VLSI Very Large Scale Integrated Circuit is a combination of a large number of transistors to a single integrated circuit chip, which is larger than the degree of LSI integration. The number of transistors integrated different in different standards. Starting in the 1970s, with the development of complex semiconductor and communication technology, integrated research, development has gradually expanded. The computer control core microprocessor is the most typical examples of ultra large scale integrated circuit, VLSI Design, especially digital integrated circuits, electronic design automation usually the way, has become an important branch of computer engineering one.
IC according to the level of integration can be divided into small-scale integrated circuits, the size of integrated circuits, LSI, VLSI, VLSI and huge integrated circuits.
Small-scale integrated circuit in 1960 appeared on a silicon wafer containing 10-100 1-10 element or logic gates. Such as logic gates and flip-flops and so on. If small-scale digital integrated circuits (SSI) design combinational logic circuit, it is the gate as the basic unit of the circuit, so simplifying logic function of the number of gates should be used at least, and also the number of inputs of the gate at least.
