Hardware Design And Implementation Of Train Full Digital Emergency Intercom Unit

Along with increase in the train communication digital level, the requirements of train emergency communication equipment are rising. On the one hand, emergency communication based on analog audio transmission technology can not meet the audio quality and reliability requirements any longer. On the other hand, MVB(MVB-Multifunction Vehicle Bus) has been widely used in the train communication area now. Therefore, the train emergency communication equipment based on MVB has a very promising future.By the researches on MVB bus and the understanding of the needs of MVB equipments, the plan of designing the train full digital emergency intercom unit based on MVB and FPGA (FPGA-Field Programmable Gate Array) has been proposed. Through the selection of the chips, the design of the hardware circuit, the design and implementation of the FPGA controller and the test of the cards, the plan is verified.This paper firstly introduces the train communication system development and basic knowledge of MVB. Secondly, by the analysis of the requirements of train full digital emergency intercom unit based on the feature of MVB and the actual needs of customer, the design plan based on FPGA, TLV320AIC23 audio codec chip and MBI5036 drive chip is selected. Thirdly, the hardware design platform and procedure, schematic design and PCB(Printed Circuit Board) design are described in detail. Schematic design includes system power circuit, clock circuit and MVB interface circuit, speech function circuit, LED drive circuit and FPGA configuration circuit. PCB design includes PCB layer structure design, the layout of PCB and post-treatment. Fourthly, this section mainly introduces the logic design of FPGA and the implementation of the function module based on FPGA. Then, the emergency intercom unit are debugged and tested. The conclusion and the future work are discussed at the end of this paper.