Design And Realization Of Virtual Logic Analyzer

Logic analyzer (LA) is one of the most widely-used and important general-purpose instruments in digital system testing. It sets the engineers free from the heavy burden of monitoring the more and more complicated modern digital systems and diagnosing the failures. Virtual Instrument (Ⅵ) is developing rapidly in the area of industrial testing and represents the future direction for the traditional testing equipments. Field Programmable Gate Array (FPGA) becomes one of the most popular platforms for modern hardware design.Firstly, this thesis briefly introduces the logic analyzer and virtual instrument technology, elucidates the structure of the logic analysis system, its operating mechanism as well as characteristics. Besides, the features of Ⅵ, its software and hardware structure as well as the programming languages are also described since the combination of hardware and PC software is the pivot in the virtual instrument technology. Secondly, on the basis of the working principle and demand analysis of LA, the overall architectural design of our system is established. The proposed VI system consists of two major parts:the PC application (software) and the logic analyzer (hardware). The host PC and the LA are linked through a USB2.0USB interface for communication. The hardware part (consists of various modules including, probe module, clock module, the delay and latch module, glitch detection module, trigger recognition module, the storage control module, USB interface module etc.) is demonstrated in detail by separately discussing the design principles of each module. The FPGA technology and proper design concept are applied in the system design. Various trigger methods, such as the simple trigger, the count trigger, the sequential trigger, the delayed trigger are achieved and verified by simulations in terms of time sequence. Thus, the correctness and reliability of the circuit design are secured. The PC application is developed within the frame of VI technology and the communication between software and hardware through USB2.0interface is realized. Finally, the future work on the improvement of the system performance is proposed.