Arbitrary Waveform Generator Based On PCI Bus

With the application of the electronic and computer technology in measurement instrument, a new signal generator—Arbitrary Waveform Generator (AWG) emerges as the times require. It is wildly used in the modern testing field. In the paper, a new type of AWG is presented for the ubiquity problems which has a small memory resources for waveform data, low-speed or complex to handle.In the design, a scheme that used special DDS chip and high speed SDRAM to construct AWG system based on DDS theory was proposed. It made the AWG has the function that could generate large storage and long periodic waveform or reproduce waveform which had been sampled. Because the PCI Bus is a high speed bus that data and address transmitted in the same bus, we use a special PCI chip to fulfill the control that PC computer to card. In the same time, through the programmable chip (FPGA) to fulfill the function of SDRAM controller, system timing logic control and I/O control. At last it finished the design of high speed D/A conversion, filter, output drive circuit and software design of interface. The main contents of this paper are following:1 After analyzed the theory and structure of DDS, a scheme that use special DDS chip and SDRAM to build system is proposed. Through this scheme we can get an AWG which has a high-resolution and high stability.2 Finished analog circuit design of system, realized control that PC computer to card by PCI bus. Meanwhile, a scheme of multi-filter has been proposed after the analyzed the of output waveform. The user can choose suitable filter to ensure the pure of output waveform.3 Finished the research of large storage and utilizing FPGA to design the SDRAM controller. Fulfilled long period waveform storaged and resolve system's main logic decode problems, meanwhile, improved the integration and reliability of system.4 Introduced software design and got a friendly operation interface by virtual instrument. The paper introduced the way of utilizing Windriver to build DLL file.5 Make out a test scheme accoding to design demand and proposed some effective solutions to the problems which are encountered in system debug. At last the main test result which indicated the design achieves the demand.