A clock generator is a circuit that produces a timing signal (known as a clock and behaves as such) for use in synchronizing a circuit's operation. It can range from a simple symmetrical square wave to more complex arrangements. The basic parts that all clock generators share are a resonant circuit and an amplifier.
The resonant circuit is usually a quartz piezo-electric oscillator, although simpler tank circuits and even RC circuits may be used.
The amplifier circuit usually inverts the signal from the oscillator and feeds a portion back into the oscillator to maintain oscillation.
The generator may have additional sections to modify the basic signal. The 8088 for instance, used a 2/3rds duty cycle clock, which required the clock generator to incorporate logic to convert the 50/50 duty cycle which is typical of raw oscillators.
