Methods for controlling a main clock source shared between different wireless communications modules and apparatuses using the same

A method executed by a first wireless communications module for controlling a clock source shared with at least a second wireless communications module comprising:

• detecting a request from the second wireless communications module for activating the clock source;
• determining whether a reference clock has been stably generated by the clock source;
• and
• avoiding adjusting an electrical characteristic of the clock source when the reference clock has been stably generated, wherein an adjustment to the electrical characteristic of the clock source facilitates the reference clock output from the clock source to achieve a target frequency.

A communications apparatus, comprising:

• a clock source providing a reference clock;
• a first wireless communications module comprising:
• an interface;
• and
• a micro controller unit coupled to the interface;
• and
• a second wireless communications module notifying the first wireless communications module that the clock source has been requested for activating via the interface of the first wireless communications module,
• wherein the micro controller unit detects the reference clock, determines whether to adjust an electrical characteristic of the clock source to facilitate the reference clock to achieve a target frequency with reference to the detected reference clock after receiving the notification from the second wireless communications module, and adjusts the electrical characteristic of the clock source in terms of the determination.