Patent · US Expired

Software-based voltage detection to reserve device power upon shutdown

USRE40236E1 · kind E1 · reissue

3Cited by
25References
40Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 27, 2005
Grant dateApr 8, 2008
Priority date
Expiry dateMay 27, 2025

Classification

  • Technology area (CPC —)General

Abstract

Methods and apparatus are provided for reserving power in a handheld computer by inducing a sleep mode when the energy supply of the handheld computer reaches a predetermined low level. A software is provided which operates a sleep mode when a device of the handheld computer detects a predetermined low battery voltage. A processor operates the software to place the handheld computer in a low energy-consuming shutdown state in which an interrupt controller operates to mask those interrupt signals thus providing an user with the impression that the device has entered an unresponsive sleep mode. In maintaining the sleep mode, the processor operates such that all input signals that request the handheld computer to power up remain active but so long as the battery voltage remains below a predetermined voltage the interrupt signals to power up selected applications and devices are masked. A method for returning the handheld computer to its normal operational mode once the energy supply has been replenished, is also provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.