Reliable watchdog timer

Details Reliable watchdog timer Reliable watchdog timer

1991-06-26

1993-08-03

Rudolph, Rebecca L.

Excavating

395575, 364DIG1, 364264, 364265, 364270, G06F 1100

Patent

active

052336131

ABSTRACT:
In a watchdog timer, the selected codes identifying the format of a watchdog timer algorithm, such as the intervals within which a watchdog timer status must be issued by the host processor, are supplied as hardwired preset codes in programmable fuse or read only memory cells that are adapted to be programmed, but are immune from ESD, power glitches and errant software. A programmable code indicating a programmable time interval is also stored in a register protected from errant software when the watchdog timer is enabled. A selector receives the preset code and the programmable code and selects an output code indicating the time interval within which the watchdog timer must be reset by a processor status signal. The selector can be programmed to select only the preset code by supplying a selector control signal through an element that is immune from electrostatic discharge, power glitches and errant software. Also, a code fixing the watchdog timer in an on state can be supplied with ESD-immune cells. The watchdog timer employs a keyed sequence for the watchdog timer status signal.

REFERENCES:
patent: 3878370 (1975-04-01), Santomango et al.
patent: 3919533 (1975-11-01), Einolf, Jr. et al.
patent: 4161649 (1979-07-01), Klos et al.
patent: 4410938 (1983-10-01), Higashiyama
patent: 4538273 (1985-08-01), Lasser
patent: 4566111 (1986-01-01), Tanagawa
patent: 4597052 (1986-06-01), Matsuda
patent: 4618953 (1986-10-01), Daniels et al.
patent: 4636967 (1987-01-01), Bhatt et al.
patent: 4705970 (1987-11-01), Turnpaugh
patent: 4727549 (1988-02-01), Tulpule et al.
patent: 4796211 (1989-01-01), Yokouchi et al.
patent: 4912708 (1990-03-01), Wendt
Computer Architecture and Organization by John P. Hayes, McGraw-Hill, 1978, pp. 271-295.

Affiliated with

Also associated with

Rating

Reliable watchdog timer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Reliable watchdog timer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reliable watchdog timer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2277804