Connect existing upper-layer protocols over MIPI A-PHY interface for long-reach SerDes connectivity solutions

Quick Facts

Key Highlights
  • Define flows and mechanisms for higher-layer MIPI and approved third-party protocols to be carried across MIPI A-PHY
  • Allow automotive designers to leverage existing de facto higher-layer protocols for connecting in-vehicle cameras, displays and other components.
  • Part of MIPI Automotive SerDes Solutions (MASS) that support advanced driver assistance systems (ADAS), autonomous driving systems (ADS), in-vehicle infotainment (IVI) and other surround-sensor applications
  • Simplify in-vehicle networks and reduce costs and development time for automotive original equipment manufacturers (OEMs) and system integrators
  • Allow integration of future protocol innovations using a standardized connectivity framework
Fundamental Features
  • Map higher-layer protocols to MIPI A-PHY’s A-Packet format for transmission and reception over long reach A-PHY SerDes interfaces
  • Robust family of MIPI PAL specifications developed for most common in-vehicle protocols
  • Help enable end-to-end interoperable SerDes solutions
Use Cases
  • Advanced driver assistance systems (ADAS)
  • Autonomous driving systems (ADS)
  • In-vehicle infotainment (IVI)


Icon of an Automobile


MIPI Protocol Adaptation Layer (PAL) specifications define the flows and mechanisms for various widely adopted higher-layer protocols to be carried across the MIPI A-PHY® long-reach serializer-deserializer (SerDes) physical layer interface for automotive applications. MIPI PALs define the adaptations necessary to carry proven MIPI and approved third-party protocols over a MIPI A-PHY link to connect cameras and displays to their associated electronic control units (ECUs). The MIPI PALs map those approved higher-layer protocols to MIPI A-PHY's A-Packet format, acting as a conduit to and from A-PHY’s generic data link layer. In this way, the PALs enable the higher-layer protocols to operate seamlessly over MIPI A-PHY physical links.

MIPI Protocol Adaptation Layers

MIPI has developed multiple PAL specifications to simplify the integration of A-PHY to a variety of upper-layer protocols. PALs are now available for I²C (Inter-Integrated Circuit), GPIO (General Purpose Input/Output), MIPI Camera Serial Interface (CSI-2®), and MIPI Display Serial Interface (DSI-2℠), as well as the Video Electronics Standards Association (VESA®) Embedded DisplayPort and DisplayPort™ standards. In addition, a PAL for carrying up to 100Mbps Ethernet traffic over an A-PHY v1.1 network for command and control of peripherals was released in 2022.


MIPI Protocol Adaptation Layers:

  • MIPI PAL℠/GPIO (January 2021)
  • MIPI PAL℠/I²C (January 2021)
  • MIPI PAL℠/CSI-2® (April 2021)
  • MIPI PAL℠/DSI-2℠ (April 2021)
  • MIPI PAL℠/eDP-DP (April 2021)
  • MIPI PAL℠/ETH (March 2022)
  • MIPI PAL℠/I3C® (under development)
  • MIPI PAL℠/SPI (under development)

MIPI PALs are available to MIPI Alliance members. For information about becoming a member, see Join MIPI.

Get the Specification

MIPI PAL℠/CSI-2®  Member version

MIPI PAL℠/DSI-2℠  Member version

MIPI PAL℠/eDP-DP  Member version

MIPI PAL℠/ETH  Member version

MIPI PAL℠/GPIO  Member version

MIPI PAL℠/I2C  Member version