可重构处理器（Reconfigurable processors）已越来越多地出现在不断快速更新变化的车载信息娱乐系统上。如今，这一技术正欲继续拓展，进军高级驾驶辅助系统（ADAS）领域。而随着自动驾驶技术的出现，现场可编程门阵列（FPGA）及其他定制化处理器也将取得进一步发展。毕竟，在人工智能发展变幻莫测的当下，定制化服务已变得日益重要。

如今，越来越多的整车厂（OEM）开始将软件性能作为衡量车辆性能的标杆。因此，那些能够帮助汽车硬件作出及时调整，以适应系统算法及车载软件变化的设备，将变得更具实用性。对越来越多的系统来说，软件的升级可以带来性能的大幅提升，而有时仅仅通过调整程序架构，就能使硬件性能更上一层楼。

“算法一直在不断推陈出新，然而研发人员发现，只有在硬件改变的前提下，汽车的性能才能提升2%，但是如果硬件不变的话，这就是空谈。”铿腾（Cadence）旗下Tensilica市场部的集团高级总监Steve Roddy谈到，“研发人员需要一个可编程的解决方案，且该方案的计算力要足够强大。”

在介绍2018款奥迪A8的zFAS自动驾驶技术时，奥迪就着重强调了可重构硬件的重要作用，并再次明确了电子控制技术对程序计算有着非常高的要求，因为在关键时刻，这将是攸关生死的问题。英特尔（Intel）全新的Cyclone V FPGA将搭载ARM双核处理器，可以有效提升奥迪控制单元的性能。其他一同搭载的重要部件还包括英伟达（Nvidia）的图形处理器、Mobileye的视觉处理器以及中央处理器等。

“在这款奥迪车上，我们首次将异质性方式运用到ADAS系统上。”英特尔汽车驾驶编程方案集团（Intel’s Automotive Programable Solutions Group）高级总监Michael Hendricks告诉我们，“ADAS和自动驾驶的发展可谓突飞猛进，几乎每三个月就会有一项重大突破。专用集成电路（ASIC）的研发者很难迅速抓住应用的要点，而FPGA则带来了很多帮助，研发者也能更从容灵活地去适应这些变化。”

这一技术巨大的发展潜力，正吸引着越来越多的FPGA供应商，Xilinx就是其中之一。借助可重构设备，设计团队改动处于研发阶段后期的硬件时可以更省力。与此同时，设计人员也可借此设置控制单元，以适应不同模型的需求。比如，有些ADAS系统会比同类产品多几个感应器。

“有了FPGA，就能更好调整I/O（输入/输出），正确设置LVDS（低电压拆分信号）和CAN连接。”Hendricks指出，“比如说，FPGA可以提供海量的逻辑门，因此，可以对硬件与软件进行编程，从而优化算法与硬件。”

定制化的硬件过去主要是用于研发的，而ASIC和专用处理器则投入量产。然而，在车载多媒体逐步取代无线收音设备后，定制化硬件的功能也随之突破了自身局限。如今，随着用户对于娱乐资讯软件的特性和功能提出了更多的要求，这些硬件能派上用场的地方也越来越多。在大型车辆内，定制化的处理器甚至可用来支持人与人之间的沟通交流。

“在大型SUV中，汽车顶棚的智能声音接收系统能够识别谁在说话，并将其声音通过扬声器播放出来。”Roddy说道，“这些芯片可以实现很多此类功能。”

目前，由于用户对于汽车安全性和车载多媒体需求的不断增加，汽车IC市场有着长期稳定的增长预期。据IHS Markit预测，汽车半导体的市场总规模将会从2016年的321亿美元上升到2017年的344亿美元，较2015至2016年7%的增长水平略有提升。

长期的增长预期，也在不断推动着汽车芯片市场的变革。英特尔收购了生产FPGA的阿尔特拉（Altera），又收购了制造视觉处理器的Mobileye。高通（Qualcomm）则在积极收购恩智浦半导体（NXP Semiconductors），而恩智浦去年刚刚合并了飞思卡尔半导体（Freescale Semiconductors）。据花旗集团（Citigroup）估算，英伟达（Nvidia）——这个原本并未大举进入汽车行业的公司，将会在2018会计年度在汽车这块注资10亿美元，想必也和2017会计年度该领域收益上升52%不无关联。

