Management of data before zero volt suspend in computer power management

• US 6,618,812 B2
• Filed: 03/20/2001
• Issued: 09/09/2003
• Est. Priority Date: 12/16/1994
• Status: Expired due to Fees

• Current Assignee: PDACO LIMITED
• Original Assignee: Elonex IP Holdings Limited
• Inventors: Seiler, William J., Kikinis, Dan
• Primary Examiner(s): Jean, Frantz B.
• Application Number:
  US09/814,007
• Publication Number:
  US 20010032291A1
• Time in Patent Office: 903 Days
• Field of Search: 713/300-340
• US Class Current: 713/300
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 9/4418 Suspend and resume; Hibernate and awake

Abstract

A power management system for computers compresses contents of system RAM and stores the contents on a non-volatile storage device before power is suspended to a motherboard, which removes power also from RAM. By compression, the capacity required of the non-volatile storage device is minimized. In a variation, zeros are stored in all RAM area used by memory management software before compression and storage on the non-volatile device. In another variation, areas of RAM used by memory management software are identified, and only those areas not used by memory management software are stored on the non-volatile device. The capability is provided in several ways in different embodiments.

Claims

1. A method of power management in a computing device having volatile RAM and non-volatile memory, a power supply and a plurality of input devices, comprising:

providing power to said volatile RAM, non-volatile memory and said input devices;

monitoring said input devices for a predetermined period of inactivity;

saving data stored in said volatile RAM to said non-volatile memory in response to said predetermined period of inactivity elapsing, including the step of reclaiming system memory areas of said volatile RAM by writing zeros to said system memory areas prior to storing said data in said non-volatile memory;

thereafter, removing power to said volatile RAM and said non-volatile memory; and

monitoring said input devices for subsequent activity.

2. The method of power management as recited in claim 1, further comprising:

applying power to said volatile RAM and said non-volatile memory upon detection of subsequent activity in said input devices; and

restoring said data from said non-volatile memory to said volatile RAM.

3. The method of power management as recited in claim 1, wherein said step of saving data stored in said volatile RAM to said non-volatile memory further comprises:

compressing said data prior to writing said data to said non-volatile memory.

4. The method of power management as recited in claim 3, further comprising:

applying power to said volatile RAM and said non-volatile memory upon detection of activity in said input devices;

decompressing said data in said non-volatile memory; and

writing said data from said non-volatile memory to said volatile RAM.

5. A computing apparatus having power management, comprising:

a BIOS containing instructions for controlling the computing apparatus and managing power consumption;

a power supply;

a non-volatile memory device;

at least one input device;

a central processing unit;

a random access memory,

wherein contents of the random access memory are saved to the non-volatile memory device after a predetermined period of inactivity elapses at said at least one input device, system memory areas of said random access memory are reclaimed by writing zeros to said system memory areas prior to storing said data in said non-volatile memory, and thereafter power is removed from random access memory and maintained with respect to said at least one input device.

6. The apparatus of claim 5, wherein power is applied to said random access memory upon detection of activity in said at least one input device and wherein the contents of said random access memory are restored from said non-volatile memory.

7. The apparatus of claim 5, wherein the contents of said random access memory are compressed prior to being saved in said non-volatile memory.

8. The apparatus of claim 7, wherein power is applied to said random access memory and said non-volatile memory device upon detection of activity in said at least one input device, and wherein the contents of said non-volatile memory are decompressed and written to said random access memory.

9. The apparatus of claim 5, wherein said at least one input device comprises one of a keyboard, a mouse, a pointer and a ring indicator.

10. A method of reducing power consumed by a computing device having a power supply, volatile RAM, non-volatile memory, and input devices, the computing device having a power management routine loaded from a BIOS into the volatile RAM upon startup or reset of the computing device, comprising:

executing the power management routine to monitor the input devices for input activity;

determining if a predetermined period of time has elapsed since a last monitored activity on all user input devices;

moving data stored in said volatile RAM to non-volatile memory after the predetermined period of time has elapsed, including the step of reclaiming system memory areas of said volatile RAM by writing zeros to said system memory areas prior to storing said data in said non-volatile memory;

instructing the power supply to cease providing power to predetermined components within the computing device with the exception of the input devices;

monitoring said input devices for subsequent activity;

applying power to said predetermined components upon detection of subsequent activity in said input devices; and

restoring said data from said non-volatile memory to said volatile RAM.

11. The method of reducing power consumed by a computing device as recited in claim 10, wherein said step of moving data stored in volatile RAM further comprises compressing said data prior to writing said data to said non-volatile memory.

12. The method of reducing power consumed by a computing device as recited in claim 11, wherein said step of restoring said data from said non-volatile RAM comprises decompressing said data in said non-volatile memory.