Fast-locking phase-locked loop, frequency divider, and communication device

A fast-locking phase-locked loop, comprising a phase frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, a fast-locking control unit and a frequency divider,

• wherein the fast-locking control unit is configured to output a reset signal at a high level in response to a rising edge of a reference clock signal when receiving a phase-locking enable signal;
• the frequency divider comprises a plurality of cascaded frequency division units and a reset/set control circuit, the reset/set control circuit being configured to receive the reset signal outputted by the fast-locking control unit, and in response to transition of the reset signal from a low level to the high level, change a state code combination composed of respective state codes of the cascaded frequency division units from a first state to a second state, to cause transition of a feedback signal outputted by the frequency divider from the low level to the high level;
• and
• the phase frequency detector is configured to output a phase error between the reference clock signal and the feedback signal in response to the reset signal at the high level.