Browse Prior Art Database

Low Power Suspend System for Notebook PC

IP.com Disclosure Number: IPCOM000112633D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Hirata, N: AUTHOR [+3]

Abstract

This article describes an optimized suspend system for notebook Personal Computers (PCs). This system can reduce the power consumption during the suspend state by transferring the data in the video memory to the main memory. In this case, the power for the video memory can be stopped during the suspend state.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Low Power Suspend System for Notebook PC

      This article describes an optimized suspend system for notebook
Personal Computers (PCs).  This system can reduce the power
consumption during the suspend state by transferring the data in the
video memory to the main memory.  In this case, the power for the
video memory can be stopped during the suspend state.

      Normally, power is supplied to the main memory and video memory
to keep the data during the suspend state of a notebook PC.  The
Figure shows the flowchart for this system.  When the suspend command
comes, the data in the video memory is transferred to the main
memory.  At this time, the system keeps enough area in the main
memory to receive the video data.  When this system transfers the
video data to the main memory, the data is compressed to minimize the
area to be kept in the main memory.  Then, the system turns off the
power supply to all components except the main memory and the
refreshing circuit of this memory.  To quit the suspend state, after
resume command, the system turns on the power for all components, and
decompresses and transfers the video data in the main memory to the
video memory.  After that, it resumes to the normal operation mode.

      This system can achieve low power consumption during the
suspended state by the software without any hardware change.  If the
computer has a 512kB-video memory and 4MB main memory, this system
reduces the power consumption during the s...