The Design And Realization Of User-defined Signal Generator Based On SOPC Technique

Many kinds of signal will be used to check up the system's capability in measuring or debugging. There are a lot of signal generators on sale, but they cannot fill all requirements. Quite a few signal generators can hardly fill the requirements in some special field. When people need a low-cost user-defined signal generator, it will be a problem. Many signal generators could not support user-defined signal, or are too expensive. They cannot fill the need of small low-cost designs. A low-cost, precision- suitable user-defined signal generator is needed in this state.Direct frequency synthesis technique, indirect frequency synthesis technique and direct digital frequency synthesis technique are the most familiar frequency synthesis technique. Direct frequency synthesis is a kind of early technique. It has short frequency switch time and low phasic noise. But it is also large, expensive and complex. Indirect frequency synthesis is also called phase locked loop technique. It is suitable to integration and miniaturization. And it also has good stabilization and little mixed signal. But it has long frequency switch time and large interval between two frequencies. Direct digital frequency synthesis is an up-to-date kind of frequency synthesis technique which is made of only digital circuits. It has wide bandwidth, short frequency switch time, and high resolving power. It also has continuous phasic output and is programmable. It is easy to use and has a high performance and a low cost.The paper uses direct digital frequency synthesis and SOPC technique to design a double-channel DDS module with VHDL language after anatomizing familiar frequency synthesis technique. Up-to-date techniques of Nios II and SOPC and EP1C6Q240C8, which is the production of Altera Corporation, are used. A useful user-defined signal generator is made by fitting the DDS module and peripherals together. The signal generator could make two independent signals which include sine wave, triangle wave, sawtooth wave, square wave and user-defined wave with a frequency range of 0-10MHz. The frequency of the signal increases of 0.5Hz and has an error about 0.5‰. The signal generator could also make two signals of the same frequency and a programmable phasic difference. The data of user-defined wave is send to the...