MIPI releases I3C Basic v1.2 for IoT and mobile devices

The MIPI Alliance has recently unveiled MIPI I3C Basic v1.2, a versatile utility and control bus interface designed to facilitate the connection of peripherals to microcontrollers or application processors, thereby streamlining integration processes and enhancing cost efficiencies. This latest version of the specification introduces a reorganization, featuring distinct sections for mandatory and optional features, allowing designers to selectively implement these features based on specific application requirements.

MIPI I3C Basic represents a subset of the member version of MIPI I3C, which is available under royalty-free terms. Initially introduced in 2016 and subsequently updated to v1.1 in 2019, the I3C interface was developed to build upon the foundational aspects of legacy serial interfaces such as I2C, SPI, and UART, while simplifying implementation processes. Additionally, it offers improved performance and power efficiency, along with a range of features aimed at addressing common challenges encountered by developers.

Furthermore, MIPI I3C Basic has played a pivotal role in various industry collaborations, being adopted by prominent organizations like PCI-SIG, NVM Express, JEDEC, ETSI, and forming the basis of a liaison relationship with DMTF. Its implementation on a standard CMOS I/O utilizing a two-wire interface with in-band interrupts has proven instrumental in reducing pin count and signal paths, thereby offering system designers enhanced flexibility and reduced complexity.

With a typical data rate of 11.1 Mbps and support for high-performance modes reaching up to 100 Mbps, MIPI I3C finds application in diverse scenarios such as connecting peripherals to processors in mobile and embedded devices, system debugging and tracing, and serving as a control sideband bus for DDR5 DRAM memory and SSD control interfaces, as well as the MIPI Camera Control Interface (CCI).

The growing MIPI I3C interface ecosystem encompasses a wide array of products including microcontrollers, microprocessing units, wireless IoT SoCs, sensors, and specialized integrated circuits. A comprehensive suite of tools is available to aid in development and testing, ranging from protocol analyzers and development boards to USB host adapters. Moreover, software drivers compatible with Linux and the Zephyr real-time OS are readily accessible, with companies offering reference implementations tailored to their specific products.

Hezi Saar, chair of MIPI Alliance, expressed optimism regarding the rapid expansion of the MIPI I3C ecosystem, attributing its popularity to the innovative features and substantial enhancements in performance and power efficiency compared to legacy interfaces. The flexibility offered by I3C makes it a versatile choice for a wide range of products, spanning from smartphones and wearables to data center systems. To facilitate seamless integration, MIPI has introduced additional specifications such as Discovery and Configuration (DisCo) for I3C, I3C Host Controller Interface (MIPI I3C HCI), Transfer Command Response Interface (MIPI I3C TCRI), and Debug Over I3C, all of which are publicly available.