How to Develop an Automotive Gateway for Next-Generation Cars

Subbu Venkat

Automotive Processor Business Development Manager

Texas Instruments

introduce

Automotive architectures are evolving rapidly, with vehicles moving from semi-autonomous driving to eventually fully autonomous driving. Automakers are also adding features such as smart access, vehicle sharing, predictive maintenance, vehicle tracking, fleet management, and over-the-air (OTA) upgrades to enhance connectivity and in-vehicle communications. The increasing amount of data generated by these advanced features requires processing by high-performance processors and secure and reliable communication across interfaces such as CAN, LIN, and high-speed networks such as Ethernet. As a result, automakers are re-evaluating the architecture of automotive gateways and telematic control unit systems (TCUs).

Automotive Gateway

An automotive gateway is a system whose core function is to transfer data securely and reliably within a vehicle. There can be several types of gateways in a vehicle: central gateways and domain gateways (or domain controllers).

The central gateway can securely and reliably transmit data between multiple domains such as TCU, powertrain, body, infotainment system, digital cockpit and ADAS applications.

A domain gateway (or domain controller) has a similar function, except that it only routes data between ECUs within its corresponding domain.

Compared with domain gateways, central gateways usually require stronger processing performance, more interfaces, and higher-bandwidth network protocols.

Figure 1 illustrates how these two types of gateways can be implemented in a vehicle.

TCU

The TCU is the ECU in the vehicle that connects to the Internet and the cloud. Cars connected to the Internet and the cloud are becoming more common as automakers equip their vehicles with Wi-Fi®, Bluetooth®, and cellular data capabilities.

Figure 1. Example SoC architecture with one central gateway and two domain gateways.

This connectivity enables emergency calls (eCall), online access to entertainment and other content while on the move, and over-the-air software updates for digital content in the vehicle.

Emerging trends such as car sharing, replacing key fobs with mobile access, fleet management and tracking, insurance providers remotely monitoring driving habits, and car dealers remotely monitoring vehicle condition to schedule preventative maintenance such as oil changes all require vehicles to be connected to the internet and the cloud.

Another emerging trend that also helps enable fully autonomous vehicles is the ability for vehicles to communicate with other vehicles, infrastructure (such as traffic lights), and even other people. These are referred to as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-pedestrian (V2P). Dedicated short-range communications (DSRC) or c-V2X connections often facilitate this type of communication.

In short, telematics connects cars to the outside world. Figure 2 illustrates telematics.

Figure 2. Telematics example.

Evolving Gateways and TCUs Require Application Processors

Automotive gateway processors are typically 32-bit microcontrollers (MCUs) with built-in memory and common gateway interfaces such as Controller Area Network (CAN), Local Interconnect Network (LIN), and low-speed interfaces such as FlexRay™. However, as cars continue to add ADAS and connectivity features, vehicles must process and communicate more and more data securely and reliably between domains with very low latency.

Since interfaces such as CAN Flexible Data-rate and LIN cannot transfer large amounts of data with low latency, automotive manufacturers are migrating to Ethernet TCP/IP-based protocols to handle higher bandwidth data transfer. TCP/IP is attractive because it is a well-established communication protocol in the consumer space. Therefore, it is less risky than unproven protocols.

MCU itself may not meet the processing requirements of future gateways, so higher-performance application processors are replacing or filling certain MCU functions to process and route data for future gateways. In addition, as in-vehicle networks migrate to Ethernet-based networks, automotive gateways supported by application processors can help process and route data between various domains quickly and efficiently.

Connectivity is required to enable OTA updates of entertainment content and other services such as car-sharing/ride-pooling applications and remote vehicle access. The TCU has a cellular or Wi-Fi® modem to provide connectivity and an application processor to process the data received from the modem. Processing includes decrypting the data, authenticating it, and routing it to the gateway or other domain ECUs. In current architectures, the modem and processor are integrated into a single semiconductor device. However, as modem standards continue to evolve, automakers are moving to architectures that separate the modem from the processor. In addition, both automotive gateways and TCUs are migrating to Ethernet-based networks supported by application processors that have support for high-speed connectivity peripherals such as PCIe and have the computing power to process and route data between domains. The advantage of separating the processor from the modem is that the ECU can be quickly migrated to a new modem standard by replacing only the modem (without changing the processor and all the associated software running on it).

As cars become more connected and autonomous, safety and security are becoming more important in automotive gateways and TCUs. Dedicated embedded security processors or subsystems can help protect access to vehicle security keys, enhance the security of communication channels, and ensure that trusted software updates are not used for cyberattacks. Security functions are often implemented in safety-certified discrete MCUs. System-on-chip (SoC) that integrates an application processor and a security MCU offers automotive OEMs a lower bill of materials (BOM) cost.

Development costs

As mentioned earlier, gateway and TCU systems are becoming increasingly complex in terms of functionality. This results in high development costs for car manufacturers. Ideally, this cost would be avoided by suppliers across all tiers/models of vehicles.

OEMs and Tier 1 suppliers can save development costs with the Jacinto™ DRAx family of automotive processors, which provide a scalable and software-compatible platform to help meet the needs of next-generation gateway and TCU systems. The Jacinto DRA8x automotive processors help enhance connectivity throughout the vehicle by supporting a wide range of high-speed I/Os such as PCIe, USB3.x, Gigabit Ethernet, and traditional automotive peripherals such as CAN-FD and LIN.

These processors are also specifically designed to integrate an on-chip MCU subsystem to help meet the real-time processing needs and performance required by TCUs, application processors and automotive gateways.

The DRA829V is the latest automotive processor in the DRA8X family. The DRA829V is a high-performance SoC that integrates multiple computing and processing cores, making it easier and more efficient for automotive gateways to manage and support higher real-time data throughput. Because this device is equipped with features such as the Arm® Cortex®-A72 MPU cluster and the Arm Cortex-R5F core cluster for real-time processing, as well as high-speed peripherals such as USB-3, integrated PCIe switch, and Gigabit Ethernet switch, higher bandwidth data transmission can be achieved without external components. Another key feature of the DRA829V processor is its integrated functional safety MCU subsystem, which supports ASIL-B to ASIL-D functional safety operations on-chip. The DRA829V processor also includes a full set of traditional automotive peripherals such as CAN-FD, LIN, and MOST. For safety-critical applications, the DRA829 device supports secure boot and runtime environments through an integrated high-security module (HSM). Additionally, the DRA829V processor offers a broad combination of computing power and peripherals to provide a cost-optimized device for a wide range of automotive gateways.

The Jacinto DRA8x processor family includes support for multiple advanced real-time operating systems in the Processor SDK, and it also has a full range of compatible and scalable software development kits (SDKs), allowing OEMs to integrate and reuse design results in their product lines, ultimately reducing development costs. With unified software, automakers can reduce the scale of costly software R&D investments and deploy software for all types of vehicles from entry-level to high-end through their entire central gateway platform.

Innovative next generation gateway system

The architecture of automotive gateways and TCUs is changing rapidly to efficiently process and transfer large amounts of data between various domains in the car. Scalable SoCs with integrated MCU subsystems, application processors, and high-speed I/O capabilities will help meet the needs of this new architecture with a reduced system BOM.

TI's scalable hardware and software-compatible DRA8x SOC family helps meet the needs of new gateway and TCU architectures, helping to reduce system BOM costs and development costs for automotive gateways.