Clock generators are integrated circuits (ICs) that generate multiple output frequencies from a single input reference frequency. The input or reference frequency is supplied by a crystal, XO or other clock in the system. Clock generators may have other features that can be controlled by I2C or pins such as: turning on/off outputs, skewing frequencies, and adding/removing spread spectrum to frequencies to reduce noise. The perceived challenge with clock generators is system layout. Placing a crystal adjacent to its target IC is simple and cheap. Routing a clock signal from a clock generator to its target IC might not always be as easy, although it can save money. Careful design and other techniques can ensure a centralized clock source provides equal performance. Generally speaking, if four or more clocks are required designers can save money with a clock generator.