基于FPGA的多通道智能CAN卡设计

Design of multiple channels CAN card based on FPGA

针对CAN网络控制系统对实时性和可靠性要求,文中提出了一种基于FPGA的智能多通道CAN卡设计方案。通过FPGA设计了可变字节长度的主模式SPI接口电路,简化硬件结构,设计了双口RAM实现PCI总线和网络数据交换。设计了基于CH365的PCI接口电路可以和ISA模式共享,设计了变压器隔离电路功耗低可靠性更好。板卡设计了微处理器通过板卡配置按照TTCAN协议自动完成CAN数据交换,可以当作普通卡使用,免去了复杂的驱动调用,方便使用。最后设计实验测试板卡在自动传输功能时实时性和可靠性,结果满足要求。

In order to meet CAN network control system for real-time and reliability requirements,this paper presents a smart and multi-channel CAN card design scheme based on FPGA. The variable-byte SPI master mode interface circuit is designed through FPGA,the hardware structure is simplified,and a dual-port RAM implement PCI bus and network data exchange are designed. PCI interface circuit is designed based on the CH365 and it can be shared with ISA mode. The transformer isolation circuit is designed that can implement lower power and higher reliability. The microprocessor is designed on the board that abides by TTCAN protocol can automatically realize CAN data exchange,and it also can be used as a normal card,eliminating the need for complex drive call,and easy to use. Final designed experimental test reliability and real-time of board that worked under the automatic transmission mode,the results meet the requirements.