Low power operation method for apparatus having data transmission rate

A low power operation method for an apparatus having a data transmission rate,

• wherein the method is applied with a main apparatus, which comprises a first frequency oscillator (high-frequency oscillator, HOSC), a second frequency oscillator (low-frequency oscillator, LOSC), a power management unit (PMU), a timer, and a regulator;
• and
• wherein the method comprises steps of:
• (a) obtaining a base frequency of said main apparatus, wherein said base frequency is a known constant being a ratio of an ideal frequency of said first frequency oscillator to an ideal frequency of said second frequency oscillator;
• (b) turning on said PMU and said first frequency oscillator;
• (c) loading a data transmission rate, which is set by a user, to said timer as an initial timing length;
• then, in said regulator, calculating an actual period of said second frequency oscillator through said first frequency oscillator to obtain an actual frequency ratio, which is shifting, as a real frequency;
• and, at last, through processing calculation with said regulator, multiplying a ratio of said base frequency to said real frequency by said initial timing length to obtain a valid timing length of said timer;
• (d) awaiting said main apparatus to enter into a sleeping mode;
• (e) turning off said PMU and said first frequency oscillator;
• and,
• (f) after said timer processes timing until reaching said valid timing length, turning back to step (b) to process a next cycle of step (b) to step (f) continuously.