A recent test event marked another milestone in the development of the MIPI A-PHY Compliance Program, as leading test partners convened for a fourth time to perform an in-depth evaluation of A-PHY receiver performance against the requirements defined in the A-PHY Reference Compliance Test Suite (CTS).
Throughout the event, held last month in Böblingen, Germany, participants captured real-world test data and evaluated it against defined pass/fail criteria. This exercise supported iterative refinement of the CTS and the test environments themselves, further solidifying the overall program. Notably, the event reaffirmed A-PHY's exceptional bit error rate (BER) resilience under harsh electromagnetic interference (EMI), far surpassing noise tolerances seen in competing automotive SerDes technologies.
This most recent event builds on the success of the previous December 2024 test event, which validated multiple A-PHY-enabled devices from several vendors, covering both physical-layer transmit and receive paths. Together, these recent events represent a major step forward in validating multi-vendor interoperability and strengthening the technical foundation of the A-PHY Compliance Program.
These events also confirmed the maturity of the A-PHY test infrastructure, paving the way for the upcoming fifth test event scheduled for December 2025, which will expand testing to cover advanced transmitter and receiver test scenarios, introduce protocol-level compliance testing for the first time, and onboard several new participant companies. MIPI members interested in participating in the December event are encouraged to complete the Call for Interest form by 15 September.
The July 2025 event was conducted by BitifEye Digital Test Solutions GmbH, Keysight Technologies Inc., Resillion and Valens Semiconductor. Participants at the December 2024 event included Beijing ESWIN Computing Technology Co., Ltd; BitifEye Digital Test Solutions GmbH; Keysight Technologies Inc.; Protocol Insight, LLC; Resillion; Sony Semiconductor Solutions; Tektronix, Inc.; and Valens Semiconductor.
MIPI A-PHY® is the first industry-standard asymmetric SerDes physical layer interface designed specifically for advanced driver assistance systems (ADAS), autonomous driving systems (ADS) and other high-bandwidth automotive sensor applications -- including cameras, lidar sensors and radars -- as well as in-vehicle infotainment (IVI) displays. A-PHY serves as the physical layer backbone of the MIPI Automotive SerDes Solutions (MASS) framework, providing high-performance, long-reach connectivity while integrating functional safety and security.
The A-PHY Reference Compliance Test Suite (CTS) defines a comprehensive set of tests to validate conformance with "shall" statements in the specification — including EMI limits, link stability at specified data rates and frequencies, and BER thresholds. Successful completion of the test suite ensures an implementation will behave reliably within the defined operating envelope.
The creation of the MIPI A-PHY Compliance Program was initiated in response to strong demand from automotive OEMs and Tier 1 suppliers seeking assurance that A-PHY implementations meet stringent industry expectations. The program is being rolled out in phases, with the initial phase focusing on physical and link layer compliance, based on the current CTS. Future phases will extend coverage to the protocol adaptation layers (PALs), ensuring robust interoperability for higher-layer protocols operating over A-PHY links.
Ultimately, the compliance program is designed to support the automotive industry’s requirements for multi-vendor interoperability, functional safety, EMI robustness, and reduced development time and cost for A-PHY-based systems.
For more information about the MIPI A-PHY Compliance Program, contact George Goodman, technical program manager for the MIPI A-PHY Working Group.