Rate Adaptable ISO7816 Interface Circuit Design For Mobile Payment

In recent years, mobile payment has become hot in the field of small-amount payment,and the near field communication solution using SWP-SIM smart card with ISO7816 interface circuit to complete the single half duplex communication of the general data between the SIM card and IFD(Interface Device),which has the advantages of simple structure, good compatibility and makes the most ideal mobile payment solution rapidly. Compared with the existing SWP-SIM card, the technology of ISO7816 interface circuit of foreign products is mature, but costs too much, and we do not have independent intellectual property rights,as to the current domestic products, there are still some problems such as high power consumption, large scale of circuits and etc.To meet the application requirements of the smart card interface: on one hand, high transmission speed for large scale of data; on the other hand,considering the demand of low power dissipation, we design the data rate adaptable transmission process. First of all,this paper realizes real-time monitoring of clock frequency and relative parameters, and makes dynamic adjustment of clock frequency in the corresponding circuits; then, in order to reach high data rate, this paper presents the design and implementation of direct memory access(DMA) working mode, high speed asynchronous data cache FIFO and configurable ETU TIMER to improve the hardware circuits for higher data transmission efficiency; in addition, we need to meet the requirements of low power consumption, this paper designs and realizes the clock stop and sleep-wakeup strategy.This paper has set up the testing environment of the hardware circuits on the FPGA platform,the valid communication rate can reach 208.14kbit/s, compared with 115.2kbit/s of the same products of UART serial interface(which also supports DMA standard data transmission),the performance is nearly doubled. Finally, based on SMIC 130 nm eFLASH process,the circuit scale of the interface is 4.2K gates,we test the successfully fabricated chip using industry standard smart card test instrument MP300,whose performance is better than the domestic similar products.