Power saving control system for computer system with feature of selective initiation of power saving control

Abstract

A power saving control system for a computer system including a CPU, comprises a mode selecting circuit for selectively operating the CPU in a normal mode with relatively high performance and high power consumption and a power saving mode with relatively low performance and low power consumption, a first monitoring circuit for monitoring addresses accessed by the CPU over a first given period in order to detect a predetermined operational state of the CPU, in which only specific address group is repeatedly accessed, a second monitoring circuit for monitoring addresses accessed by the CPU over a second given period in order to detect a predetermined operational state of the CPU, in which only specific address group is repeatedly accessed, the second given period being independent of the first given period and much longer than the first given period, and a controller associated with the mode selecting circuit for normally operating the mode selecting circuit in the normal mode and responsive to one of the first and second monitoring circuit detecting the predetermined operational state, for operating the mode selecting circuit in the power saving mode as long as the predetermined operational state is maintained.

Dependencies are inferred from the claim text.