Clock generator
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A clock generator is an electronic oscillator that produces a clock signal for use in synchronizing a circuit's operation. The signal 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
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 example, used a 2/3 duty cycle clock, which required the clock generator to incorporate logic to convert the 50/50 duty cycle which is typical of raw oscillators.
Other such optional sections include
The clock generator in a motherboard is often changed by computer enthusiasts to control the speed of a CPU, FSB, GPU or RAM. Typically the programmable clock generator is set by the BIOS at boot time to the selected value; although some systems have dynamic frequency scaling, which frequently re-programs the clock generator.
Timing-signal generators (TSGs)
TSGs are clocks that are used throughout service-provider networks, frequently as the building integrated timing supply (BITS) for a central office.[citation needed]
A TSG is clock equipment that accepts input timing reference signals and generates output timing reference signals. The input reference signals can be either DS1 or composite-clock (CC) signals, and the output signals can also be DS1 or CC signals (or both). A TSG is made up of the six components listed below:[citation needed]
- An input timing interface that accepts DS1 or CC input signals
- A timing-generation component that creates the timing signals used by the output timing-distribution component
- An output timing distribution component that utilizes the timing signals from the timing-generation component to create multiple DS1 and CC output signals
- A performance-monitoring (PM) component that monitors the timing characteristics of the input signals
- An alarm interface that connects to the central-office (CO) alarm-monitoring system
- An operations interface for local crafts person use and communications with remote operations systems
See also
- Pulse generator – A pulse signal generating circuit