MIPI I3C TCRI℠

• Fundamental Features

  • Publicly available to developers and the open source community
  • Simplifies MIPI I3C and MIPI I3C Basic bus implementation
  • Renders software reusable across applications

• Current Version

  MIPI I3C TCRI^℠ v1.0 (September 2022)
  Member version  | Public version 

• Related Specifications

  MIPI I3C^®/MIPI I3C Basic^℠

  MIPI I3C HCI^℠

General Info

• Overview

  MIPI I3C Transfer Command Response Interface (MIPI I3C TCRI℠) defines standard transfer command and transfer response structures that MIPI I3C® and MIPI I3C Basic℠ implementations can use as part of an interface in smartphones, computers, Internet of Things (IoT) devices, automotive systems and other applications that leverage the scalable, low-power, medium-speed, two-wire I3C/I3C Basic utility and control bus interface.

  MIPI I3C TCRI enables developers and integrators to easily reuse specific portions of normative definitions for transfer command and response in the existing MIPI I3C Host Controller Interface (MIPI I3C HCI℠) specification. In this way, I3C TCRI delivers a leap forward in simplicity and efficiency of I3C/I3C Basic deployment, rendering software more easily reusable across diverse implementations.

  MIPI Alliance welcomes contributions to the specification. If you would like to contribute, please contact the MIPI Software Working Group at software@mipi.org.

• Key Features

  System designers can point to MIPI I3C TCRI as a standard definition of commands and responses flowing in two directions, without concern about application-specific details such as registers. I3C TCRI standardizes initiation of I3C/I3C Basic writes and reads, as well as behavioral requirements for an I3C controller for processing I3C transfers in sequences, and abstracts the basic functions of transfer command and response behaviors, data structures and flow requirements. By leveraging I3C TCRI, system designers do not have to change the top layer of the software stack from application to application, whether I3C/I3C Basic is deployed in a local system with an I3C HCI-compliant controller, or over MIPI A-PHY, Ethernet or some other bus. 

• How TCRI Fits into the I3C Ecosystem

  MIPI I3C TCRI v1.0 was released in September 2022.
  
  Originally introduced in 2016, MIPI I3C is a scalable utility and control bus interface, providing a unified, high-performing, very-low-power solution for connecting peripherals to a processor. The interface gives developers unprecedented opportunities to craft innovative designs for any mobile product—from smartphones, to wearables, to systems in automobiles. Bundling the features most commonly needed by developers and other standards organizations, MIPI I3C Basic is a publicly available subset of the full I3C specification. 
  
  Upon its release in 2018, MIPI I3C HCI delivered breakthrough efficiencies for designers of applications leveraging I3C and I3C Basic by providing a consistent method for interfacing operating systems to I3C or I3C Basic, and eliminating the need for product-specific drivers. The generic, portable I3C/I3C Basic drivers that I3C HCI enables convey greater control over ongoing development costs and complexity.
  
  MIPI I3C TCRI splits the I3C HCI transfer command and transfer response structures into their own specification. I3C TCRI can serve as the starting point for any network integrations that encapsulate I3C/I3C Basic.