尽管像英伟达和铿腾（Cadence）这样的业界新贵已开始专注汽车应用软件，传统供应商依旧延续了其市场龙头的地位。Semicast Research的数据显示，2016年，恩智浦、英飞凌（Infineon）、瑞萨（Renesas）、意法半导体（ST Microelectronics）和德州仪器（Texas Instruments）依旧是全球最大的几家自动驾驶组件供应商。而在位列前十的全球顶尖自动驾驶技术公司中，还有博世（Robert Bosch）、On Semiconductor、微芯科技（Microchip Technology）、东芝（Toshiba）和罗姆半导体（Rohm Semiconductor）等。

Reconfigurable processors have seen growing use in rapidly-changing infotainment systems and are expanding into advanced driver assistance systems (ADAS). The role of field-programmable gate arrays (FPGAs) and other customizable processors is expected to develop further with the emergence of autonomy, where the vagaries of artificial intelligence makes customization more important.

As vehicle OEMs make software more of a differentiator, devices that make it simple to alter hardware to match changes in algorithms and software are becoming more practical. In a growing number of systems, changes in software can improve performance significantly. Sometimes, performance can be further improved by altering the programming structure.

“Algorithms change rapidly, researchers can find 2% better performance, but they can’t do that if they can’t change the hardware,” said Steve Roddy, Senior Group Director, Tensilica Marketing at Cadence. “They need a programmable solution that has the computing horsepower they need.”

The 2018 Audi A8’s zFAS piloted driving highlights the growing role of reconfigurable hardware, as well as the demanding computing requirements of electronic controls that make life or death driving decisions. An Intel Cyclone V FPGA that has dual ARM cores augments Audi’s control module, which also employs an Nvidia GPU, a Mobileye vision processor and a basic CPU.

“Audi is our first adoption in an ADAS system with a heterogenous approach,” said Michael Hendricks, Senior Director of Intel’s Automotive Programable Solutions Group. “ADAS and autonomy are moving so rapidly, there’s a major breakthrough every three months. It’s difficult for an ASIC developer to hit the bulls eye. FPGAs bring a lot of assets and give developers more flexibility to adapt.”

Expectations of strong growth is attracting other FPGA suppliers like Xilinx. Reconfigurable devices make it simpler for design teams to alter hardware late in development cycles while also letting them configure control modules that can be used in various models. For example, some ADAS systems may have more sensors than others.

“With an FPGA, you can tailor the I/O, setting the right number of LVDS and CAN connections, for example,” Hendricks noted. “FPGAs offer a sea of logic gates so both hardware and software can be programmed so algorithms and hardware are optimized.”

Customizable hardware was once used primarily for development, with ASICs or specialized processors used in production. But that limitation faded as radios transformed into infotainment systems. These devices are seeing more widespread usage in infotainment as users demand more features and functions. In large vehicles, customized processors will help foster communications between humans.

“In a big SUV, smart microphones in the headliner can figure out who’s talking and send their voice through the speakers,” Roddy said. “These chips let them layer in this level of functionality.”

Safety and infotainment are primary drivers behind expectations of continued solid growth for automotive ICs. IHS Markit expects the automotive semiconductor market from $32.1 billion in 2016 to $34.4 billion in 2017, slightly outpacing 7% growth from 2015 to 2016.

Long-term expectations are fueling major changes in the automotive chip world. Intel acquired Altera, which makes FPGAs. It also acquired Mobileye, maker of vision processors. Qualcomm is in the process of acquiring NXP Semiconductors, which last year purchased Freescale Semiconductors. Citigroup predicts that Nvidia, once a small player in vehicles, will hit $1 billion in automotive in fiscal 2018 after seeing revenue rise 52% in fiscal 2017.

Though newer companies like Nvidia and Cadence are focusing on automotive applications, traditional suppliers have maintained the bulk of the market. NXP, Infineon, Renesas, STMicroelectronics and Texas Instruments were the largest automotive suppliers in 2016, according to Semicast Research. Robert Bosch, On Semiconductor, Microchip Technology, Toshiba and Rohm Semiconductor rounded out the top 10.

Author: Terry Costlow
Source: SAE Automotive Engineering Magazine