A digital integrated circuit is a digital logic circuit or system made by integrating components and connections on the same semiconductor chip. According to the number of gate circuits or components contained in digital integrated circuits, digital integrated circuits can be divided into small scale integration (SSI) circuits, medium scale integration (MSI) circuits, large scale integration (LSI) circuits, and very large scale integration (VLSI) circuits. ) circuits and Very Large Scale Integration (ULSI) circuits. The small-scale integrated circuit contains less than 10 gate circuits, or the number of components does not exceed 100; the medium-scale integrated circuit contains between 10-100 gate circuits, or the number of components is between 100-1000; Large-scale integrated circuits contain more than 100 gate circuits, or the number of components is more than 1,000; very large-scale integrated circuits contain more than 10,000 gate circuits; VLSI contains more than 100,000 gate circuits. It includes: basic logic gates, flip-flops, registers, decoders, drivers, counters, shaping circuits, programmable logic devices, microprocessors, microcontrollers, DSPs, etc.