SG400 programmer supports Renesas RH850 chip ICU-S function

The ICU-S (Intelligent Cryptographic Unit) function in the RH850 chip is mainly related to the field of automotive safety, especially in the implementation of secure boot. With the strong support of the Renesas China technical team, the OPTEEQ SG400 series programmer has realized the support for the ICU-S function of the RH850 chip.

ICU-S Features

1.Hardware Root of Trust

ICU-S creates a hardware root of trust through OTP (One Time Program) flash memory and protected key storage in ICUS.

2.Tamper resistance

The MAC (Message Authentication Code) and MAC key are securely stored in protected ICUS memory to prevent tampering.

3.Cryptographic Algorithm

ICU-S uses CMAC (NIST SP 800-38B) as the cryptographic algorithm.

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ICU-S Usage Scenarios

1. Secure Boot

• The security software in ICU-S MCUs runs on the main processor element (MainPE) and can use the hardware resources in the ICU-S module, such as cryptographic accelerators and secure key storage, through the special function register interface of the ICUS.
• Secure boot runs from the non-secure CPU (PE1) and the initial secure boot logic is stored in OTP memory to prevent tampering.
• The secure boot program calculates the CMAC value of the user program and compares it with the CMAC value stored in ICUS to verify the integrity of the program.

2. Staged Secure Boot

• In the segmented secure boot example using ICUS on RH850, after the MCU is reset, the CPU (PE1) starts and runs the secure boot program located in the OTP memory, verifies user program A, and then user program B.

3. Automotive Safety Communications

• ICU-S supports the SENT communication standard for transmission of sensor information, and CAN FD (Controller Area Network, Flexible Data Rate) for higher-speed in-vehicle network communication.

4. Functional Safety Implementation

• The RH850/E1M-S2 has many built-in features to achieve functional safety under the ISO 26262 standard, which helps with the certification process.

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Q&A

Q: What is the main usage scenario of ICU-S in RH850 chip?

A: The main use scenario of ICU-S in the RH850 chip is in the field of automotive safety, especially in applications where software integrity needs to be ensured and unauthorized tampering prevention is required, such as engine control units (ECUs) and other key automotive electronic systems. By providing hardware root of trust and anti-tampering protection, ICU-S helps achieve automotive security communications and secure startup, ensuring the safety and reliability of vehicle systems.

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Functions and screenshots implemented on OPTEEQ SG400

Setting up ICU-S:

Read back ICU-S status through engineering

As shown in the figure above, add the following command between the advanced options dev:Init() and dev:UnInit() in the creation process to read back the chip ICU-S status value.