The growing functionality and complexity of recent vehicle electronic systems have made inter-device communication (on-board LAN) technology vital to vehicle design. By field of application, the LAN (Local Area Network) systems currently in use are LIN (Local Interconnect Network) used for body systems, CAN (Controller Area Network) used for control systems, and MOST (Media Oriented Systems Transport ) used for multimedia and camera systems, and work to standardize the next-generation communication technology for each of those fields is underway. This paper provides a technical overview of the CXPI (Clock Extension Peripheral Interface) communication protocol, which satisfies the body system requirements (rapid response, system extensibility, high reliability, and low cost). It also presents the progress made on standardization at SAE and other organizations. The current situation of standardization for CXPI is as follows: JASO standard : May 2014 (1st edition), May 2015 (2nd edition), and May 2016 (final), SAE standard: November 2015 (IR), and ISO standard: May 2015 PWI, May 2016 (NWIP), August 2017 (WD), and August 2019 (IS).