Phase-locked loop (PLL) methods and apparatus are described for generating
multiple output clocks synchronized to different frequencies of multiple
input signals, wherein the multiple-output PLL employs a single voltage
controlled oscillator (VCO). In an embodiment, the base module generates
signals with a controlled frequency, multiple equidistant phase, and
reduced duty cycles. Frequency dividers using barrel-shifters driven by
an early-late detector combined with a left/right "one hot"
shift-register or driven by an early-late detector combined with up-down
counter/decoder are also disclosed.