P2977 - Adoption of MIPI Alliance Specification for A-PHY Interface (A-PHY) Version 1.0
Project Details
The standard provides an asymmetric data link in a point-to-point or daisy-chain topology, with high-speed unidirectional data, embedded bidirectional control data and optional power delivery over a single cable. In this way, it reduces wiring, cost and weight, as high-speed data, control data and optional power share the same physical wiring. For integration with existing network backbones, it complements Ethernet, Controller Area Network (CAN), FlexRay and other interfaces. Features of A-PHY v1.0 include: • Ultra-low packet error rate (PER) of 10-19 over the vehicle lifetime • Ultra-high immunity to Electro Magnetic Compatibility (EMC) effects in demanding automotive conditions • A reach of up to 15 m • Data rate as high as 16 Gb/s with a roadmap to 48 Gb/s and beyond A-PHY v1.0 is available in two profiles and five gears to meet the various performance, cost and complexity requirements of different applications. It will also support coaxial cables and shielded differential pair (SDP) cables, each with up to four inline connectors. A-PHY also includes several functional safety provisions, such as cyclic redundancy checks (CRCs) in both the packet header and footer, an 8-bit message counter in the header to defend against replay attacks, and a timeout monitor to detect loss of communication. It also offers a time-bounded PHY-level local retransmission scheme (RTS) to recover damaged A-Packets for a steady connection. A-PHY connects to upper-layer protocols through standardized protocol adaptation layers (PALs) that convert upper-layer protocol data into an A-Packet format. PALs are being developed for MIPI CSI-2 and DSI-2, several low-speed control protocols (including General Purpose Input/Output (GPIO), Inter-Integrated Circuit (I2C), Inter-IC Sound (I2S) and others) and third-party protocols such as VESA Embedded DisplayPort / DisplayPort (eDP/DP). A-PHY allows connectivity through its adaptation layers to upper protocol layers that allow end-to-end security and functional safety protections. In addition to automotive uses, the specification is well-suited for IoT and industrial applications that require a longer reach and high immunity to EMI effects.
Standards Committee
PAR Approval
Working Group Details
Working Group
Standards Committee
IEEE Program Manager