MIPI doubles data rate for A-PHY automotive SerDes
The MIPI Alliance has completed development of its next version of its high speed serializer-deserializer (SerDes) physical-layer interface with new encoding to allow it to run over oler cables.
Version 1.1 adds optional PAM4 encoding for A-PHY downlinks with data rates of 2 Gbit/s and 4 Gbit/s. PAM4 encoding features lower modulation bandwidth for sub-1 GHz operation, allowing manufacturers to more easily migrate to A-PHY over legacy cables on current platforms or lower-cost cables on new platforms.
Version 1.1 also doubles the data rate to 32 Gbit/s 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.
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, low packet error rate of 10-19 for reliability, 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.
The new version will also add a faster uplink with an available data rate of up to 200 Mbit/s, twice the rate of the existing 100 Mbit/s 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.
These enhancements will enable automotive manufacturers to design next-generation applications that use the latest camera and display technologies, including higher-performance instrument clusters and infotainment displays, interior driver and passenger monitoring systems, virtual side mirrors and other ADAS, IVI and ADS applications.
“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.”
Upon completion of the MIPI Alliance adoption process, A-PHY v1.1 will also be brought forward for adoption as an IEEE standard. Earlier this year, IEEE adopted A-PHY v1.0 as IEEE 2977-2021.