# US 5,345,583 A · Method and apparatus for momentarily interrupting power to a microprocessor to clear a fault state > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,583 A - Document ID: US5345583A - Status: Granted - Kind: A - Application number: 08/043,440 - Filed: 1993-04-05 - Granted: 1994-09-06 - Earliest claimed: 1992-05-13 - Assignees: Scientific-Atlanta, Inc. - Inventors: Glenn A. Davis - Web page: https://patentgrep.com/patent/US5345583A ## CPC - G06F 11/1441: {Resetting or repowering} - G06F 11/0757: {by exceeding a time limit, i.e. time-out, e.g. watchdogs} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method and apparatus for providing notice of impending initialization prior to initializing a microprocessor to enable the microprocessor to store operating data prior to initialization and to use the stored operating data after initialization. The apparatus includes a notice device for supplying a notice signal to warn the microprocessor of an impending initialization and an interrupt device for supplying an interrupt signal to cause a switching device to momentarily interrupt electrical power to the microprocessor. The cycling of microprocessor power resets microprocessor operations that are sensitive to a power interruption. Upon restoration of microprocessor power, a reset device outputs a processor reset signal that forces the microprocessor to reboot and execute an initialization program. The processor reset signal also synchronously resets the notice device and the interrupt device means to maintain the cycle of intentional initialization of the microprocessor. The microprocessor is programmed to recognize that an initialization of the processor is scheduled to occur and therefore operates to complete current program tasks and initiates the storage of a selected set of operating data. The microprocessor stores the operating data within a memory storage device that remains powered during the interruption of power to the microprocessor. In response to the initialization program, the microprocessor operates to detect whether the initialization of the microprocessor corrupted any of the selected operating data stored within the memory storage device. If the microprocessor finds that the stored operating data is valid, the microprocessor begins operations using the stored operating data. ## Claims ### Claim 1 An apparatus for initializing a data processing system regardless of the operating state of said data processing system, comprising: notice means for applying a warning signal upon expiration of a first time interval to said data processing system to provide notice of initialization to said data processing system; switching means for momentarily interrupting electrical power by a power source to said data processing system; and interrupt means for applying an interrupt signal subsequent to said warning signal and upon expiration of a second time interval to cause said switching means to momentarily interrupt said electrical power and thereby reset said data processing system regardless of the operating state of said data processing system, wherein said notice means and said interrupt means are reset when said switching means operates to restore said electrical power to said data processing system. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said notice means and said interrupt means comprise timing devices. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein said second time interval is a fixed time period. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein said second time interval is a variable time period. ### Claim 5 (depends on 1) The apparatus of claim 1 further comprising a memory storage device connected to said data processing system, wherein said memory storage device remains powered when said switching means operates to momentarily interrupt said electrical power to said data processing system. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein said memory storage device is powered by a source other than said power source. ### Claim 7 (depends on 5) The apparatus of claim 5, wherein a reset means applies a processor reset signal to said data processing system when said switching means operates to restore said electrical power to said data processing system, said reset signal causing said data processing system to execute an initialization program. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein reset means generates said processor reset signal to synchronously reset said notice means and said interrupt means, when said switching means operates to restore said electrical power to said data processing system. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein said data processing system comprises means for generating fixed pattern data. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein said data processing system operates to complete current processing of operating data and causes the storage of a selected set of said operating data and said fixed pattern data within said memory storage device to provide stored selected data and stored fixed pattern data in response to said warning signal. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein said data processing system calculates a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, in response to said warning signal. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein said data processing system causes the storage of said checksum within said memory storage device to provide a stored checksum in response to said warning signal. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein said data processing system, in response to said processor reset signal, verifies the validity of said stored fixed pattern data by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 16 (depends on 13) The apparatus of claim 13, wherein said data processing system verifies the validity of said stored checksum, in response to verifying that said stored fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein said data processing system clears said stored fixed pattern data from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein said data processing system clears all of said operating data, other than said stored selected data, from said memory storage device in response to clearing said stored fixed pattern data. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein said data processing system executes an initial instruction set using said selected stored data in response to clearing all of said operating data other than said stored selected data. ### Claim 22 An apparatus for indicating the state of initialization readiness of a data processing system and for initializing said data processing system regardless of the operating state, comprising: first timing means for producing a first timing signal with a first time interval to provide said data processing system with notice of an impending initialization; second timing means, synchronized with said first means, for producing a second timing signal with a second time interval, said second time interval being a greater time interval than said first time interval; means for generating an initialization status signal to indicate the state of initialization readiness of said data processing system; switching means for momentarily interrupting electrical power supplied by a power source to said data processing system; and initialization means for applying an initialization signal within said second time interval to said switching means in response to said initialization status signal or applying said initialization signal to said switching means in response to said second timing signal; wherein said switching means operates to momentarily interrupt said electrical power to said data processing system in response to said initialization signal and thereby resets said data processing system. ### Claim 23 (depends on 22) The apparatus of claim 22, wherein said initialization means generates a timing reset signal to synchronously reset said first timing means and said second timing means and a reset signal that causes said data processing system to execute an initialization program in response to said switching means operating to restore said electrical power to said data processing system. ### Claim 24 (depends on 22) The apparatus of claim 22, wherein said initialization means generates a reset signal in response to said switching means operating to restore electrical power to said data processing system, said reset signal causing said data processing system to execute an initialization program. