The YTM32B1H and YTM32B1M series are functional safety microcontroller families based on the ARM Cortex-M architecture, certified to ASIL D safety integrity level. Designed for harsh electrical environments and cost-sensitive applications, they provide low-pin-count configurations and extensive memory/peripheral resources.

Both series feature unified peripheral interfaces and pin layouts, enabling seamless portability across intra-/inter-series MCUs. This scalability allows developers to standardize chip selection for end-product platforms, maximizing software-hardware reuse and accelerating time-to-market.

ZC-YunTu SafLib is a functional safety software library jointly developed by Shanghai ZhiCong Technology Co., Ltd. and Jiangsu YunTu Semiconductor Co., Ltd. It is developed in accordance with the AUTOSAR CDD (Complex Driver) module specification and complies with the AUTOSAR CP v4.4 standard requirements. It supports startup phase (Startup) and runtime (Run-Time) testing.

SafLib is a functional safety software library that implements safety mechanisms through software to detect hardware product failures. It provides multiple detection modules, such as SRAM ECC self-check, FLASH ECC self-check, kernel self-check, clock self-check, DMA self-check, and internal watchdog self-check, to monitor and prevent hardware failures at a low cost. It is widely adopted by chip manufacturers as a supplementary solution to hardware safety measures.

Toolchain support

Publication method

SafLib offers two versions: a free version and a paid version.

l  Free QM version

Includes only code, sample projects, and QM documentation (User Manual, QSG, and Release Note), with free upgrades available.

l  Paid ASIL-B/ASIL-D Version

Based on the QM version, it adds a Safety Package. This includes the Safety Manual, SW DFA, product certificates, external third-party assessment reports, technical support (basic services and system integration), and product-level functional safety certification support.

The SafLib can be applied to controllers that require functional safety levels.

For example:

Ø  Motor Controller

Ø  Battery Management System(BMS)

Ø  Chassis System Applications

Ø  Electronic Stability Control(ESC)

Ø  Electric Power Steering(EPS)

Ø  Chassis Domain Line Control System Applications

Ø  Radar Applications

By integrating the Safety Library into the control based on YTM32B1M/H, it is possible to meet the ISO 26262 ASIL-B (up to ASIL-D) level requirements.

Currently, the electronic and electrical architecture of automobiles is becoming increasingly complex, and the safety requirements for automotive electronics are also rising. To meet the safety requirements of automobiles, functional safety is gaining more attention. When it comes to functional safety, the first thing that comes to mind is the functional safety standard ISO 26262. In particular, ISO 26262-5(2018) Clause 8 introduces two metrics: Single-point fault metric (single-point fault metric) and Latent-fault metric (latent fault metric). Depending on the required ASIL level, the single-point fault metric and latent fault metric must meet the corresponding levels.

For microcontrollers (MCU, referred to as MCU below), within the electronic and electrical system, they are designed and developed as SEooC (safety element out of context). To meet the aforementioned metric requirements, MCUs need to implement corresponding safety mechanisms. These safety mechanisms can be allocated to both hardware and software modules. The SafLib for MCUs is the implementation of safety mechanisms allocated to software.

SafLib Software Architecture Diagram

Ø  Can be integrated as a complex driver into AUTOSAR .

Ø  Can be integrated into non-AUTOSAR software architectures.

Ø  High Safety: It can achieve up to ASIL-D requirements when paired with SafLib.

Ø  High scalability: Each module can be configured to meet the application requirements of different customers.

The following are the modules included in SafLib. The components used vary slightly depending on the MCU:

SafLib Component List

1.1.1        Cortst

CorTst is a basic software module used in the AUTOSAR standard to test the core functions of microcontrollers. The YunTu M series MCU core is based on CM33 core. Since the hardware does not have sufficient functional safety mechanisms, CorTst software measures are used to detect failures in critical internal circuits of the CPU.

l  Support for startup testing (front-end testing)

l  Supports runtime testing (background testing)

l  Permanent failure covering the CM33 core

1.1.2        RamTst

RamTst is a module related to memory testing for BSW MCAL in the AUTOSAR standard. It works by using different algorithms to test the physical health of RAM memory cells.

l  Achieve three levels of detection coverage requirements: low (60%), medium (90%), and high (99%).

l  Single-point fault detection and diagnosis covering the YTM32 series on-chip SRAM

1.1.3        FlsTst

FlsTst is a module related to MCAL memory testing in the AUTOSAR standard, which provides algorithms for testing non-volatile memory. FlsTst is designed to test the integrity of the flash contents.Test results are based on a CRC comparison between the computed CRC value and an expected CRC value.

l  Independent testing of each partition

l  Supports startup testing (foreground testing)

l  Supports runtime testing (background testing)

l  Supports CRC8, CRC16, and CRC32 algorithm selection

1.1.4        StkTst

The StkTst (Stack Test) module detects stack overflows by calculating the checksum of the stack detection area and comparing it with the expected original value to verify stack integrity.

l  Supports stack overflow detection with OS

l  Supports startup testing

l  Supports runtime testing

l  Covers YTM32 series runtime system failure detection and diagnosis

1.1.5        EfmTst

EfmTst is used for self-testing of EFM (flash controller) protection functions, including write protection mechanism detection, command unlock function, and write enable protection.

l  Supports startup testing

l  Can cover potential fault detection and diagnosis of the erase and program protection function safety mechanisms of YTM32 series FLASH memory

1.1.6        EccTst

EccTst provides memory ECC self-test services to detect permanent failures in on-chip memory hardware ECC, including Flash ECC, SRAM ECC, and CAN message buffer RAM ECC. These different memories have different ECC implementations and availability on YTM32 devices.

l  Supports boot testing

l  Covers potential fault detection and diagnosis of ECC in various functional safety-related memory types across the YTM32 series of MCUs.

