Renesas has announced the “RX Functional Safety” solution for industrial applications that reduces the complexity of IEC 61508 Safety Integrity Level 3 (SIL)​ certification, an international standard for functional safety.

Based on the RX family of microcontrollers (MCUs), the new solution provides advanced functional safety for industrial equipment, including functions for chip self-diagnostics, the world’s first SIL3-certified functional safety software and reference documents for users to develop the safety part of industrial applications, says Renesas. The complete functional safety support for industrial applications allows users to shorten the certification acquisition process by a year or more.

Featuring a dual-MCU configuration, the RX Functional Safety will support all Renesas MCUs based on the RXv2 core to enable simple safety verification and an efficient diagnostics software. With the SIL3-certified software, the solution eliminates the need for users to develop functional safety software dependant to Renesas MCUs and allows them to focus on development of software for their own application components.

When starting on a new functional safety system, developers face a large number of difficult technological problems, including the interpretation of difficult standards, acquiring methods for constructing dual-structure MCUs, and selecting third parties for support. Users experienced in configuring functional safety systems are also challenged with development burdens such as acquiring software certification and the recertification associated with the expansion of system functions.

To resolve these issues, Renesas has developed a software based solution combining:

  • RX Functional Safety – Self-Test Software Kit: performs self-diagnostics at the individual MCU level
  • Self-diagnostics software library*
  • Safety manual*
  • User guide*
  • RX Functional Safety - SIL3 System Software Kit: achieves the world's first SIL3 certification by performing required mutual diagnostics in a dual MCU architecture structure and a function that isolates multiple software applications to implement functional safety
  • Functional safety platform software*
  • Safety manual*
  • User guide*
  • IEC 61508 SIL3 certification documents (certification document, test report)
  • Software development handbook
  • Configuration tool for generating and evaluating configuration files that set up the functional safety platform software and set user application behaviour
  • Configuration tool manual

Asterisks (*) indicate items that have received IEC 61508 SIL3 certification from TÜV Rheinland.

  • RX Functional Safety - Reference Hardware: dual-structure MCU evaluation board using the RX71M and RX651 MCUs and related technical documentation (manuals, circuit diagrams, parts lists, and other items)
  • RX Functional Safety - Reference Documents: technical documentation to help developers acquire SIL3 certification for their applications.

The new solution features the first SIL3-certified software that includes mutual diagnosis that presupposes a dual MCU structure and software isolation functions (safe and non-safe isolation functions) that isolate multiple application software programs from affecting each other. In situations where software changes occur in association with deployment to multiple versions, the software isolation function allows certification of only the software sections that have changed. This can significantly reduce the time required for recertification application and certification application itself, reducing the burdens involved in developing dual-MCU configuration systems.

Application software not related to functional safety – such as the system control software and safety monitoring software – can be embedded in a single MCU using the software isolation function, minimising the need for additional devices for safety monitoring.