It is shown how to connect a quartz crystal to the microcontroller and adjust the fuses of the microcontroller ATmega8. A quartz resonator is a kind of frequency generator. Although many MCs, including ATmega8, have a builtin generator, or rather an RCchain, and can do without external quartz. For many tasks such a solution is completely justified, but once the MC is used to accurately count the time or to form a given time interval various measuring devices, a quartz crystal should be applied without fail. Because it has more accuracy than the internal generator of the MC.
In order for the microcontroller to work from a quartz crystal, it is necessary to configure fusions, which are also called protection bits, although the latter is not entirely correct. How to perform the specified actions is shown in this video.