Computer system with video display controller having power saving modes

A method of operating a computer system having an input device for receiving an input from a user, a central processing unit (CPU) responding to said user input to perform a processing function producing an output response, and an output device responding to said output response of said CPU to provide an externally perceivable response to the user, said output device including a display device providing a visible image in response to said output response of said CPU, said method including steps of:

• providing said computer system with a video display controller (VDC) interfacing with said CPU, having a plurality of functions, and providing driving signals to said display device;
• providing said VDC with a power saving controller, and configuring said power saving controller to include a register having multiple, independently addressable register levels, at least two of said register levels defining at least two externally programmable power saving modes respectively, at least a remaining one of said register levels defining a hardware-activated power saving mode, providing for each of said plurality of power saving modes to control selected ones of said plurality of functions of said VDC, and enabling or disabling each of said plurality of functions individually when a current one of said power saving modes is selected according to a predetermined mode hierarchy and external input comprising at least one of user input received from said input device and a hardware state change depending on the contents of said register.

A power saving system for a computer capable of performing a plurality of power-consuming operating functions, comprising:

• input means for receiving input signals designating multiple independently addressable power saving modes, at least two of said power saving modes being externally programmable and at least a remaining one of said power saving modes being selectable through hardware, said power saving modes being activated according to a predetermined mode hierarchy and a received input signal comprising at least one of user input and a hardware state change, each of said power saving modes specifying power levels for said operating functions;
• storage means for storing each of said power saving modes;
• and
• control means responsive to the input means for reading one of said power saving modes from the storage means designated by the received input signal, and controlling the computer to operate with said operating functions at said power levels corresponding to said designated power saving mode.

A method of reducing power consumption in a computer capable of performing a plurality of power-consuming operating functions, comprising the steps of:

• (a) receiving input signals designating multiple independently addressable power saving modes, at least two of said power saving modes being externally programmable and at least a remaining one of said power saving modes being selectable through hardware, said power saving modes being activated according to a predetermined hierarchy and a received input signal comprising at least one of user input and a hardware state change, each of said power saving modes specifying power levels for said operating functions;
• (b) storing each of said power saving modes;
• (c) reading one of said power saving modes from the storage means designated by the received input signal;
• and
• (d) controlling the computer to operate with said operating functions at said power levels corresponding to said designated power saving mode.

A display controller that provides driving signals for a display apparatus, said display controller comprising:

• a power saving controller, said power saving controller comprising:
• a register having multiple, independently addressable register levels,
• at least two of said register levels defining at least two externally programmable power saving modes respectively,
• at least a remaining one of said register levels defining a hardware-activated power saving mode,
• each of said power saving modes controlling a plurality of power-consuming functions of said display controller, and wherein
• each of said plurality of power-consuming functions of said display controller are individually enabled or disabled when a current one of said power saving modes is selected according to a predetermined mode hierarchy and an external input comprising at least one of a user input received from an input device and a hardware state change depending on the contents of said register.