The Development Of Discrete Semiconductor Testing System With CPLD Simulated System Bus

With the advancement of informationalization and the applying of information technology in traditional industrials, there is a great improvement in the field of packaging and testing of discrete semiconductors and a great demand for small-sized and middle-sized discrete semiconductor testing equipments arises; therefore, it is quite necessary to develop new types of discrete semiconductor testing systems by seeking a balance between price and quality.This article describes our work in the design of a new type of discrete semiconductor testing system for the ChangJiang Elec.Tech with the development of embedded system and programmab1e logic device application technology. We determined the constructing structure of distributed testing system jointly, designed the CPU board to realize our defined system bus and debugged AD/DA board to accomplish high-precision testing of semiconductor. We also finished the testing techniques editing software program and achieved to connect the testing machine, filtering machine and the computer. Meanwhile, we brought other new methods about controlling the whole testing system and researched how to use ARM in embedded system, including hardware design, operation system transplant and application program.This thesis firstly introduces background of the article and the necessity of developing new type of discrete semiconductor testing systems and the design scheme of this project. Then article presents the development of embedded system and programmab1e logic device application technology, discusses the feasibility and advantage about using these technologies in testing system, and describes how to simulate the system bus with CPLD.After analyzing the typical testing circuit, the design and adjustment of high-precision AD/DA circuit are presented.Subsequently, this thesis states the structure and function of the applications on the Personal Computer, describes the communication stipulation.Finally, this article gives two new methods of controlling the testing system and explanation of methods for further development.