Research And Design Of NFC Tags Anti-collision Mechanism

Near field communication technology is a high-frequency, wireless, short-range communication technology which realizes data exchange and transmission of point to point by a non-contact way among the electronic devices. Initially, NFC technology only simply combines wireless radio frequency identification with interconnection technology and can communicate between two adjacent devices without any connected lines. This technology has already been widely used in the area of mobile commerce, service research and equipment interconnection.The paper starts from the aspects of research background, development status and application area of NFC technology and then gives a detailed description of the ISO/IEC14443A protocol standard used by the designed NFC tag. After understanding the tag work standards, I design command controlled module, anti-collision module and the EEPROM interface module respectively. The command controlled module designs a state machine to realize the transportation among every state when the tag receives different commands; Anti-collision module design mainly realizes a circuit diagram to choose tags when a conflict happens in the option of tags; Finally, based on the stored contents of EEPROM and requirements of read/write timing, interface module design of EEPROM will be completed. After given the state transmission diagram or circuit diagram of each module, we can write code of the design with Verilog language for simulation and verification. The designed circuit can realize command controlling, multi-tag anti-collision and read/write EEPROM operations after tested.Finally, I summarize and prospect the content of the paper, as well as make a plan of the future work. In the subsequent work, I hope to synthesize the code and use the synthesized gate-level netlist for placing and routing to carry out the finial layout.