Real-time power conservation for portable computers
First Claim
1. A method for real-time power conservation in a computer, comprising the steps of:
- (a) determining whether a central processing unit (CPU) in a computer is available for power conservation;
(b) if said CPU is available for power conservation, determining a current clock rate for said CPU;
(c) saving a value equal to said determined current clock rate;
(d) indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;
(e) determining whether an interrupt has occurred;
(f) if an interrupt has not occurred, repeating step (f) wherein said CPU remains in said power conservation mode until an interrupt has occurred;
(g) if an interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU;
(h) retrieving said saved value equal to said determined current clock rate; and
(i) setting said current clock rate equal to said retrieved value.
2 Assignments
0 Petitions
Accused Products
Abstract
A real-time power conservation apparatus and method for portable computers employs a monitor to determine whether a CPU may rest based upon a real-time sampling of the CPU activity level and to activate a hardware selector to carry out the monitor'"'"'s determination. If the monitor determines the CPU may rest, the hardware selector reduces CPU clock time; if the CPU is to be active, the hardware selector returns the CPU to its previous high speed clock level. Switching back into full operation from its rest state occurs without a user having to request it and without any delay in the operation of the computer while waiting for the computer to return to a "ready" state. Furthermore, the monitor adjusts the performance level of the computer to manage power conservation in response to the real-time sampling of CPU activity. Such adjustments are accomplished within the CPU cycles and do not affect the user'"'"'s perception of performance and do not affect any system application software executing on the computer.
365 Citations
15 Claims
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1. A method for real-time power conservation in a computer, comprising the steps of:
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(a) determining whether a central processing unit (CPU) in a computer is available for power conservation; (b) if said CPU is available for power conservation, determining a current clock rate for said CPU; (c) saving a value equal to said determined current clock rate; (d) indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU; (e) determining whether an interrupt has occurred; (f) if an interrupt has not occurred, repeating step (f) wherein said CPU remains in said power conservation mode until an interrupt has occurred; (g) if an interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU; (h) retrieving said saved value equal to said determined current clock rate; and (i) setting said current clock rate equal to said retrieved value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for power conservation in a computer bearing a central processing unit (CPU), said apparatus comprising:
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a CPU activity detector; a CPU clock; a first oscillator for providing pulses at a first speed; a second oscillator for providing pulses at a second speed; a hardware selector for choosing between said first oscillator and said second oscillator, wherein said hardware selector is adapted to receive said pulses from said first oscillator if said first oscillator is chosen or said pulses from said second oscillator if said second oscillator is chosen, wherein said hardware selector is further adapted to forward appropriate pulses from whichever oscillator is chosen by said hardware selector to said CPU clock; a CPU sleep manager adapted to receive detected CPU activity from said CPU activity detector, further adapted to generate a pulse to said hardware selector thereby designating which oscillator said hardware selector should choose. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification