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This article will explain in detail the differences between the LCD screen RGB interface and the MCU interface. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

Our commonly used LCD screen not only has the familiar interface mode of SPI and 8080 parallel port, but also has many kinds of communication modes such as RGB, VSYNC, MDDI and so on.

Here is a brief summary of the difference between MCU screen and RGB screen, as well as the characteristics of other types of screens:

The main difference between the MCU-LCD screen and the RGB-LCD screen is the location of the video memory:

The video memory of RGB-LCD is served by system memory, so its size is only limited by the size of system memory, so that RGB-LCD can make a larger size, like now 4.3 can only be counted as gate level, while 7 and 10 screens in MID are beginning to be used in large quantities.

At the beginning of the design of MCU-LCD, as long as the memory of the single-chip microcomputer is small, so the display memory is built into the LCD module. Then the software updates the video memory by specifically displaying commands, so the MCU screen often cannot be made very large. It also shows that the update speed is slower than that of RGB-LCD.

The data transmission mode of MCU-LCD screen is also different from that of RGB-LCD screen:

The RGB screen only needs to display and store the organized data. After starting the display. LCD-DMA automatically sends video memory to LCM through the RGB interface.

The MCU screen needs to send the command to draw points to modify the internal RAM of MCU. (that is, you cannot directly MCU the RAM screen) so the display speed of RGB is obviously faster than that of MCU, and MCU-LCD is also relatively slow in terms of video playback.

For the LCM of the RGB interface, the host outputs directly the RGB data of each pixel and does not need to be transformed (except GAMMA correction, etc.). For this kind of interface, it is necessary to have a LCD controller in the host part to generate RGB data and point, line and frame synchronization signals.

In other words, the traditional MCU screen display data is written to DDRAM, while the RGB screen data is not written to DDRAM, directly writing screen, reading and writing speed is faster.

VSYNC mode:

In fact, this mode adds a VSYNC signal to the MCU mode, which is applied to the motion picture update, which is very different from the above two interfaces. This mode supports the function of animation display directly, and it provides a solution to realize animation display with minimal changes to the MCU interface.

In this mode, the internal display operation is synchronized with the external VSYNC signal. Can achieve higher speed than the internal operation of the animation display. However, due to its different mode of operation, this mode has a limit on the rate, that is, the writing rate of the internal SRAM must be greater than the rate of displaying and reading the internal SRAM.

MDDI mode:

The interface MDDI proposed by Qualcomm in 2004 can improve the reliability of mobile phones and reduce power consumption by reducing connections, which will replace the SPI mode and become a high-speed serial interface in the mobile field.

This is the end of this article on "what is the difference between LCD screen RGB interface and MCU interface". I hope the above content can be helpful to you, so that you can learn more knowledge. if you think the article is good, please share it out for more people to see.

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