Camera Serial Interface
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The Camera Serial Interface (CSI) is a specification of the Mobile Industry Processor Interface (MIPI) Alliance. It defines an interface between a camera and a host processor.
The latest active interface specifications are: CSI-2 v4.1 (April 2024), CSI-3 v1.1 (March 2014), and CCS v1.1.1 (April 2023).
Standards
[edit | edit source]CSI-1
[edit | edit source]CSI-1 was the original standard MIPI interface for cameras. It emerged as an architecture to define the interface between a camera and a host processor. Its successors were MIPI CSI-2 and MIPI CSI-3, two standards that are still evolving.
CSI-2
[edit | edit source]The MIPI CSI-2 v1.0 specification was released in 2005. It uses either D-PHY or C-PHY (Both standards are set by the MIPI Alliance) as a physical layer option. The protocol is divided into the following layers: physical, lane merger, low-level protocol, pixel-to-byte conversion, and application.
In April 2017, the CSI-2 v2.0 specification was released. CSI-2 v2.0 brought support for RAW-16 and RAW-20 color depth, increase virtual channels from 4 to 32, Latency Reduction and Transport Efficiency (LRTE), Differential Pulse-Code Modulation (DPCM) compression and scrambling to reduce Power Spectral Density.[1]
In September 2019, the CSI-2 v3.0 specification was released. CSI-2 v3.0 introduced Unified Serial Link (USL), Smart Region of Interest (SROI), End-of-Transmission Short Packet (EoTp) and support for RAW-24 color depth.[2][3]
The most recent version, CSI-2 v4.1, was released in April 2024.[4]
CSI-3
[edit | edit source]MIPI CSI-3 is 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. It was originally released in 2012 and got re-released in version 1.1 in March 2014.[5]
CCS
[edit | edit source]The Camera Command Set (CCS) v1.0 specification was released on November 30, 2017. CCS defines a standard set of functionalities for controlling image sensors using CSI-2.[6][7]
The most recent version, CCS v1.1.1, was released in April 2023.[8]
Technology and speeds
[edit | edit source]For electromagnetic interference reasons the system designer can select between two different clock rates (a and b) in each of the M-PHY speed levels.[9]
| M-PHY speed | Clock rate | Bit rate |
|---|---|---|
| Gear 1 | G1a | 1.25 Gbit/s |
| G1b | 1.49 Gbit/s | |
| Gear 2 | G2a | 2.5 Gbit/s |
| G2b | 2.9 Gbit/s | |
| Gear 3 | G3a | 5 Gbit/s |
| G3b | 5.8 Gbit/s |
See also
[edit | edit source]References
[edit | edit source]- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
