Research And Implementation Of Extended Systems About PC/104 Bus Controller And Multi-UART Based On FPGA

The UAPT and PC/104 bus are very popular with customers and adopted widely in Embedded Systems field, especially in industrial control field due to they are simple in structure, easy to operate, reliable to work, strong in anti-interference capability and rich in applicable resources. It is common in industrial control field that a main-controller communicates with many equipments, which requiring several UARTs. Currently, there are two methods in market for extension of multi-UART: simulating using software and specific chips for extension of multi-UART. However, both of them are expensive and exist great wastes of resources, can not satisfy the demand of the large number of serial communication interface equipments. PC/104 bus controller usually employs the X86 architecture processor as the control chip, however, it is expensive and has high power consumption and large size.FPGA has the feature of being programmable and can flexibly implement the functions needed. After 20 years of development, FPGA has gained many advantages: its high integrated has been greatly improved up to several million gates; its speed has been ever increased with its highest main frequency up to 600 MHz; its power exhausting has been decreased and its core voltage is only 1.2V; and its industrial level product can be used in the environment that temperature is between -40℃and 100℃.FPGA has becoming one of the development tendencies of IC industry. FPGA is realized by hardware, thus is better in stability than software, quicker in speed and more economical.The dissertation analyzed system functions, compared several feasible cases and decided to use FPGA. Then starting from FPGA's designing process, the paper made a general plan for the design, determined the chip type, and described the system power module and FPGA configuration module. It elaborated upon PC/104 bus's protocol and operating timing sequence, summarized the main function of PC/104 bus controller into FSM, used Verilog HDL to describe it and simulate its function in ModelSim. Starting from UART's operating principle and data transferring format, this dissertation divided configurable multi-UART's function, utilizing two FSMs to realize the function of receiving and sending data, and simulated in ModelSim too. The dissertation combined the two parts and made function simulation, and synthesized by Synplify Pro, at last actualized in PFGA of Xilinx company's Spartan-3, satisfied the expanded system's needs of PC/104 bus controller's function and sixteen configurable full-duplex UARTs. At last this dissertation made texts on the spot.