Renesas Electronic s is hoping to ease the safety design complexities for automotive chassis systems with its new RH850/P1x Series of 32-bit MCUs certified to ASIL-D standards.
The new MCUs combine a 40nm CMOS process with the company's MONOS flash memory structure and are for use in power steering (EPS), brake systems, and other chassis systems.
“Designing for automotive safety is becoming more complex, particularly in chassis systems for mission-critical steering and braking control,” said Amrit Vivekanand, vice president of automotive, Renesas Electronics America. “Today, most chassis systems are now required to meet ASIL D1 – the highest safety level under the ISO 26262 functional safety standard for automobiles – which adds more time, expertise, and resource demands to an already complicated development cycle,”
In addition to the new RH850/P1x series, Renesas Electronics is developing a kit that combines an RH850/P1x Series MCU (single-power-supply version) and the RAA270005KFP power control IC to reduce the power supply design burden significantly. The power control IC integrates trackers for the power supply required by the RH850/P1x Series MCU (single-power-supply version) and for two external sensor power supplies, as well as a variety of monitoring and self-diagnostic functions.
He said the RH850/P1x Series has integrated a set of fault-detection functions including a lockstep system by which an error checking and correcting (ECC) function detects and corrects data errors affecting memory, such as flash memory. There are also fault-detection functions that allow system-level diagnostics of the timers, ADC, serial communication, and other modules.
A built-in self-test (BIST) function detects faults affecting the fault-detection functions themselves. The error control module (ECM) allows users to manage error signal input from the various modules. Upon receiving an error signal the ECU, has a variety of options including, setting an error pin output, generating interrupts or the generation of resets, thereby helping to assure both safety and reliability concerns can be addressed.
In addition to this array of diagnostic functions, said Vivekanand, the RH850/P1x Series can be used as part of a kit including a dedicated power control IC that allows monitoring of power supplies external and internal to the MCU, and reset control in case of malfunction.
The MCUs incorporate two units of the TSG3 (Timer S Generation 3), an enhanced motor control timer designed to improve the motor control performance of chassis systems. For serial communication, the MCUs retain the CAN protocol engine of previous designs and adds to it RS-CAN, which increases the number of transmit and receive message buffers while incorporating improvements that make the buffers easier to use. Finally, the widely adopted SENT and PSI5 are provided as digital interfaces for sensors.