Choose the right storage for your smart car

From manual driving to assisted driving to fully automatic driving, society is turning everything that is manually controlled to electronic control. Especially in the past two years, there are more and more cars with L3 or even higher levels, and the distance between automatic driving and reality is just a "small step".

Briefly explain what L0, L1, L2, L3, L4, and L5 levels are: There are currently two main standards for the classification of automatic driving levels. One is formulated by NHSTA (National Highway Traffic Safety Administration) under the U.S. Department of Transportation, and the other is formulated by SAE International (Society of Automotive Engineers). Generally speaking, people still use SAE to distinguish.

Looking at the entire market, how many complex functions are currently equipped in cars? Automatic parking, collision warning, active braking, ACC adaptive cruise, VSA car networking inspection, ISA electronic police system, TMC real-time traffic system, 360 surround view, lane assist, LDWS lane departure warning system, HMW vehicle distance detection and warning, FCWS front vehicle collision warning system, PED pedestrian detection, lane keeping system...

What is the most important thing for smart cars? It is a quick response without any delay, a millisecond opening experience, and a seamless interaction. With the expansion of data volume, in addition to computing power, the storage medium where the data itself is located is the primary factor affecting these.

The question is, do you know how to choose memory? The following memory chip supplier Yingshang International Co., Ltd. introduces some memory chips used in automotive applications.

MRAM

MRAM involves automotive applications. For crash recorders, MRAM can collect and store more data when an accident occurs and help determine the cause of a vehicle accident or failure.

Automotive applications that use sensors can benefit from MRAM. Since sensors continuously write data, flash memory has difficulty maintaining this data flow. New airbag systems also have sensors that detect and record the weight of passengers, interaction with other safety devices on the vehicle, and the impact of a collision.

Other automotive systems, such as odometers, tire pressure recorders, and ABS, require frequent writes to memory that can easily exceed the write-erase capabilities of flash memory and exhaust its memory. MRAM’s unlimited write cycle capability ensures a more reliable system for mission-critical devices such as airbags and ABS.

FORWARD

The VCU system needs to record the current state of the car's driving and the transmission gear, acceleration, braking and output torque information at a rate of once per second. The FRAM technology can be stored and read through relatively simple software, while ensuring high speed and reliability. For example, Fujitsu's automotive standard product MB85RS2MLY has a read and write frequency of up to 10 trillion times, ranging from -40°C to +125°C, which is very suitable for applications that require real-time data recording (for example, recording 0.1 seconds of data every day for 10 consecutive years, the number of writes will exceed 3 billion times), with extremely high data writing stability and reliability.

These characteristics are equally important for BMS (battery management system), another core technology of new energy vehicles. The battery management system needs to record and store data in real time. The system will record important battery data (fault information, health status SOH and power measurement SOC, etc.) in real time and continuously at a frequency of one second or every 0.1 second, while monitoring the short-term (60 times/second for the last few charging cycles) and long-term (the entire life of the battery) performance of the battery. For example, under normal circumstances, the battery pack's power is maintained at 30%~75%, indicating normal operation. If there is an imbalance, it needs to be supplemented from other battery packs. At this time, the system needs to detect and record the battery pack's power, temperature, voltage, current , and other data, and the monitoring and recording time should not be too long.