【正文】 t is similar to the energy storage device with the inductor or capacitor circuit, such as flipflops, latches, counters, shift register, memory circuits, and so are the typical timing circuit devices.Digital circuit characteristics:1. At the same time with arithmetic operations and functions of logic operationDigital logic circuits based on binary math to algebra basis for the use of binary digital, not only for arithmetic operations and can easily carry out logic operations (and, or, nonjudge, pared to deal with, and so on) and therefore extremely suitable for operations, pared with, storage, transmission, control, decisionmaking applications.2. Simple, reliable systemOn the basic of binary digital logic circuits, simple and reliable, highaccyracy.3. Hight integratrd, feature easy to avhieveHigh integration, small size, lowpower digital circuit is one of the outstanding design, repair and maintainflexibility, with the development of highspeedin tegratedcircuit techonlogy, digital logic circuits of tegrated circuit technology, digital logic of chips as smallscale integration, the functions of chips as smallscale integarted circuits(SSI), inscale integarated circuits(MSI),largescaleintedcircuits(LSI), ultralargescaleintegrated circuits (VLSI) from the development of the ponment level, the device level, ponent level, board level to systemlevel rise. Componment level, board level to sytemlevel rise. Circuit posed of just using standard cell chios connected. For the special nonstandard circuit can also use programmable logic array circuit thtough the programming of arbitrary logic function.Application of digital circuit:Digital circuits and digital and digital electronic technology usedinawiderange of television, radar, munications, puter, automation, space science and technology in various fields.The development of integrated circuits:From thebeginning of the 1960s, the development of the integrated circuit has gone through smallscale, medium scale and largescale and ultralargescale stage of development, is now an even large scale, the development of integrated circuits will reach more than 10, each the equivalent of 10 chip ponents, cirucit design rules will be reduced to . 60 to 70 years, is the focus of the technical maturity of the integrated circuit.. From 1970 to 1985, technology development center is the microprocessor and memory. Research in 1985 after the application specific integrated circuit is hot. Into the largescale integratedcircuits, design and technological progress, especially in the development of puteraided design plays an increasingly important 1985, the first piece of integrated circuits e out, in 1960 the first batch of integrated circuits in the United States.This is a smallscale integrated circuits. As the process conditions, the begining of the integrated circuit are mixed, that is a bonation of technology and integrated electronic ponents separation process. The first integrated circuit puter taining 587 integrated the impovement of the integrated circuit technology and development of the integrated circuit in 1964 the price had been below the separation of ponents fo the price of equivalent integrated puter era has finally e. 60 to the end, the United States the development of integrated circuits can be used to create a dedicated puter. In 1969 the pany made autmated omboard puter prototype of the D200, its central processing unit by 24 largescale integrated circuits made, each piece contains transistors 1421050. To the 70S, could have been a puter’s central processing ponents integrated into a silicon chip, the birth of the integration of microprocessors and microprcessor. It not only brings to the industry change, has affected the whole of human life. In 1977, VLSI Techology Breakthroughs have been made, on a silicon chip can acmodate more than 10,000 transistors, 16K and 64Kbit memory produced. In 1985the pany introduced the Intel 80386 microprocessor, integarated.Reached 270,000 transistors. To the 90’s, multichip integrated way in the United States to solve the probiem of the scale integrated circuits provide significant benefits.附錄