Research And Design Of A Virtual Pattern Generator

Along with the advance of society and the development of technology, digital electronic products are continuously updating and data domain testing technology which is closely related to digital electronic products is given more attention. Foreign enterprises set foot in the manufacture of data domain testing instruments so early that they occupy a large proportion of the market share with the instruments’ high prices. There is a serious lack of this kind of instruments in our country, which leads to the situation that universities are short of data domain testing devices and severely affects talent training in the field of digital information. This shows an urgent need to research and develop data domain testing instruments at a low price, facing college science and engineering laboratories.VIIS-EM is short for virtual instrument integration system-electronic measuring, which is self-developed in Jilin University. In the field of data domain testing, the system has a logic analyzer as the receiver of digital signal and yet faces the shortage that there is a lack of a digital signal transmitting terminal.To solve the two problems above, by reviewing a lot of literature, the paper presents a design of a pattern generator. The design, based on virtual instrument technology, is realized as a function module of VIIS-EM.Firstly, The hardware part of the pattern generator, centered on single-chip and FPGA, with components, for example, SRAM and voltage converter chips as operation units, realizes functions of pattern signal’s storing, generating, controlling frequencies and adjusting voltage standards.Secondly, Interface in PC and dynamic link libraries is developed based on the environments of Lab VIEW and VC++, implementing editing pattern, setting the frequency of the pattern signal, modulating the voltage standard and communication with the hardware part via a USB port.Finally, Combined with the logic analyzer module and the oscilloscope module of VIIS-EM, by the use of self-designed digital checking circuits, the feasibility, the stability and the reliability of the pattern generator are tested. The testing results turn out that the instrument can reach the expected goal of the design and satisfy the need of experiments and teaching in electronic majors of colleges.