摘要 |
A phase-locked loop circuit ("PLL") is adjustable in both phase and frequency. By providing a plurality of taps on the voltage-controlled oscillator of the PLL, and providing separate multiplexers, each of which can select a different tap-one for the PLL feedback loop and one for the PLL output-one allows the user to adjust the phase of the output relative to that of the input. Similarly, by providing loadable pre-scale (divide by N), post-scale (divide by K) and feedback-scale (divide by M) counters, one allows the user to adjust the frequency of the output to be M/(NK) times that of the input.
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