DISTRIBUTED SYNCHRONIZATION AND TIMING SYSTEM

摘要

An apparatus for generating a local clock signal, comprising: a USB adapted to receive a USB data stream; a reference signal source for providing a reference signal; timing circuitry for determining a frequency of a periodic data structure decoded from the USB data stream by comparing the periodic data structure with the reference signal; and circuitry for generating a local clock signal having a desired local clock frequency. The circuitry for generating the local clock signal is configured to receive an information signal having data indicative of the desired local clock frequency and to generate the local clock signal by: i) generating a clock synchronization signal comprising clock and trigger signals by combining the periodic data structure with a scaling factor; ii) generating a divided signal by dividing the reference signal; iii) manipulating the clock synchronization signal and the divided signal according to the desired local clock frequency; iv) generating a phase comparison signal by phase comparing the manipulated clock synchronization signal and divided signal; and v) generating the local clock signal with a controlled oscillator clock generator of the circuitry by using the phase comparison signal to control the controlled oscillator clock generator.