MIPI I3C is a bus interface for connecting sensors to an application processor. It is a core sensor integration technology that can combine multiple sensors from different vendors in a device to streamline integration and improve cost efficiencies. It gives developers unprecedented opportunity to craft innovative designs for any mobile product, from smartphones, to wearables, to safety systems in automobiles.
MIPI I3C can integrate mechanical, motion, biometric and environmental, and any other type of sensor. It incorporates key attributes of the traditional I2C and SPI interfaces to provide a new, unified, high-performing, very low power solution. The technology is implemented on a standard CMOS I/O. It uses a two-wire interface, which reduces pin count and signal paths to offer system designers less complexity and more flexibility. It can also be used as a sideband interface to further reduce pin count. MIPI I3C supports a minimum data rate of 10 Mbps with options for higher performance high data rate modes, offering a substantial leap in performance and power efficiency compared with previous options.
Additional technical highlights include multi-master support, dynamic addressing, command-code compatibility, and a uniform approach for advanced power management features, such as sleep mode. It provides synchronous and asynchronous time-stamping to improve the accuracy of applications that use signals from various sensors over time. It can also batch and transmit data quickly to minimize energy consumption of the host processor.
MIPI I3C is developed by the MIPI Alliance Sensor Working Group.
Sadly, it seems you have to shell-out $$$ in membership fees to see the actual spec.
Whitepaper via EE Times (requires login)
Update: Whitepapaer direct from MIPI - no login required