for RA MCUs. This is a good place to start to get up to speed quickly and efficiently.

FSP Architecture - Provides useful background material on key FSP concepts such as Modules, Stacks, and API standards. Reference this section to extend or refresh your knowledge of FSP concepts.

API Reference - Provides detailed information on each module and interface including features, API functions, configuration settings, usage notes, function prototypes and code examples. Board Support Package (BSP) related API functions are also included.

Much of the information in the API Reference section is available from within the e2 studio tool via the Developer Assistance feature. The information here can be referenced for additional details on API features.

Documentation Standard

Each Modules section user guide outlines the following:

  • Features: A bullet list of high level features provided by the module.
  • Configuration: A description of module specific configurations available in the RA Configuration editor.
  • Usage Notes: Module specific documentation and limitations.
  • Examples: Example code provided to help the user get started.
  • API Reference: Usage notes for each API in the module, including the function prototype and hyperlinks to the interface documentation for parameter definitions.

Each Interfaces section user guide outlines the following:

  • Detailed Description: A short description and summary of the interface functionality.
  • Data Structures: A list and definition of each data structure used by the interface including the structure of the pointers that define the API and are shared by all modules that implement the interface.
  • Typedefs: A list and description of the typedefs used by the interface.
  • Enumerations: A list and description of the enumerations used by the interface.

Introduction to FSP


The Renesas Flexible Software Package (FSP) is an optimized software package designed to provide easy to use, scalable, high quality software for embedded system design. The primary goal is to provide lightweight, efficient drivers that meet common use cases in embedded systems.


FSP code quality is enforced by peer reviews, automated requirements-based testing, and automated static analysis.

Ease of Use

FSP provides uniform and intuitive APIs that are well documented. Each module is supported with detailed user documentation including example code.


FSP modules can be used on any MCU in the RA family, provided the MCU has any peripherals required by the module.

Build Time Configurations

FSP modules also have build time configurations that can be used to optimize the size of the module for the feature set required by the application.

e2 studio IDE

FSP provides a host of efficiency enhancing tools for developing projects targeting the Renesas RA series of MCU devices. The e2 studio IDE provides a familiar development cockpit from which the key steps of project creation, module selection and configuration, code development, code generation, and debugging are all managed.