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US4618953A Expired / Lapsed US ⏱️ 0.0 years remaining

Watchdog circuit

Assignee: Pitney Bowes Inc
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Filing: 1984-05-01
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Granted: 1986-10-21
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Expires: 2004-05-01
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Abstract

Abstract A watchdog circuit for improving the possibility of recovery from failures, such as those caused by static discharge or RF interference, in a data processing system. A data processing system includes a main, multi-chip processor for handling the main computational burden and a single-chip processor for handling I/O functions. Additionally, the main processor periodically sends status to the single-chip processor. If the single-chip processor does not receive status within a predetermined period it generates a reset signal to the main processor. In response to the reset signal the main processor interrogates the single-chip processor to determine if the reset was caused by a failure or a power-on condition. Because of its self contained construction the single-chip processor is less susceptible to static induced failures and will improve the recovery capabilities of the system when used to monitor the main processor.

Inventors

  • 👤 Edward P. Daniels
  • 👤 Risto A. Rinne, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 20:05
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0703; G06F11/0751; G06F11/0754; G06F11/0757; G06F11/14; G06F11/0796; G06F15/00; G06F15/16

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 109 words
A data processing system comprising: (a) a main, multi-chip processor; (b) a single-chip processor operatively associated with said main processor, said main processor transmitting and said single-chip processor receiving status information; (c) reset means, controlled by said single-chip processor, for resetting said main processor; and, (d) timing means operatively associated with said single-chip processor for measuring the time elapsed between said status receptions by said single-chip processor and for signaling said single-chip processor, said single-chip processor through said reset means resetting said main processor in response to said signal if a predetermined amount of time elapses after one of said status receptions and before the next of said receptions.
Claim 2
Dependent Claim 109 words
A data processing system comprising: (a) a main, multi-chip processor; (b) a single-chip processor operatively associated with said main processor, said main processor transmitting and said single-chip processor receiving status information; (c) reset means, controlled by said single-chip processor, for resetting said main processor; and, (d) timing means operatively associated with said single-chip processor for measuring the time elapsed between said status receptions by said single-chip processor and for signaling said single-chip processor, said single-chip processor through said reset means resetting said main processor in response to said signal if a predetermined amount of time elapses after one of said status receptions and before the next of said receptions.
Claim 3
Dependent Claim 30 words
A data processing system as described in claim 1 wherein said single-chip processor is operatively connected to an input/output device and is programmed to control input/output operations for said systems.
Claim 4
Dependent Claim 75 words
A data processing system as described in claim 1 wherein said main processor is programmed to perform selected operation cycles and is also programmed to periodically transmit status to said single-chip processor at at least the initial point of said operation cycles, so that status is transmitted by said main processor to said single-chip processor at intervals of no more than a predetermine length so long as said main processors program sequence is not disrupted.
Claim 5
Dependent Claim 76 words
A data processing system as described in claim 2 wherein said main processor is programmed to perform selected operations cycles and is also programmed to periodically transmit status to said single-chip processor at at least the initial point of said operations cycles, so that the status is transmitted by said named processor to said single-chip processor at intervals of no more than a predetermined length so long as said main processors program sequence is not disrupted.
Claim 6
Dependent Claim 77 words
A data processing system as described in claim 3 wherein said timing means is a programmable timer which interrupts said single-chip processor upon expiration of said predetermined amount of time and said single-chip processor resets said main processor in response to said interrupt, and wherein further, said single-chip processor resets said timer upon receipt of status from said main processor and said predetermined amount of time is at least equal to said predetermined length of said interval.
Claim 7
Dependent Claim 77 words
A data processing system as described in claim 4 wherein said timing means is a programmable timer which interrupts said single-chip processor upon expiration of said predetermined amount of time and said single-chip processor resets said main processor in response to said interrupt, and wherein further, said single-chip processor resets said timer upon receipt of status from said main processor and said predetermined amount of time is at least equal to said predetermined length of said interval.
Claim 8
Dependent Claim 22 words
A data processing system as described in claim 1 wherein said single-chip processor is hardened to reduce its susceptibility to static discharge.
Claim 9
Dependent Claim 22 words
A data processing system as described in claim 2 wherein said single-chip processor is hardened to reduce its susceptibility to static discharge.
Claim 10
Dependent Claim 22 words
A data processing system as described in claim 3 wherein said single-chip processor is hardened to reduce its susceptibility to static discharge.
Claim 11
Dependent Claim 22 words
A data processing system as described in claim 5 wherein said single-chip processor is hardened to reduce its susceptibility to static discharge.
Claim 12
Dependent Claim 22 words
A data processing system as described in claim 5 wherein said reset means is hardened to reduce its susceptibility to static discharge.
Claim 13
Dependent Claim 22 words
A data processing system as described in claim 9 wherein said reset means is hardened to reduce its susceptibility to static discharge.
Claim 14
Dependent Claim 36 words
A data processing system as described in claim 1 wherein said status transmitted by said main processor includes data to be retrieved by said main processor from the single-chip processor during execution of a recovery routine.
Claim 15
Dependent Claim 37 words
A data processing system as described in claim 2 wherein said status transmitted by said main processor includes data to be retrieved by said main processor from said single-chip processor during the execution of a recovery routine.
Claim 16
Dependent Claim 37 words
A data processing system as described in claim 3 wherein said status transmitted by said main processor includes data to be retrieved by said main processor from said single-chip processor during the execution of a recovery routine.
Claim 17
Independent Claim 74 words
A method of increasing reliability in a data processing system comprising a main multi-chip processor operatively associated with a single-chip processor, comprising the steps of: (a) repeatedly transmitting status from said main multi-chip processor to said single-chip processor within intervals of no more than a predetermined length; and, (b) resetting said main, multi-chip processor in response to a command from said single-chip processor if the interval between said status transmission exceeds said predetermined length.
Claim 18
Independent Claim 74 words
A method of increasing reliability in a data processing system comprising a main multi-chip processor operatively associated with a single-chip processor, comprising the steps of: (a) repeatedly transmitting status from said main multi-chip processor to said single-chip processor within intervals of no more than a predetermined length; and, (b) resetting said main, multi-chip processor in response to a command from said single-chip processor if the interval between said status transmission exceeds said predetermined length.
Claim 19
Dependent Claim 16 words
The method of claim 16 wherein said single-chip processor controlls the input/output operations of said system.

References Cited (Backward Citations)

US3795800A Cited
US4072852A Cited
US4300199A Cited
US4488303A Cited
US4551841A Cited
US4538273A Cited
US4513417A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-10-20 1990-04-21 1990-10-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-10-20 1994-04-21 1994-10-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-10-20 1998-04-21 1998-10-21 $7700.00 Window Closed / Lapsed

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