Crystal Oscillator

It can be used as UART clock (6×1.8432 MHz). It allows integer division to common baud rates (96×115200 baud or 96×96×1,200 baud). It is a common clock for Intel 8051 microprocessors It uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. This frequency is commonly used to keep track of time, to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers. The most common type of piezoelectric resonator used is the quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators.