Monday, October 11, 2021

MIPI Alliance doubles performance of automotive SerDes to 32 Gbps

The MIPI Alliance completed development work on A-PHY v1.1, the next version of the automotive serializer-deserializer (SerDes) physical-layer interface. 

Version 1.1 will double the maximum available downlink data rate from 16 Gbps to 32 Gbps and include other enhancements to help automotive OEMs and their suppliers implement high-performance image sensors and displays in next-generation vehicles. The specification is undergoing member review, with official adoption expected within the next 90 days.

"A-PHY continues to evolve to meet the ever-increasing demand for high-performance, end-to-end automotive connectivity solutions with high reliability, resiliency and interoperability," said Joel Huloux, chairman of MIPI Alliance. "With unprecedented bandwidth and a growing number of implementation options, A-PHY is positioned to power the development of the next generation of safer, more connected and autonomous vehicles."

MIPI A-PHY is the first industry-standard, long-reach, asymmetric SerDes interface to provide high-performance links between automotive image sensors and displays and their associated electronic control units (ECUs). It was developed to simplify the integration of greater numbers of onboard sensors and displays for applications such as advanced driver-assistance systems (ADAS), digital cockpits, in-vehicle infotainment (IVI) and autonomous driving systems (ADS).

  • A-PHY offers a reach of up to 15 meters, unprecedented reliability with an ultra-low packet error rate of 10-19, high noise immunity and ultra-low latency. It also forms the foundation of MIPI Automotive SerDes Solutions (MASS), an end-to-end framework for connecting cameras, sensors and displays with built-in functional safety, security and data protection.
  • A-PHY v1.1 doubles the total downlink data rate from 16 to 32 Gbps by adding support for Star Quad (STQ) shielded dual differential pair cables that provide dual differential pairs of conductors within a single shielded jacket. This enables two A-PHY ports over a single cable, saving cost, weight and complexity compared with using two separate coaxial or shielded twisted pair cables.
  • Version 1.1 will also add optional PAM4 encoding for A-PHY downlink gears G1 and G2, with data rates of 2 Gbps and 4 Gbps, respectively. PAM4 encoding features lower modulation bandwidth for sub-1 GHz operation, allowing manufacturers to more easily migrate to A-PHY while using either legacy cables on current platforms or lower-cost cables on new platforms.
  • The new version will also add a faster uplink gear with an available data rate of up to 200 Mbps, twice the rate of the existing 100 Mbps uplink gear, providing more bandwidth for command and control of automotive peripherals. A-PHY v1.1 will be fully interoperable with A-PHY v1.0, and devices using both specifications will be able to coexist on the same network.