By Richard Solomon, PCI-SIG Vice President

Before the emergence of autonomous driving, our cars provided isolation from the outside world. We could move from point A to point B with the press of a pedal and a Mapquest print-out in the passenger seat. Now, with the plethora of modern methods for connecting with others, we’re bringing the outside world into our vehicles and maintaining those digital connections while on the road.

According to a 2020 report from Frost & Sullivan, “the global autonomous car and EV test and measurement market is estimated to generate revenues of $1.6 billion by 2025. Among four types of testing—advanced driver-assistance systems (ADAS), EV, infotainment, and connected car—ADAS is estimated to have the highest growth, reaching $659.9 million by 2025. This expansion can be attributed to the number of electronic control units (ECUs) and domain control units (DCUs) that are incorporated into a vehicle to make it fully autonomous and reduce its production time.” That’s a lot of new chip designs and a lot of money! Many aspects of technology have played an essential role in the growth of connected cars over the years. Recently, the incorporation of data integration and Machine Learning (ML) has unlocked this significant market growth as automobiles now require compute power that used to be solely the domain of supercomputers. Fortunately, the same PCIe technology that meets these bandwidth and reliability demands in traditional High Performance Computing (HPC) is being deployed throughout the automotive industry.

PCI Express® (PCIe®) Specifications in Cars Today

Advanced Driver Assistance Systems (ADAS) and infotainment systems are quickly becoming the automobile norm, rather than an expensive additional feature limited to high-end autonomous cars. The adoption of the PCIe architecture is expanding rapidly from its start inside infotainment systems to providing reliable high bandwidth links between the processing units for ADAS. PCIe technology is also quickly becoming the standard interface for radio modules housing the 4G/5G connectivity subsystem. Due to the success behind the deployment of PCIe specifications in other markets like Artificial Intelligence (AI) and ML, it is only natural to adopt PCIe technology in automotive as cars become high-tech “servers on wheels.” PCIe technology is the interconnect of choice within advanced vehicles for three primary reasons: bandwidth, connectivity and the breadth of the PCI Express technology ecosystem.

Bandwidth

The PCI Express specification roadmap has documented PCI-SIG’s history of doubling the bandwidth of previous specifications for five generations now, with the release of the finalized PCIe 6.0 specification on the horizon for 2021. The use of PCIe architecture in these advanced systems is the practical and future-looking option, with PCIe 4.0 specification reaching 16 GT/s, PCIe 5.0 specification delivering 32 GT/s and PCIe 6.0 specification, which will reach 64GT/s. As the demand for bandwidth increases, developers need technology that supports high bandwidth applications. The progression of the PCIe architecture and PCI-SIG’s dedication to continuing this forward trajectory will enable future specifications to accelerate emerging automotive technologies for years to come.

Connectivity

PCIe technology is a reliable transport mechanism. The hardware guarantees that transferred application packets will arrive at the intended destination. Other options that could be used in a vehicle are not necessarily guaranteed reliable at the hardware level. As a result, software must incur the overhead needed to ensure that all application data arrives at the destination in the proper sequence. Further, PCIe specifications have much lower latency capabilities than other potential solutions derived from traditional networking such as Ethernet. Ethernet was designed for creating networks of desktop and rack-mount computers fanning out to thousands of devices. Ethernet’s flexibility and expandability are clearly advantages when creating a traditional network, but in a relatively closed environment like a car, the latency “cost” of that flexibility can be painful. PCIe technology enables large amounts of data to be transferred with the least amount of latency, while adding hardware-managed reliability.

PCIe Technology Ecosystem

PCI Express interconnects are well-established and tap into a vast, reliable ecosystem of off-the-shelf components, IP blocks, debug tools and much more. These interconnects are supported natively by most processors and SSDs (Solid State Drives). Automotive designers early-on recognized the advantages of SSDs with no moving parts over traditional hard drives for reliability, and now with native PCIe SSDs they can reap immense performance benefits as well. The PCIe technology ecosystem includes a huge range of available devices for storage, networking, AI/ML processing, etc. that take advantage of the extraordinary bandwidth, low latency and high performance that PCIe architecture has to offer. This ecosystem is constantly expanding, leveraging new and existing PCI-SIG specifications in unique ways in the automotive industry. 

Connected cars have made great strides leveraging the PCIe architecture to support ADAS and infotainment systems. With the surge of bandwidth demands within autonomous vehicles, the practice of using PCIe technology in the automotive industry is here to stay. PCIe specifications will continue to offer the bandwidth, connectivity and ecosystem required to make advanced automotive systems successful now and into the future thanks to PCI-SIG’s adept ability to adapt to industry needs.

Still curious about how PCI Express specifications are deployed in the automotive industry? Watch my recent video to learn more.