System and method of controlling power consumption by dynamically controlling brightness of display with inversely proportional to operating frequency of CPU

Abstract

A power control unit for a battery-driven data processing system, in which the power consumption of the whole system is prevented from increasing by controlling the clock frequency of a CPU and the brightness of a display unit, is disclosed. When the clock frequency of the CPU is increased, the brightness of the display unit connected to the data processing system having the CPU built therein is decreased while, when the clock frequency of the CPU is reduced, the brightness of the display unit is increased thereby to maintain a substantially constant power consumption. In the case where the brightness of the display unit connected to the data processing system is increased, on the other hand, the clock frequency of the CPU is reduced, while in the case where the brightness of the display unit is reduced, the clock frequency of the CPU is increased thereby to maintain a substantially constant power consumption. Further, the clock frequency of the CPU is reduced at the time of spinup of the drive motor for a disk-shaped recording medium, and at the end of the spinup operation, the clock frequency of the CPU can be restored to the original state.

Dependencies are inferred from the claim text.