A high-speed, bidirectional protocol primarily intended for image and video transmission between cameras and hosts within a multi-layered, peer-to-peer, UniPro-based M-PHY device network
Networking over UniPro
UniPro + M-PHY
MIPI CSI-3SM is a camera subsystem interface that can be used to integrate digital still cameras, high-resolution and high-frame-rate sensors, teleconferencing and camcorder functionalities on a UniPro network.
MIPI CSI-3 is developed by the MIPI Camera Working Group.
The specification is available as v1.1 and defines the MIPI camera application layer for the MIPI UniPro v1.6 multi-layer network stack whose physical layer is, in turn, defined by the MIPI M-PHY v3.0 specification. CSI-3 and UniPro collectively support high image data transfer rates, fast bidirectional in-band camera control, device discovery capabilities, data delivery with acknowledgement, and management of multiple data streams using virtual channels.
The MIPI M-PHY physical layer supports bidirectional transfers using a pair of unidirectional serial links, and depending on speed, provides up to six predefined and high-speed serial transfer rates (or fixed gears) in either the forward or reverse direction. Each two-wire lane within each link in either direction also has its own embedded clock implemented using 8B10B line coding.
A basic CSI-3 v1.1 link configuration using four forward lanes and one reverse lane (10 total wires) can support up to 14.88 Gbps (usable bit rate, including 8B10B and UniPro overhead) in the forward direction and typically supports 1 Mbps or more in the reverse direction. The UniPro stack itself uses some link bandwidth (primarily in the reverse direction) for the purpose of guaranteeing reliable packet delivery to the receiver. Cameras implementing a minimal MIPI CSI-3 configuration consisting of one forward and one reverse lane (four total wires) can transmit 12 BPP 4K video at about 40 FPS.
Note: The full specification is available only to MIPI Alliance members. For information about joining MIPI Alliance, visit Join MIPI.