Computer power management system

A power system for a computer system having a processor, the processor operating at at least two clock frequencies, each clock frequency being associated with a particular supply voltage level for clocking the processor, comprising:

• a supply voltage circuit for generating at least two different supply voltage levels for clocking the processor, a first supply voltage level being less than the second supply voltage level;
• means for determining a duration of elapsed time the processor has been operating at a first clock frequency associated with the first supply voltage level;
• and
• means for controlling the supply voltage circuit to supply the second supply voltage level for clocking the processor in place of the first supply voltage level when the duration of elapsed time exceeds a predetermined amount, the processor thereby operating at a second clock frequency associated with the second supply voltage level, and wherein the second clock frequency is higher than the first clock frequency.

A method for reducing power consumed by a computer having a processor for executing at least one user application program and having a manual input device for inputting data to the processor, the application program generating processor interrupts for receiving data at the processor from the manual input device, comprising the steps of:

• executing the application program at a first operating frequency of the processor;
• during the execution of the application program, counting a first number of the processor interrupts generated by the application program during a first time interval of predetermined duration;
• then counting a second number of the processor interrupts generated by the application program during a second time interval of equal duration and subsequent to the first;
• if the first number is within a predetermined value of the second number, then determining if the processor is executing a predetermined activity;
• and
• if the processor is executing the predetermined activity, then operating the processor to continue executing the application program but at a second operating frequency lower than the first operating frequency.

A method of operating a computer having a display device, a manual input device, and a processor, the processor operating at at least two clock signal frequencies, comprising the steps of:

• stopping the processor by stopping supply of a clock signal to the processor, while maintaining power to the display device and to the manual input device;
• then, resuming operation of the processor by supplying a lower of the two clock signal frequencies to the processor;
• determining a duration of elapsed time that the processor has been operating at the lower of the two clock signal frequencies;
• and
• then, supplying the higher of the two clock signal frequencies to the processor in place of the lower of the two clock signal frequencies if the elapsed time exceeds a predetermined value.

A power supply system for a computer system having a display device and a manual input device connected to a processor, the processor operating at at least two clock signal frequencies, comprising:

• means for stopping supply of a clock signal to the processor while maintaining power to the display device and manual input device, thereby stopping the processor;
• means for supplying a lower of the two clock signal frequencies to the processor, thereby resuming operation of the processor;
• means for determining a duration of elapsed time that the processor has been operating at the lower of the two clock signal frequencies;
• and
• means for supplying the higher of the two clock signal frequencies to the processor in place of the lower of the two clock signal frequencies if the duration of elapsed time exceeds a predetermined value.