1.1.7        DmaTst

The DmaTst module was developed for self-testing of DMA (Direct Memory Access) functions and serves as an important software security mechanism for the secure transfer of critical data between memory (flash memory and SRAM) and peripherals or between memory locations.

l  Supports startup testing (self-testing of the DMA channel error detection mechanism)

l  Supports runtime testing (data transfer functionality testing, requiring 1/2 DMA channel)

l  Covers single-point fault detection and diagnosis for the YTM32 series DMA modules

1.1.8        PpuTst

The PpuTst module is a software security measure that tests the protection capabilities of the hardware PPU module. The PPU (Peripheral Protection Unit) module is used to protect defined memory-mapped addresses. It protects critical configuration registers from accidental modification.

l  Supports startup testing

l  Covers potential fault detection and diagnosis of YTM32 series PPU modules

1.1.9        IntTst

IntTst is used to test the INTM (interrupt monitor) module, which monitors and detects faults related to safety-critical peripheral IRQ interrupt latency timeouts.

l  Supports monitoring of up to four peripheral interrupts

l  Supports startup testing

l  Covers potential fault detection and diagnosis of YTM32 series INTM modules

1.1.10     ClkTst

ClkTst is used to detect whether the CMU (clock monitoring unit) is functioning normally. The CMU monitors various reference/functional clock anomalies required for the operation of the system and peripheral modules, including clock loss of the calibration clock, clock loss of the reference clock, and frequency deviation of the calibration clock.

l  Supports startup testing

l  Covers potential fault detection and diagnosis of YTM32 series CMU modules

1.1.11     CrcTst

CrcTst is used to test the functionality of the CRC/PCRC module and check the integrity of the register configuration.

l  Supports startup testing (CRC self-test)

l  Supports runtime testing (peripheral/configuration register data consistency check)

l  Covers latent fault detection and diagnosis of the YTM32 series CRC module

1.1.12     WdgTst

There are two types of devices on the YTM32

1.    WDG (internal watchdog) is a standard 16/32-bit watchdog timer that supports window mode and only monitors the internal CPU core.

2.      EWDG (External Watchdog) is an 8-bit watchdog timer that can simultaneously monitor the internal CPU core and external safety-critical input signals. Even if the internal CPU becomes stuck, it can trigger an ECU system reset or output control signals as system-level safety measures to the system-level safety manager.

l  Supports both internal and external watchdog functions

l  Supports startup testing

l  Can cover potential fault detection and diagnosis for both the internal and external watchdogs of the YTM32 series

1.1.13     FmuTst

FMU is a module that centrally collects and processes errors on the chip, and is only supported by the Hx series. The FmuTst module is used to verify the functionality of the FMU to ensure it operates properly in subsequent safety applications.

l  Supports detection of FMU register lock and access protection functionality

l  Supports FMU configuration state fault injection testing

l  Supports verification of FMU alarm functionality

l  Supports verification of FMU NMI functionality

l  Supports verification of FMU error signal output functionality

l  Supports verification of FMU external error signal input functionality

l  Supports startup testing

l  Can cover potential fault detection and diagnosis for FMU modules in the YTM32H series

Introduction to the YCT Configuration Tool

YunTu YCT is a one-stop user interaction platform developed by YunTu that supports software (SDK/MCAL/SafLib) configuration, code and application engineer generation, application development, file download, UDS, OTA, and other functions for YunTu's automotive-grade MCU products.

YCT Configuration Tool UI Interface

Introduce to the ZC.MuNiu Configuration Tool

The ZC.MuNiu Configuration Tool is developed based on the latest ARTOP architecture and supports the latest AUTOSAR R21-11 standard as a basic software configuration tool, providing comprehensive BSW configuration and RTE generation functions. Currently, ZC's AUTOSAR-standard BSW, complex drivers, SafetyFrame, CryptoLibrary, and other basic software products all utilize this configuration tool. This solution is compatible with industry-standard specifications, including system functional design, ECU functional mapping, component configuration, and automatic code generation for runtime environments, providing a proven foundation for developing reusable ECU application software. It can be used in conjunction with tools such as Vector and EB.

ZC.MuNiu Configuration Tool UI Interface

YTM32B1MCx ASIL-B Certificate

YTM32B1ME0x/MD1x ASIL-B Certificate

YTM32B1HA0x ASIL-D Certificate

YT SafLib ASIL-D Certificate

Click to download the product manual