Hardware Design Of ABS-S Digital Satellite Set-topbox Motherboard

June 9, 2008, with the " Chinasat 9" satellite successfully launched into space, China has its own the first live broadcasting television satellite with anti-interference ability. "Chinasat 9" satellite system was developed by China with independent intellectual property rights channel coding standard ABS-S (advanced satellite broadcasting system) .This standard is a new generation of satellite transmission of technical standards that the NationalSecurity Administration security organizations developed in order to ensure the safety of live ,which can achieve international advanced level.It is not compatible with foreign satellite transmission standard, coupled with other technical measures to ensure the safety of direct broadcast satellite business.China has a vast territory. In order to solve the issue that farmers in remote areas are difficult to listen to radio and watch television, the state start the every village access project which can expand radio and television coverage in rural areas and meet the aspirations of the visual needs of working people. ABS-S is a digital satellite set-top boxe to support the domestic ABS-S satellite digital TV broadcast standard set-top box and is one of the technical programs that "Every Village" project in direct broadcast satellite way mainly uses。In this paper, it is in this context of development in line with China's development of satellite digital television satellite digital TV set-top boxes. In the ABS-S digital satellite set-top box development projects, I am responsible for hardware design and realization of the ABS-S digital satellite set-top box motherboard. this motherboard used Power Logic software to design it'schematic and use Power PCB software to draw it's PCB.This motherboard used Conexant's CX24146 digital TV decoder chip as the core of thesystem, the external circuit including ABS-S High Frequency board, SDRAM, FLASH, DAC, UART, etc.. ABS-S high-frequency board is mainly linked by Zhongtian Lianke's demodulator chip AVL1108 and SHARP6303 tuner.Set-top box software is stored in FLASH memory, available online to input the imulation program through the JTAG port. FLASH usedAM29LV320DB-90EI to store the system control program. EEPROM used AT24C64A to read and write with IIC bus control for data storage of channel and program. Memory which MPEG-2 decoder need is to shares a piece of SDRAM with a capacity of 64Mbits, used to store intermediate data, which is the data area and stack of program running. It can receive the satellite signals and make the signals convert into TS streams which are provided to the back-end decoder chip through a simple interface.Finally hardware design and implementation of the motherboard was completed. Through the actual simulation and testing, it can reach the Indicators which set-top boxes is required.This prove that the design is simple and stable.So it can be used as set-top box solutions.