vcc has two meanings, one is the power supply voltage of the circuit, and the other is the virtual call center. Vcc is short for VoltCurrentCondenser, which means the supply voltage of the circuit. It is the first industrial system level designed for IP multiplexing.

VDD is the working voltage of the chip: VCCC=circuit indicates the meaning of the circuit, that is, the voltage connected to the circuit, and D=device indicates the meaning of the device, that is, the working voltage inside the device. In ordinary electronic circuits, generally VCC >; Vdd。