Data Acquisition System Based On SOPC For Next-Generation Versatile Disc

Channel detection for compact disc is one of the core technologies of compact disc reading channel. Channel detection is meaningful for the servo system design and bit error rate testing of Next-Generation Versatile Disc. Research on channel detection needs data of digital signal, while the RF signal of the optical head is an analog signal. Therefore, converting analog signal to digital signal and the storing the data is firstly needed. Data acquisition system is the basis for channel detection of Next-Generation Versatile Disc.The paper introduces the theory of sampling theorem, the basic concept about FAT32file system and the technology of the Nios II SOPC system, according to the characteristic of the Next-Generation Versatile Disc data acquisition system, analyses the needs of the data acquisition system, and shows the architecture of hardware and software for the data acquisition system. The system hardware mainly includes the Nios II SOPC system, the Avalon peripheral interface for the data acquisition card, data cache and data filter modules. System software includes main program, FAT32file system and the file system dependent underlying drivers and communication protocols. What’s more, this paper gives the detailed design of the system, defines the specification for the Avalon peripheral interface of the data acquisition card, in order to match the speed difference of the high-speed data acquisition card and low-speed peripheral, uses cache to smooth the speed difference between them, gives the specific design, utilizes a FAT32file system to store the data collected, and expounds the basic data structures and functions for data storage. Then a Nios II SOPC system for Next-Generation Versatile Disc data acquisition is built, and the concrete realization of signal processing, analog-digital conversion, data transfer and file storage modules are given.In this paper, the test for the data acquisition system uses MATLAB on Windows XP operating system. A program for test is designed. First, the data acquisition system samples a sine wave to verify the correctness of the system. Then the system samples and stores the RF signal of Next-Generation Versatile Disc. The test result shows the data acquisition system can sample the RF signal and store the data correctly, and the system can meet the requirements for further study about the Next-Generation Versatile Disc channel detection.