基于PCI-E总线的北斗导航授时卡Linux驱动设计

Design and Implementation of Driver of Beidou Navigation Timing Card under Linux PCI-E

摘要:

为提高Linux系统时间的精确度,设计了PCI-Express接口的北斗授时卡以及驱动程序；授时卡通过北斗卫星导航信息接收模块接收时间定位信息并输出至FPGA(Field－Programmable Gate Array,现场可编程门阵列),FPGA利用状态机检测出时间位置信息,并存入IP核创建的虚拟双口RAM中；当PCI-E驱动芯片接收到读取当前时间命令时,将虚拟双口RAM中时间数据传输至PCI-E总线供上位机读取；实验编写了Linux系统设备驱动程序,包括驱动的编译、加载,利用图形界面开发工具GTK+编写授时测试软件；打开授时测试软件,通过指令使能授时卡PCI-E驱动芯片硬件中断,检测到FPGA输出的中断信号,测试软件进去中断服务程序读取PCI-E总线上的时间信息,并在目标栏中显示；试验结果证明:在Ubuntu Kylin系统平台下授时测试软件运行稳定、界面简洁,且授时精度达到100纳秒。

Abstract:

To improve the time accuracy of Linux system,a Beidou timing card driver under PCI-Express interface is designed. Timing card transmits time and location information to the FPGA (Field-Programmable Gate Array) by Beidou satellite navigation receiver module. FPGA decodes time and location information by using state machine,and creates a virtual double port RAM to store data by using IP core. When the PCI-E driver chip receives a command to read the current time,time data will be read from virtual dual-port RAM and transmit to PCI-E bus for the host computer. It programs timing card drivers for Linux including the driver compilation and loading,uses GTK+ graphical interface development tools to programming test software. Opening software and sending command to enable PCI-E driver chip hardware interrupt,when an interrupt signal output from the FPGA is found,the software runs interrupt service process will be tested and the time information on the PCI-E bus will be read and displayed in the column. Test results show that:software is stable and the interface is simple,and the timing error is 100 ns under Ubuntu Kylin system platform.