The Design Of High-speed Continuable Signal Playback Module Control Software

The signal playback module that can produce and playback the data obtained by actual sampling or simulation,is used to simulate and reproduce some real filed scenarios,in order to meet the specific needs of scientific research and application in military,aeronautics,communications and other fields.With the continuous increase of sampling frequency and data storage depth,the requirements for the playback rate,data storage capacity,and continuous playback time of the signal playback module are increasingly exacting.Therefore,it is an urgent need to research signal playback modules with high-speed,continuous,and long-time playback capabilities.This paper studies the high-speed signal playback module control software that can deliver the data stream in a high speed,stable and continuous manner to the hardware playback device by effectively controlling the data transmission task,without independent storage device to cache the data.The main contents of this paper are as follows:1?Demand analysis and overall scheme design of high-speed signal playback module.First,by analyzing the high-speed signal playback module's single-channel maximum playback rate of 100 MSPS,vertical resolution 16 bit,four-channel playback index requirements,it is concluded that the transmission rate of the stable data stream needs to be greater than 800 MB/s.Then,by comparing the common technical solutions of the high-speed bus communication interface module and the mass data storage module,a PCIe high-speed bus is used as a data transmission interface,and a scheme that without independent storage device to cache the data is proposed.Last,the overall design of high-speed playback module hardware and control software is proposed.2?The design and implementation of bus and device driver module,which is mainly used to drive the PCIe bus and playback device.First,by analyzing the Linux device driver model and PCIe device configuration space,it is implemented the Linux character device driver under PCIe bus.Then,the DMA module based on the descriptor transmission mode is designed to release the CPU during the data transmission,which ensures the data transmission rate.Last,using the real-time operating system Xenomai and RTDM driver module,and using the interrupt pipeline mechanism to improve the module's response to the interrupt signal,to ensure the requirement of data transfertask's time limit.3?The design and implementation of data transmission control module,which is mainly used to control and coordinate the mass data read from the host computer memory module and deliver the mass data transfer to the hardware playback device.First,a RAID-0 mode SSD array is designed for storing the mass data,and its high-speed sequential read performance provides sufficient data throughput for the rear stage.Next,a file mapping method is used to read the data,which can reduce the unnecessary copying process of the data and can improve the reading efficiency of the data file.Then,multi-thread technology and message queue technology are adopted to achieve efficient control and scheduling of data transmission threads and data reading threads.Last,the data and message communication mechanism of inter-module is designed to ensure the efficient interaction between various modules in the data transmission process.4?Selecting test tools and test methods to set up the test platform,in order to test and verify the control software of high-speed signal playback module.The correctness,stability,and transmission rate of the data transmission are tested,and the function of high-speed,continuable,and long-term playback for mass data is verified.After testing and verification,the high-speed continuable signal playback module control software designed in this paper can effectively control the mass data read from the host computer SSD array transfer to the hardware playback device in a high-speed,stable and continuous manner,through the PCIe bus interface.And it is supported long-term,continuable playback for mass data at a rate of 800MB/s by the DAC module.