Design and realization of multi-function serial port with high-speed/large-capacity/asynchronous FIFO

Serial ports, such as RS232, RS422, RS485, and so on, have been more and more applied in industrial instrumentation and automatic devices. In the field of automatic testing, designing a multi-function serial port will create great convenience to workers. Meanwhile, the amount of data becomes larger and larger. In this case, we design the multi-function serial port with high speed and large capacity. However, dedicated high-speed FIFO chip is expensive and has limited capacity. Then we put forward using Field-Programmable Gate Array (FPGA) to control Synchronous Dynamic Random Access Memory (SDRAM) to realize this FIFO. This paper describes the method of using FPGA to design SDRAM controller and multi-function serial port. This design has been applied in multi-function serial interface card.