Design And Implement Of Gap Technology Card Based On FPGA

The Internet has brought tremendous development and changes to various industries,but also caused important information security issues.Firewall software is a widely used network security measure,but there are also some loopholes at the aspect of operating system,application protocol,link connection and security policy.The most secure way is the physical isolation technology of the network.The internal network and the external network are physically separated.There is no connection,no support for TCP/IP protocol,and no dependence on the operating system.However,physical isolation brings serious inconvenience to data communication and exchange.GAP technology is an information security solution to communicate under the premise of ensuring security.It meets the security requirements of physical isolation between intranet and extranet,and can exchange data efficiently.GAP technology has important practical value.According to the requirement of application,this paper presents the hardware and software design of Gigabit rate switch card based on FPGA.The main work is as follows:(1)The hardware circuit of the switch card based on Altera Cyclone IV Gx series of FPGA chips is designed,which mainly includes JTAG interface circuit for on-line debugging,AS interface circuit for downloading the configuration files of FPGA,clock circuit,key indicator circuit,PCIe interface circuit and custom SMA interface circuit.(2)Designed the gate switch card's FPGA software,realized the high-speed data transmission between the FPGA and the host through the PCIe interface,realized the Gigabit rate data transmission between the gate switch cards through the custom SMA interface,and realized the data transmission mechanism of the ferry exchange.(3)With the host driver,the function and character of the switch card are tested.The comprehensive test results show that the switch card meets the design requirements and the data exchange rate can reach 750 Mbps.