ASIC-based Network Set-top Boxes Design Under The Android Platform

In recent years, the construction and development of China’s telecom network and broadband network is very rapid, the increasing popularity of home broadband and 4 g broadband communication services gives users fast access to the Internet experience. How to realize the integration of embedded mobile devices, telecommunication network and Internet service has become an important research direction in the development of mobile equipment industry. TV set-top boxes, which as the manifestation of the concept of "Triple-play" in construction of Wisdom City, has been in continuous development to meet the growing needs of user. Now under the wave of the development of mobile internet, the network set-top box arises with intelligent operating system, which includes both the open network service and a better Interaction Design, can play your favorite videos and use the third party software independently, that realized the integration of traditional set-top box and Internet service.Compared with the traditional set-top boxes, to meet the needs of playing the high-definition video and streaming media, intelligent network set-top boxes have faster speed and stronger ability of video decoding. In this paper, aiming at this requirement, transplanted from the tablet computer program, an Android system network set-top box was designed based on Application Specific Integrated Circuit(ASIC). With low power consumption and low cost, the system designed in this paper has a strong ability in video decoding, especially in processing streaming media. With unified design standard, this operating system has a stronger versatility and portability compared with the traditional Linux system.During the design work, with the analysis of several existing tablet solution, we determined the transfer request and the hardware platform architecture based on A31 s processor first. Then based on the modular design method, we finished the circuit schematic diagram design of the minimum system, video output, network communication and power management module, the working principle of some key modules are given in the article. After the design of hardware circuit, the Android4.2 system was transplanted from the source platform by the analysis of the Android system architecture and the system transplant procedure.Then, according to infrared driver design needs, we analyzed the kernel character device driver structure, the data structure and working mechanism of Input subsystem. The IR driver was made in the Input subsystem.Finally, against the unexpected power-off code missing, we optimized the NAND flash driver.At the end of the paper, we introduced the complication of Android system compiler and programmer, and the test results of the circuit and the input and output functions of the set-top box are given. The results showed that the system functions normally and well-run, TMDS differential signal is stable, and achieved the desired requirements.