基于FPGA的CAN接口协议设计与实现

Having been widely used in factory field equipment layer, CAN (Controller Area Network) field bus technology has many advantages,such as low cost, simple Network structure, high real-time performance, hign reliability and high maintainability. MCP2515, product of Microchip, is a CAN control chip integrated with protocol specification. The same as the other CAN control chip, it is mainly drived by the MCU. But MCU based CAN interface has some problems like incompatible electric parameters and poor generality. In this paper, a method of using the FPGA to implement CAN bus protocol is introduced, with the purpose of improving the performance and efficiency of the CAN controller. A bottom-up method is used to desigh the approach.First, design the SPI interface, then implement reading and writing registers of the CAN chip, and finally use each module to implement the CAN interface controled by FPGA. The modelsim simulations and in-circuit debugging results are shown in this paper.