Abstract
With the development of Digital Integrated Technology and Electronic Design Automation (EDA), the theory and method of digital system design have developed correspondingly。 VHDL can be used to describe, simulate and design digital system automatically。 Nowadays, it becomes a key technology in automatic electronic design.。There is a lot of superiority in this description language. The result given in this paper show that VHDL is one of the strongest tools in hardware description and it is a flexible among the design method。 The method given in this paper can reduce the difficulty of digital system design and improve the work efficiency.。At present, it is the first class in the world that the design of digital system and single chip system using CPLD/FPGA。