TI has integrated it! CAN FD strengthens and upgrades automotive neural networks

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TI has integrated it! CAN FD strengthens and upgrades automotive neural networks [Copy link]

The CAN FD communication protocol is designed based on the original CAN bus standard (also known as "Classic CAN"), helping to ensure that automotive microcontrollers and connected systems can communicate efficiently at a variety of rates while multiple in-vehicle network data rates and throughputs continue to evolve. The CAN FD protocol supports data rates up to 5 Mbps and payloads up to 64 bytes, effectively improving designers' ability to move data faster in their next-generation automotive applications.

What is CAN FD?

With the rapid development of electronics, semiconductors, communications and other industries, the demand for automotive intelligence is becoming stronger and stronger. In order to improve the safety and comfort of automobiles, realize the electrification and intelligence of automobiles, and enhance network connectivity, automobile manufacturers have integrated more and more functions into automobiles. The large increase in ECUs (electronic control units) has caused a sharp increase in bus load rates.

Currently, the in-vehicle network CAN (Controller Area Network) is widely used in commercial vehicles on the market. However, since the maximum transmission rate of the CAN bus is 1Mbit/s (usually the actual maximum rate of the automotive CAN system is 500kbit/s), the large increase in ECUs has caused a sharp increase in the bus load rate, resulting in network congestion, affecting the reliability and real-time performance of information transmission. In order to meet the growing demand for automotive networks, we need a high-speed in-vehicle network that can transmit more information.

Therefore, in 2012, Bosch released the CAN FD (CAN with Flexible Data rate) protocol, an alternative bus to CAN.

Design advantages of CAN FD

First of all, in terms of transmission rate, CAN FD is faster than CAN. ECU is the brain of the car. If the number of ECUs increases significantly, the processor ROM capacity will also increase. When developing ECUs, the software needs to be written into ROM, and this writing process is completed through CAN. However, it takes a very long time to rewrite large-capacity software through CAN. Therefore, the faster CAN FD should be introduced.

Secondly, in terms of bandwidth, CAN FD can better meet the demand. As the functions continue to increase, the load of the CAN bus will gradually reach its limit, resulting in increased delay time and insufficient network bandwidth (poor network transmission capacity). In this case, the method of dividing local networks according to functions can solve the problem of insufficient bandwidth. The maximum transmission rate of CAN can reach 1Mbps, and CAN FD can reach 8Mbps. If CAN FD is used instead of CAN, there is no need to use the method of dividing local networks to solve the bandwidth problem.

Finally, there is information security. Authentication and integrity protection of sensitive data in vehicle communications are necessary to ensure the security of vehicle communication systems. In the past, vehicle CAN bus communications transmitted unencrypted data. Once hacked by a third party, the vehicle's key data, such as speed, steering, braking, etc., can be directly read. Once illegally used, the consequences are disastrous. In CAN FD, encrypted data transmission of multiple nodes can be achieved with almost no effort.

TI 's system basis chip with integrated CAN FD controller and transceiver

TI recently launched the industry's new automotive system basis chip (SBC) TCAN4550-Q1. The chip integrates a controller and transceiver using a flexible data rate controller area network (CAN FD), designed to meet the needs of in-vehicle networks for high bandwidth and data rate flexibility. It uses the serial peripheral interface (SPI) bus of almost all microcontrollers to deploy the CAN FD interface or increase the number of CAN FD bus ports in the system, while making minimal changes to the hardware.

TCAN4550-Q1 Functional Block Diagram

In the past, when upgrading to or expanding CAN FD functionality, designers had to integrate multiple discrete components into their designs or completely modify the microcontroller, which is usually time-consuming and costly. With the TCAN4550-Q1 system basis chip (SBC), designers can retain their existing microcontroller-based architecture for automotive electronics and lighting, advanced driver assistance systems (ADAS) and automotive gateway designs, simplifying the upgrade or expansion of CAN FD.

Click here to view reference designs using the TCAN4550-Q1, including:

Short Range Radar (SRR) Reference Design

Automotive RFCMOS 77GHz radar module reference design with target data output via dual CAN FD

Automotive Standalone Gateway Reference Design with Ethernet and CAN