Data Acquisition And Processing System Based On DSP Technology And USB2.0

Data acquisition card is the AD interface card, which converts the output analog signals of the sensors to the digital signals, and transmits the digital signal to the computer. The traditional acquisition card is limited in data acquisition, and the task of signal processing and analyzing is finished by the computer, which leads to the reducing of the real time quality and even user's long time waiting in some high real time quality required fields. The users consume lots of time to configure the plugged data acquisition card, which doesn't have the capabilities of hot plugged and portable. The paper designs a portable data acquisition and processing system based on DSP and USB2.0 which breaks through the only function of sampling data of the traditional acquisition card, and realizes processing data on card, and have the advantages of hot-plugged and portable, and be adapt to the field test and measurement environment. The digital signal processor becomes the preferred utility for realizing digital arithmetic rapidly and precisely relying on its particular hardware and instruction architecture. The paper introduces the CPU structure,Memory composition,Peripheral resources and the addressing modes etc. The high-speed data acquisition and processing system requires not only fast and precise digital signal processing ability but also high data transmission bandwidth, which can transmit the mass of data to the PC. The interface used by the system is the crucial factor of the transmission bandwidth. Universal Serial Bus supports transfer rates up to 480 Mb/s,hot plugged,easy of expansion and full backward compatibility. Using the USB interface between the data acquisition system and the computer can satisfy this system's transmission bandwidth entirely. The paper introduces the feature and protocol of USB, and expatiates the design method of the data acquisition and processing system in detail. Based on the DSP and USB2.0 technologies, the paper designs a portable and high-speed data acquisition and processing system, which consists of input/output passage module, acquisition and processing module and computer interface module. Each module is composed of some electronic components, and the paper has made detailed hardware designing for each module. The software of the system is composed of DSP program ,the firmware,the device driver and the host application program. The paper introduces the main DSP program and the DMA and the INT2 interrupt service program for system's one-channel and multi-channel working mode. The system's firmware is designed by the KeilC51 tool. The device driver is designed by the Microsoft's device drive kits, and the application program is developed with the Visual C++ 6.0 tools. Finally, some conclusions and further research prospect are provided.