Display Interface Introduction

One, RGB interface

(1) Interface definition

RGB color is a color standard of industry, is through the red (R), Green (G), Blue (B) three color channels and their superposition to get a variety of colors, RGB is the red, green, blue three channels of color, this standard almost includes the human vision All colors that can be sensed are one of the most widely used color systems available.

(2) interface type

A. Parallel RGB

B. Serial RGB

(3) interface features

A. The interface is generally 3.3V level

B. Need to synchronize signals

C. Need to refresh the image data at all times

D. Need to configure the appropriate timing

Parallel RGB Interface

Serial RGB Interface

(4) Maximum resolution and clock frequency

A. Parallel RGB

Resolution: 1920 * 1080

Clock frequency: 1920*1080*60*1.2 = 149MHZ

B. Serial RGB

Resolution: 800 * 480

Clock frequency: 800*3*480*60*1.2 = 83MHZ

Second, LVDS interface

(1) Interface definition

The LVDS, or low Voltage differential signaling, is an interface for differential signaling technology. It is a kind of digital video signal transmission method developed by American NS Company to overcome the disadvantage of large power consumption and EMI electromagnetic interference when transmitting wideband high bitrate data at TTL level.

The LVDS output interface uses a very low voltage swing (approx. 350mV) to transmit data via differential on two PCB traces or a pair of balanced cablesTransmission of low-voltage differential signals. The LVDS output interface allows the signal to be transmitted at a rate of hundreds of Mbit/s on a differential PCB line or balanced cable, resulting in low noise and low power dissipation due to low-voltage and low-current drive modes.
(2) interface typeA. 6-bit LVDS output interfacein this interface circuit, a single-way transmission, each base color signal using 6-bit data, a total of 18-bit RGB data, it is also known as 18-bit or 18bit LVDS interface. B. Dual 6-bit LVDS output interfaceThis interface circuit, the use of two-way transmission, each primary color signal using 6-bit data, where the odd path data is 18 bits, even the data is 18 bits, a total of 36-bit RGB data, it is also known as 36-bit or 36bit LVDS interface. C. Single 8-bit LVDS output interfacein this interface circuit, a single-way transmission, each base color signal using 8-bit data, a total of 24-bit RGB data, it is also known as 24-bit or 24bit LVDS interface. D. Dual 8-bit LVDS output interfaceThis interface circuit, the use of two-way transmission, each primary color signal using 8-bit data, where the odd path data is 24 bits, even the data is 24 bits, a total of 48-bit RGB data, it is also known as 48-bit or 48bit LVDS interface.

(3) interface features

A. High rate (general 655Mbps)

B. Low voltage, low power, low EMI (Swing 350mv)

C. Strong anti-jamming capability, differential signal

(4) Resolution

A. Single way: 1280*[email protected]0

1366*[email protected]

B. Two-way: 1920*[email protected]

Third, MIPI interface

(1) MIPI definition

The MIPI Alliance defines a set of interface standards that standardize the internal interfaces of mobile devices such as cameras, displays, baseband, and RF interfaces, thereby increasing design flexibility while reducing cost, design complexity, power consumption and EMI.

(2) MIPI features

A. High speed: 1gbps/lane,4gbps throughput

B. Low power: 200mV differential swing, 200mv common-mode voltage

C. Noise suppression

D. Less PIN,PCB layout is more convenient

(3) Resolution

mipi-dsi:2048*[email protected]

(4) Mipi-dsi mode

A. Command Mode

Corresponds to the parallel interface of the mipi-dbi-2, with frame Buffer, the brush screen based on the DCS command set, similar to the CPU screen.

B. Video Mode

Corresponds to the parallel interface of the mipi-dpi-2, the brush screen based on timing control, similar to the RGB synchronization screen

(5) How to work

A. Command mode of operation

Use DCS Long Write Command packet to refresh the gram.

the DCS command for the first packet per frame is Write_memory_start, for every frame synchronization

B. How video Works

Use sync packet to achieve timing synchronization, Pixel packet for LCD brush screen. The blank area can be any, and each frame should end with LP.

Four, HDMI interface

(1) Interface definition

A. High-definition Multimedia Interface

B. Digital interface, simultaneous transmission of video and audio

C. Transfer of uncompressed video data and compressed/non-compressed digital audio data

(2) History of development

A. In April 2002, Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, Toshiba, 7 companies set up the HDMI organization, began the system

Dedicated to digital video/audio transmission standards.

B. December 2002, Release HDMI 1.0

C. August 2005, Release HDMI 1.2

D. June 2006, Release HDMI 1.3

E. November 2009, release HDMI 1.4

F. September 2013, Release HDMI 2.0

(3) HDMI features

A. TMDS

Transition Minimized differential Signal

8bit~10bit DC Balance Code

Transmission of 10bit data per clock cycle

B. EDID and DDC

Enable connection between devices only

C. Transfer Video and Audio

Lower cost, more convenient connection

D. HDCP

High-bandwidth Digital Content Protection

(4) HDMI interface type

Display Interface Introduction