It is a 6-inverter, which shapes, isolates and improves the load capacity, that is, it provides high resistance to the input pin, so that the rising time of the signal (the steepness of the rising edge) is not affected by the internal circuit.

The integrated circuit chip of single chip microcomputer is a small and perfect microcomputer system which integrates the functions of CPU RAM, ROM, various I/O ports, interrupt system, timer/timer (possibly including display drive circuit, pulse width modulation circuit, analog multiplexer, A/D converter, etc.). Using VLSI technology, the chip with data processing ability is integrated into a silicon chip, which is widely used in industrial control field.