当今社会是数字化的社会，是数字集成电路广泛应用的社会，数字集成电路本身在不断地进行更新换代。它由早期的电子管、晶体管、小中规模集成电路，发展到超大规模集成电路(VLSIC，几万门以上)以及许多具有特定功能的专用集电路。但是，随着微电子技术的发展，设计与制造集成电路的任务己不完全由半导体厂商来独立承担。系统设计师们更愿意自己设计专用集成电路(ASIC)芯片-Today' s society is a digital society, it is widely used in digital integrated circuits community, digital integrated circuits were constantly upgrading itself. It consists of the early vacuum tubes, transistors, small-scale integrated circuit, the development of ultra large scale integrated circuit (VLSIC, tens of thousands over the door) and many special features with a specific set of circuits. However, with the development of microelectronics technology, the task of design and manufacture of integrated circuits, semiconductor manufacturers have not fully come to independently. System designers are more willing to design their own application specific integrated circuit (ASIC) chip