Data Transmission And Multi-threaded Processing Under UClinux

As we all know,sonar is one of the important equipment of naval vessels and submarines,no sonar,ships and submarines unable to move.In some research units or naval training,need sonar system,due to its specificity,rarely in practice,but sonar systems also need to carry out research or training,therefore,low-cost sonar simulator emerged.By processing different data of hydrological simulation environment,the marine environment,the target state and signal characteristics,the data processed display on the computer,we can simulate the marine environment on land.In this paper,the platform based on ADSP-BF561,do the research of the transmission of real-time data and the process of real-time signal.Experimental data prove the real-time speed data transfer rates and real-time signal processing meet the requirements of sonar simulator.Thesis base on BF561 digital signal processor,build sonar simulator systems,based on the compatibility and portability requirements,combined with the actual needs of sonar simulator,using Ethernet interface as the data transfer interface,due to the complexity of the Ethernet protocol and sonar simulator data transmission rate requirements,porting the U-Boot bootloader and uClinux operating system on BF561 platform,use U-Boot boot uClinux operating system,tailoring and optimization of uClinux operating system to run smoothly and stable on the BF561 platform,in the uClinux operating system migration Ethernet card drivers,use uClinux operating system to a more efficient use of the Ethernet interface,in the uClinux operating system achieve a way to use B core of BF561,then can fully use the resources of BF561 to meet the needs of real-time signal processing.Thesis achieve the TCP / UDP protocol to transfer data under uClinux operating system,comparative analysis the data of transfer rate under TCP and UDP protocols,when using the TCP protocol for data transmission existing a problem,the time for the first time receive data is too long,reaching the second stage,such a long time can not meet the DSP real-time signal processing,in the paper use add instruction methods to avoid this problem,namely,for the first time received instruction from the host computer PC,thus avoiding the received data for a long time,according to the experimental data,the add instruction method can improved the problem,when using the UDP protocol for data transmission,the UDP protocol data transmission rates faster than TCP protocol,but there is a problem that the packet loss,usinginsertion interval in the send buffer method in the paper,the experimental data show that can improve the UDP protocol packet loss,experimental data and analysis to the conclusion choose sonar simulator data transfer protocols and methods,achieve FFT algorithm on DSP,and verify it under VDSP environment,ported the algorithm to the uClinux operating system,in the uClinux operating system achieve multi-threading technology,and use multi-threading technology in real-time signal processing program,analysis and comparison about the impact of data transmission in real-time signal processing,experiment data show that multithreadding technology can improve the efficiency of real-time signal processing.