MIPI A-PHY Compliance Program Advances After Successful Pilot Phase

The MIPI A-PHY Compliance Program is now officially moving forward, following a board review in late June of the program's successful pilot phase, which included two test events with participation from multiple member companies. When the program is fully implemented, automotive original equipment manufacturers (OEMs) and system designers will be able to validate that MIPI A-PHY^® devices have been tested and deemed compliant with the specification.

Typically, MIPI develops conformance test suites (CTSs) for protocol and PHY specifications that can be used to measure conformance to the specification. The A-PHY Compliance Program will go further by not only standardizing the methods of implementation (MOIs), but also by approving authorized test labs and publishing an official list of compliant devices.

Addressing a Particular Need in the Automotive Market

Compliance programs have tremendous benefit for the automotive industry due to a variety of challenges, including "box-to-box" complexities in distance and vehicle design, the industry’s exacting requirements around functional safety (FuSa), and the particularly challenging design environment in terms of electromagnetic interference (EMI). Multiple vendors often supply the various electronic control units (ECUs) and components used for advanced driver assistance systems (ADAS), autonomous driving systems (ADS) and other surround-sensor applications, and interoperability can be tested only at a late stage in a vehicle’s design lifecycle. Because of this, compliance programs increase the chances of success, while significantly reducing development time and cost.

Further, since A-PHY is the first industry-standard asymmetric SerDes physical layer interface to be introduced for these applications, the A-PHY Compliance Program offers a crucial mark of assurance for integrators of the new specification.

Phased Approach to Implementation

The compliance program, which is being coordinated by BitifEye Digital Test Solutions GmbH in partnership with Resillion (formerly Eurofins Digital Testing), is now amid the first of four planned phases of development that are expected to roll out over the next couple of years. The foundation of the program is the series of tests outlined in the current draft version of the A-PHY Reference Compliance Test Suite. These tests are also being evaluated as part of the program's development.

The A-PHY Working Group’s focus areas for Phase I include formalization of TX testing, initial RX and protocol testing, and formalization of MOI documentation.

Ultimately, the compliance program will encompass full coverage of the A-PHY specification, with later phases extending to the many A-PHY protocol adaptation layer (PAL^℠) specifications, which enable higher-layer protocols to operate seamlessly over the MIPI A-PHY physical link. PAL testing will likely begin with those for camera (MIPI CSI-2^®) and then include others in the portfolio, such as those for I2C and GPIO.

Supporting Test Events

The MIPI A-PHY Compliance Program will hold its next test event at a Resillion (formerly Eurofins) laboratory in Hasselt, Belgium. Setup and preparation are scheduled for 17 December 2023, with testing to take place 18 and 19 December. The A-PHY Working Group welcomes participation from any silicon implementer or system vendor, as well as additional test equipment vendors.

This will be the third event in the program to date. A first pilot-phase test event was completed in conjunction with MIPI's Vancouver member meeting in October 2022, which was followed by a more extensive testing event hosted by Resillion (formerly Eurofins) that took place 11 May 2023. Companies participating in the events included BitifEye Digital Test Solutions GmbH and Resillion providing event coordination, Keysight Technologies Inc. and Tektronix Inc. conducting tests, and Valens Semiconductor providing devices under test (DUTs). 

At the Belgium event this month, DUTs will be evaluated in actual lab conditions against a greater portion of the A-PHY Reference Compliance Test Suite than in previous pilot events. Insights gained from those earlier events will continue to be implemented and allow for the correlation of results from multiple vendors. 

Getting Involved

For more information about the MIPI A-PHY Compliance Program, please contact George Goodman, A-PHY Working Group technical program manager. For more information about the 17-19 December test event, please contact Tom Kopf, chief operating officer at BitifEye.