Display Interface Specifications

Since its creation in 2004, the Display Working Group has tracked the numerous developments in mobile device displays. The group has released several specifications designed to enable the evolution of display technology.

Specifications are available to MIPI members only. For more information on joining MIPI, please go to Join MIPI.

 

Display Serial Interface

Overview

The Display Serial Interface Specification defines protocols between a host processor and peripheral
devices using a D-PHY physical interface. The DSI specification builds on existing specifications by adopting pixel formats and command set defined in MIPI Alliance specifications for Display Pixel Interface 2 (DPI-2) and Display Command Set (DCS) 
 

Scope

DSI defines interface protocols formatting link management, signal timing relationships and error handling. This specification refers to D-PHY Specification for electrical specifications. Device usage of auxiliary buses such as I2C or SPI, while not precluded by this specification, are out of scope.

 

Purpose

The DSI specification defines a high-speed serial interface between a peripheral, such as an active-matrix display module, and a host processor in a mobile device. By standardizing this interface, components may be developed that provide higher performance, lower power, less electromagnetic interference and fewer pins than current devices, while maintaining compatibility across products from multiple vendors.
 

DSI Introduction

DSI specifies the interface between a host processor and a peripheral such as a display module. It builds on existing MIPI Alliance specifications by adopting pixel formats and command set specified in DPI-2 and DCS standards.

A DSI-compliant interface performs the same functions as interfaces based on Display Bus Interface 2 (DBI-2) combination parallel interface sends pixels or commands to the peripheral, and can read status or pixel information from the peripheral. DSI however serializes all pixel data, commands, and events. The traditional and legacy interfaces convey data and control messages to and from the peripheral on a parallel data bus with additional control signals.
 

From a system or software point of view, the serialization and deserialization operations should be transparent. The most visible, and unavoidable, consequence of transformation to serial data and back to parallel is increased latency for transactions that require a response from the peripheral. For example, reading a pixel from the frame buffer on a display module has a higher latency using DSI than DBI. Another fundamental difference is the host processor’s inability during a read transaction to throttle the rate, or size, of returned data.

 

Display Command Set

Overview

The Display Command Set specification defines a means to control and set display module parameter for devices that adhere to the MIPI specifications for mobile device host processor, and display interfaces.

Scope

Display commands and logical flow are within the scope of this specification. In addition, to support device abstraction, several display architectures are also specified.

Electrical specifications and interface protocols are out of scope for this document.
 

Purpose

Manufacturers who implement the DCS specification reduce the time-to-market and design cost of mobile devices by simplifying the interconnection of products from different manufacturers. Using the DCS standard commands simplifies software driver design and can hasten new feature support such as a larger or modified display.

 

Display Pixel Interface

Overview

The Display Pixel Interface (DPI) defines video formats and signaling for Active-Matrix LCD displays for handheld devices. The interface may be configured with data path of 16, 18 or 24 parallel data bits, and several control signals. This document specifies the interface requirements for both ends (host and display) of the link, including the following attributes:

  • Electrical
  • Timing
  • Pixel formats (mapping of pixel bits to data signals)
  • Command set to control display behaviors
     

Scope

The scope of the DPI document is to specify an electrical and logical interface and the power control signaling between a host system (processor or controller) and an active-matrix (AM) display module. The specification is intended for display modules in mobile devices, with display resolution up to 800x480 pixels. This specification does not apply to passive-matrix display modules. 

Purpose

The Display Pixel Interface specification is used by manufacturers to design products that adhere to MIPI specifications for mobile device processor, camera and display interfaces. Implementing the DPI standard reduces the time-to-market and design cost of mobile devices by simplifying the interconnection of products from different manufacturers. In addition, adding new features such as larger or additional displays to mobile devices is simplified due to the extensible nature of the MIPI specifications.

 

Display Bus Interface v2.0

Overview

This document describes Display Bus Interface (DBI), which is used for display modules. DBI can be configured for 1, 2, 8, 9 or 16 data signals.
This document defines the interface parameters outlined below for both the host processor and display module.
• Electrical
• Timings
• Protocol examples
• Measurement methods
• Color coding
• Command set to control display behaviors
 

Scope

The Display Bus Interface specification defines the electrical and logical interfaces for mobile device host processors and display modules. Logical control of the display module functional blocks such as power supply, timing generator and display drivers is also within the scope of this document. The design of the
functional blocks is not within the scope of this specification.
 

Purpose

The Display Bus Interface specification is used by manufacturers to design products that adhere to MIPI specifications for mobile device processor and display interfaces. Implementing the DBI standard reduces the time-to-market and design cost of mobile devices by simplifying the interconnection of products from different manufacturers. In addition, adding new features such as larger or additional displays to mobile devices is simplified due to the extensible nature of the MIPI specifications.

 

Display Bus Interface-Legacy

Introduction 

This document describes the original version of the Display Bus Interface (DBI), similar to DBI-2. Refer to the above description for a summary of DBI. The MIPI Alliance does not recommend this specification for new designs.

  

Display Pixel Interface - Legacy

Introduction

This document describes the original version of Display Pixel Interface (DPI), similar to DPI-2. Refer to the above description for a summary of DPI. The MIPI Alliance does not recommend the specification for new designs.

 

 

Stereoscopic Display Formats - Active

Overview

This document defines methods to transmit stereoscopic image data between a mobile device host

processor and a display peripheral usually over a high-speed serial link. The nature of mobile devices and how these devices are used lead to various parameters and design options available for a stereoscopic display defined within this specification.
 

Scope

This document details how stereoscopic display options can be implemented using a simple controlfunction. It provides examples of how stereoscopic images are mapped from the host processor over a serial link to the display peripheral, the order of pixel data and orientation of the stereoscopic image. Technical data not within the scope of this document include, color order within pixel data, the commands for image manipulation and control, and mechanisms for controlling the serial link. The reader should refer to other relevant documents.

 

Purpose

The DSI specification defines a high-speed serial interface between a peripheral, such as an active-matrix display module, and a host processor in a mobile device. By standardizing this interface, components may be developed that provide higher performance, lower power, less electromagnetic interference and fewer pins than current devices, while maintaining compatibility across products from multiple vendors.