Power on timer for a personal computer system
US5557784A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1995 |
| Grant date | Sep 17, 1996 |
| Priority date | — |
| Expiry date | Mar 30, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/88
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This disclosure relates to a method and apparatus for measuring the amount of time a personal computer system is powered on. A power on time (POT) routine is performed at a power on of the computer system. This routine sets up a timer to count the number of pre-selected time units (selected by a user) the system is powered on. The power on time count is stored in the PC's non-volatile memory. The routine sets an alarm field of the system's real time clock (RTC) to be activated after the pre-selected time unit has elapsed. A POT interrupt handler routine is installed in a chain for RTC interrupts and is invoked each time the alarm is activated (i.e., at each passage of the pre-selected time unit) while the system is powered on. When invoked, the POT interrupt handler routine increments the POT count and resets the RTC alarm to be activated after another pre-selected time unit has elapsed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.