Analysis of AM335x platform asynchronous control card system

szypf2011

Analysis of AM335x platform asynchronous control card system [Copy link]

 

AM335X has rich hardware peripherals and Linux-based software solutions, including GPU Composition module, which can provide complete multi-layer overlay and zoom functions, and is very suitable for asynchronous control card applications of full-color LED display walls. The following analyzes the system requirements of its main chip from both hardware and software aspects. For example, Yingpengfei embedded AM335x development board:

AM335x development board information:

EVB-335x_cn.pdf (2.7 MB, downloads: 9)

2018-8-24 11:08 上传

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CoM-335x_cn.pdf (1.59 MB, downloads: 9)

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Hardware part

From the hardware point of view, the video processing module is mainly composed of two parts: the minimum system and the peripheral module.

Minimum system

The minimum system consists of four parts: main chip, power system, DDR and storage; different levels of full-color screens have different requirements on the processing power of SOC, and the specific requirements are explained in the software part.  Peripheral modules Audio interface, LCD interface: the basic requirements of LED display wall; Network interface: 100M or even 1000M network port can effectively ensure the high efficiency of display content update; USB interface: convenient for system upgrade and expansion of various USB-based peripherals; SD card/TF card support: convenient for system upgrade and local update of content. In addition, asynchronous cards are generally placed outdoors with LED display walls, so industrial-grade chips that can work in a wide temperature range are required.

Software part

The software part is mainly composed of two parts: operating system and application software. In the asynchronous control card industry, the mainstream operating system has chosen Linux; the application software mainly includes three parts:

Multimedia part

For decoding audio and video code streams, full-color screens are mainly divided into two grades: high-end and mid-to-low-end: high-end, video resolution and display resolution are required to be above 720p resolution; mid-to-low-end, video resolution and display resolution are within 640x480. Since LED walls generally display a large physical area and high brightness, the frame rate of the video stream is required to be higher, requiring more than 25 frames per second. Therefore, for high-end products, a main chip with a video hard decoding module is generally required, and its price is generally higher; for low-end products, soft decoding can be used, so a main chip with strong computing performance is required, which has a better cost advantage.  UI part: Used to display subtitles, pictures, etc., and handle the overlay of UI elements and video layers. The overlay part involves transparency, size change, etc., and has great computing requirements, so the main chip needs to have relevant hardware acceleration modules.  Remote control section] This part mainly realizes the functions of remote control of each control card by the host computer, content update, etc. This part is generally realized through the network application layer, and each control manufacturer has its own protocol! ! !

This content is originally created by EEWORLD forum user szypf2011. If you need to reprint or use it for commercial purposes, you must obtain the author's consent and indicate the source