Why can’t mobile phone chips be installed in cars? | Interpretation of car computer chips

Today we are going to talk about the second article in the "Car Chip" series. In the last issue, we discussed why we should upgrade to the 8155 chip and why car chips are so important. So in the second article of our "Car Chip" series, we will take a deeper look at what car chips are and how they differ from mobile phone chips.

What is a car chip?

In layman's terms, "car chip" is a common name for the vehicle cockpit domain controller chip. As its name suggests, the "car chip" is responsible for the coordination of most electronic components in the car, and it is the core of the car's intelligent cockpit. The car chip needs to integrate CPU (central processing unit), GPU (graphics processing unit), DSP (signal processor), NPU (neural network processing unit), as well as memory and various I/O interfaces.

The difference between car chips and mobile phone chips

We know that the 7nm Qualcomm 8155 chip, which has been very popular in recent years, is highly sought after by many car companies. The 8155 is also a revised version of the Qualcomm 855, a consumer-grade mobile phone chip of the same period. So, why are car chips represented by 8155 and mobile phone chips represented by 855 not compatible? What is the difference between them?

Top: Qualcomm 8155 car chip; Bottom: Qualcomm 855 mobile phone chip

The biggest difference between car chips and mobile phone chips is their different uses. As shown in the following figure:

1. Car chips often need to support the simultaneous use of multiple screens and multiple cameras in the car, while mobile phones basically only need to support one screen;

2. Car chips need to meet stricter functional safety and information security requirements than mobile phone chips;

3. Car chips also need to free up more computing power to support assisted driving, such as in-car monitoring, AI face and voice recognition, GPU/NPU/DSP data fusion, and VR navigation. The resulting computing power requirements and allocation are also different from those of mobile phone chips.

And this is only the difference in key technology between the two types of chips. There are more differences in other aspects due to different uses.

Why are car chips more demanding than mobile phone chips?

Since the service life of a car is longer than other consumer electronic products such as mobile phones, the life of a car is generally designed to be around 10 years, so higher requirements are placed on the reliability and safety of components, which is different from mobile phones which are basically replaced every 2-3 years.

In addition, considering the harsh vehicle use environment, the working environment of the car chip is also relatively harsh. For example, the working environment temperature range of the car chip is -40 to 155 degrees Celsius. Therefore, the car chip has very strict requirements in the research and development, production, and manufacturing of the car chip to meet the safety and reliability requirements of the car.

As shown in the figure below, during the testing phase before the two types of chips are put on the market, whether it is the temperature, humidity, high and low temperature durability of the test environment, or mechanical shock, drop testing, etc., the testing standards for car chips are much higher than those for mobile phone chips.

Compared with the "mild" usage environment of mobile phone chips, the harsh environment faced by cars makes the requirements for car chips higher.

Therefore, under the premise of ensuring basic performance requirements, safety and reliability are the most emphasized requirements of car chips. After all, it is okay for a mobile phone to have some problems occasionally, but if the car chip makes a mistake one day and causes chaos on the car's display screen, it can be a matter of life and death.