Study On Data Receiving Method For Multi-serial Communication System Based On USB

Multi-serial Communication System based on USB for receiving four output signals(the information of inertial navigation products in different locations,rate and temperature) at the same time is designed in this paper.According the receiving data and processing formula to calibrate the index of inertial navigation products.So this system is very important for the calibration of inertial navigation products.Firstly,development of inertial navigation system and test technology is introduced in this paper. Then, in the study of several feasibility reports, the overall design of this system is given. In this system, two chips of Cypress EZ-USB FX2LP series and other components are sured to build USB peripheral circuit. And USB is introduced to achieve high-speed data transmission between CY7C68013A and PC computer. The application and USB driver are compiled by VC++6.0 to real-time display the information of each serial port in a second and save the original data. At the end, briefly describe the USB technology and the working principle and methods of CY7C68013A's serial port.Design of this system can be devided into two parts which are hardware design and software design. The FIFO structure and configuration of CY7C68013A are introduced in this paper. Then electric schematic diagram is designed and hardware platform of this system is constructed, such as voltage conversion, logic level translator, I2C bus, USB interface and so on. Software including FX2LP firmware programming, USB driver and application is very important. The respondence to serial requests is realized by firmware, and the compiler environment is Keil. Data buffering and uploading are controlled by firmware too. Meanwhile, setting out the detail steps of modifying USB driver in Windows system environment combine VC++6.0 with DDK. Application is compiled by VC++6.0 and communicates with USB driver by I/O control command. By the use of timer and multithreading, realizing that receiving,saving and computing the data of two USB devices in sync. Finally, test for this system has been carried out, the operation process has been given at the same time.According to the numerical analysis about test, some conclusions can be drawn.The outputs of four inertial navigation products can be sampled at the same time without missing. And all functions of this system are tested to meet the design requirements.