Patent ID: 7065664

Claim:
A method for achieving power management of a PDA containing a CPU for processing data, a microprocessor for supervising a power system of the PDA, and a display module for displaying the data, the method comprising: (a) switching the PDA from OFF mode to SHUTDOWN mode, wherein when the PDA is in OFF mode, the CPU, the microprocessor, and the display are all off, and when the PDA is in SHUTDOWN mode, the CPU and the display module are off while the microprocessor is on; (b) after step (a), switching the PDA from SHUTDOWN mode to ON mode, wherein when the PDA is in ON mode, the CPU, the microprocessor, and the display module are all on; (c) after step (b), switching the PDA between ON mode and SCREEN TOGGLE mode, wherein when the PDA is in SCREEN TOGGLE mode, the CPU and the microprocessor are on while the display module is off; and (d) after step (b), switching the PDA between ON mode and STANDBY mode, wherein when the PDA is in STANDBY mode, the CPU is idle, the microprocessor sleeps, and the display module is off, and an operating current of the CPU when the CPU is idle is smaller than the operating current when the CPU is on, and an operating current of the microprocessor when the microprocessor sleeps is smaller than the operating current when the microprocessor is on.