The Digital Baseband Design Of The NFC Tag Based On The Protocol Of ISO/IEC 14443-A

The Near Field Communication (NFC) technology is a short-range wireless communication technology, evolved from a combination of RFID and interconnection technologies. By integrating induction reader, tag and point-to-point function in a NFC chip, this technology can provide the rapid secure communication between devices in order to achieve identification and data exchange. NFC is a recently developed new technology and the technical standard is still in perfect, so the study about NFC technology becomes important. This article researched the design and implementation of digital baseband for passive NFC tag chip according to the protocol of ISO/IEC 14443-A.In the beginning of the paper, it elaborates the research background and significance of this topic, introducing the basic principle of NFC technology and its characteristics and advantages, also the development history of it; Secondly, put forward that the type chip we designed belongs to the tag 2 type, and its wireless communication interface is compliant with the protocol of ISO/IEC 14443-A part 2 and part 3, then the key technologies involved were discussed and analyzed in detail; Again, the overall architecture of tag chip is introduced, it consists of antenna, analog front end circuit, digital baseband and storage units. The digital baseband plays a key role in one NFC tag and it can embodiment concretely of the whole protocol thoughts. This paper is to complete the design of the digital baseband. Based on analyzing the protocol of ISO/IEC 14443-A and the overall architecture of tag chip, the system architecture of digital baseband circuit and the module partition in detail are focus completed. And then detailed design the decode module, check module, state control module, memory access control module and encode module etc. The whole digital baseband circuit is described in Verilog HDL in RTL design, after that, Writing testbench according to the protocol of ISO/IEC 10373-6, and simulated by Modelsim with the use of the testbench; Finally, the full text is summarized and the ameliorating direction in the future is pointed out.The results show that, the digital baseband designed can make the tag state transfer correctly, and realize the tag inventory, read, write, as well as lock operation.