Automotive displays: Infotainment demand generates show-stoppers
Displays are evolving to meet the requirements of intelligent networks for personalised connected vehicles, writes Claus Giebert.
Where once in-vehicle infotainment amounted to little more than car radio and CD players, today it has evolved into navigation systems, video players and network connectivity hubs.
Emerging trends such as in‑car Wi‑Fi, driver personalisation, car sharing and corporate fleet management are increasing the demands on designers. Advanced driver assistance is another trend where automotive OEMs are keen to enhance safety technology and curtail errors until fully autonomous transport arrives.
All of these advances are just the tip of the iceberg. By leveraging artificial intelligence (AI) and the IoT, cars are essentially becoming a bigger version of a smartphone, complete with in‑vehicle personal assistants. V2X (vehicle‑to‑everything) technology is rapidly becoming a reality. This trend includes car-to-home automation, where drivers can turn on the lights at home, as well as the heating or air conditioning systems – all from an icon on the car’s graphical display.
According to ‘Global Automotive Infotainment SOC Market Growth 2020-2025’ published by Market Study Report, the global automotive infotainment SoC market was worth $7.25bn in 2019 and was expected to grow at a CAGR of 7.8% through to 2025, by which time it would be worth $9.78bn.
Importantly, this estimate took into account the impact of Covid-19. So despite the effects of a global pandemic, the latest SoC advances are likely to continue accelerating the development of in-vehicle graphical display and infotainment applications, moving automotive manufacturers closer to the advent of fully connected vehicles.
Such SoC technology is making it easier for design engineers to develop automotive applications, even for those who are not accustomed to leveraging the benefits of embedded solutions.
For developers looking to create in-seat infotainment systems, then SoC selection needs to be carefully considered.
The first decision is processor choice: x86 or Arm based SoCs? The latter are favoured in mobile applications where better power efficiency is advantageous, or where there is a need to support the Linux or Android tool chain.
The next choice is module form factor. For example, SMARC is an agnostic low power embedded architecture platform for SoCs, including those based on x86 and Arm technology. The form factor allows developers to create mobile, embedded, connected solutions using a scalable building-block framework.
Other advantages include optimised pin-out definition for versatile architectures, low profile solutions and the ability to withstand harsh environments. In addition, the CPU‑ and supplier-agnostic SMARC standard offers customers security against commercial, production and technical issues created by proprietary single source solutions.
Typically NXP’s i.MX 8M processors are better at video encoding and decoding, which helps considerably for bi‑directional video communication applications. They also support a variety of software and operating systems.
For example, Advantech offers an i.MX 8M SMARC 2.0 module, initially supporting the open source Yocto, which helps developers create custom Linux‑based systems regardless of hardware architecture. It is supports Android 8.0 and Ubuntu, a Linux distribution based on Debian that mostly comprises free and open source software.
The i.MX 8M is typically used by developers looking to drive one or two displays, or perform video playback or some type of automation but it is not intended for functional safety applications.
As an alternative to an external implementation, manufacturers provide modules which incorporate support for functional safety in the automotive market.
For example, the i.MX 8QuadMax and the i.MX 8X SoCs (see box) use Cortex-A-based CPU clusters for high performance operation and Cortex‑M‑based clusters for power efficiency. The SoCs have been specifically designed for use in intelligent or full graphic car dashboards.
As the complexity of car instrument clusters rises, so the need for fail‑safe mechanisms becomes increasingly important. With this thought in mind, there are a number of vital factors regarding car dashboards that not only relate to graphics, but to certain call‑back and safety requirements.
In the event of a dashboard failure, it is not a disaster if a graphic disappears, but the speed readout must be maintained, or at least recovered quickly. There is a functional requirement from car manufacturers stating that speed and mileage must always remain visible to the driver.
A second display channel, managed by the Cortex‑M4F CPU cluster, allows the system to recover in a minimum period, showing a simplified version of the speedometer until the full graphics system comes up again.
Another option, the i.MX 8QuadXPlus, features four 1.2GHz Cortex-A35 processors, together with hardware accelerators like GPU and video encoders/decoders. Independently from the main Cortex‑A system, the Cortex‑M4F can run in its own cluster, providing real time and safety‑critical functions to the system. A powerful resource domain controller manages the partitioning of the available resources inside the i.MX 8QuadXPlus, to ensure, in hardware, that software clusters can only access their predefined resources.
The i.MX 8QuadMax offers the same features, but with a more powerful CPU system, composed of two Cortex‑A72, four Cortex‑A53 and two Cortex‑M4F micro architectures.
To summarise, the tight system integration of SoCs offers high reliability and extended mean time between failure (MTBF), alongside advanced functionality and high computing power. SoCs offer advantages in terms of price, size and energy efficiency. The level of integration on a single substrate reduces the number of physical chips and solder connections, and reduces wiring.
These traits mean that SoCs are increasingly deployed as automotive‑grade devices for a wide range of infotainment systems, including the latest displays featuring smartphone mirroring and support of rear-view cameras. Here, there is a distinct requirement for multi‑core processors with ‘best-in class’ 3D graphics and video encoding/decoding capabilities.
Using the i.MX 8QuadMax and i.MX 8X family of devices in a safety‑relevant system provides an alternative to conventional designs using a second dedicated external MCU as the safety controller.
Automotive OEMs are responding to market demand and planning the next driver/passenger experiences; ones that can tap into the surge in content brought about by smartphones and cloud connectivity.
Ultimately, SoCs that support real‑time multimedia networks and incorporate the latest interface IP standards and protocols provide the road to successful infotainment application development.
Case study: Moves towards standardisation will improve safety
The i.MX 8X is part of NXP’s SafeAssure programme, designed to simplify system‑level functional safety requirements to build standardisation, sustainability and compliance for functional safety into a design. The programme covers three areas, functional safety, vehicle security and device reliability. The first simplifies the certification process to support development to ISO 26262 and IEC 61508. For vehicle security, a secure vehicle architecture with a 4+1 framework protects the entire vehicle across networked systems and physical protection via secure car access products.
The processors can display safety‑critical information on the instrument cluster, broadcast audible warning tones and show a back‑up camera image even in the event of system failure. The display controllers can detect errors in the display content and switch over to a safety display stream. Software and hardware mechanisms are used to guarantee consistency and correctness of the picture stream coming from a camera. All of this functionality is designed to help developers produce fully certified products that deliver safety and satisfaction.
About The Author
Claus Giebert is business development manager at Advantech