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein said initialization means applies a timing reset signal to said first timing means and said second timing means to synchronously reset said first timing means and said second timing means in response to said switching means operating to restore said electrical power to said data processing system. ### Claim 26 (depends on 25) The apparatus of claim 25, further comprising a memory storage device connected to said data processing system, wherein said memory storage device remains powered when said switching means operates to momentarily interrupt said electrical power to said data processing system. ### Claim 27 (depends on 26) The apparatus of claim 26, wherein said memory storage device is powered by a source other than said power source. ### Claim 28 (depends on 26) The apparatus of claim 26, wherein said data processing system comprises means for generating fixed pattern data. ### Claim 29 (depends on 28) The apparatus of claim 28, wherein said data processing system operates to complete current processing of operating data and causes the storage of a selected set of said operating data and said fixed pattern data within said memory storage device to provide stored selected data and stored fixed pattern data in response to said first timing signal and within said second time interval. ### Claim 30 (depends on 27) The apparatus of claim 27, wherein said data processing system calculates a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, in response to said first timing signal and within said second time interval. ### Claim 31 (depends on 30) The apparatus of claim 30, wherein said data processing system causes the storage of said checksum within said memory storage device to provide a stored checksum in response to said first timing signal and within said second time interval. ### Claim 32 (depends on 31) The apparatus of claim 31, wherein said data processing system generates said initialization status signal in response to causing the storage of said selected data, said fixed pattern data, and said checksum. ### Claim 33 (depends on 32) The apparatus of claim 32, wherein said data processing system, in response to said reset signal, verifies the validity of said stored fixed pattern data by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 34 (depends on 33) The apparatus of claim 33, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 35 (depends on 34) The apparatus of claim 34, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 36 (depends on 35) The apparatus of claim 35, wherein said data processing system verifies the validity of said stored checksum in response to verifying that said fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 37 (depends on 36) The apparatus of claim 36, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 38 (depends on 37) The apparatus of claim 37, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 39 (depends on 36) The apparatus of claim 36, wherein said data processing system clears said stored fixed pattern data from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 40 (depends on 37) The apparatus of claim 37, wherein said data processing system clears all of said operating data, other than said stored selected data, from said memory storage device in response to clearing said fixed pattern data. ### Claim 41 (depends on 40) The apparatus of claim 40, wherein said data processing system executes an initial instruction set using said selected stored data in response to clearing all of said operating data other than said stored selected data. ### Claim 42 An apparatus for initializing a data processing system, regardless of the operating state of said data processing system comprising: a computer for processing operating data, said computer providing an initialization status signal to indicate the state of initialization readiness of said computer; a power source for supplying electrical power to said computer; a switch for momentarily interrupting said electrical power to said computer; a memory storage device, connected to said computer, for storing said operating data, wherein said memory storage device remains powered when said switch operates to momentarily interrupt electrical power to said computer; a first timer for producing a first timing signal with a first time interval to provide said computer with notice of an impending initialization; a second timer for producing a second timing signal with a second time interval, said second time interval being a greater time interval than said first time interval; and an initialization circuit for applying an initialization signal within said second time interval to said switch in response to said initialization status signal or applying said initialization signal to said switch in response to said second timing signal; wherein said switch operates to momentarily interrupt said electrical power in response to said initialization signal and thereby resets said computer; and wherein said initialization circuit generates a reset signal to cause said computer to execute an initialization program and a timing reset signal to synchronously reset said first timer and said second timer in response to said switch operating to restore said electrical power to said computer. ### Claim 43 (depends on 42) The apparatus of claim 42, wherein said first timer is external to said computer. ### Claim 44 (depends on 43) The apparatus of claim 43, wherein said initialization circuit is external to said computer. ### Claim 45 (depends on 42) The apparatus of claim 42, wherein said first timer is internal to said computer. ### Claim 46 (depends on 42) The apparatus of claim 42, wherein each of said first time interval and said second time interval is a fixed time period. ### Claim 47 (depends on 42) The apparatus of claim 42, wherein each of said first time interval and said second time interval is a variable time interval. ### Claim 48 (depends on 42) The apparatus of claim 42, wherein said memory storage device is powered by a source other than said power source. ### Claim 49 (depends on 48) The apparatus of claim 48, wherein said computer comprises means for generating fixed pattern data. ### Claim 50 (depends on 49) The apparatus of claim 49, wherein said computer operates to complete current processing of said operating data and causes the storage of a selected set of said operating data and said fixed pattern data within said memory storage device to provide stored selected data and stored fixed pattern data in response to said first timing signal and within said second time interval. ### Claim 51 (depends on 50) The apparatus of claim 50, wherein said computer calculates a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, and causes the storage of said checksum within said memory storage device to provide a stored checksum in response to said first timing signal and within said second time interval. ### Claim 52 (depends on 51) The apparatus of claim 51, wherein said computer generates said initialization status signal in response to storing said selected data, said fixed pattern data, and said checksum. ### Claim 53 (depends on 52) The apparatus of claim 52, wherein said computer, in response to said reset signal, verifies the validity of said stored fixed pattern data by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 54 (depends on 53) The apparatus of claim 53, wherein said computer clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 55 (depends on 54) The apparatus of claim 54, wherein said computer executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 56 (depends on 55) The apparatus of claim 55, wherein said computer verifies the validity of said stored checksum in response to verifying that said fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 57 (depends on 56) The apparatus of claim 56, wherein said computer clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 58 (depends on 57) The apparatus of claim 57, wherein said computer executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 59 (depends on 58) The apparatus of claim 58, wherein said computer clears said stored fixed pattern data and all of said operating data, other than said stored selected data, from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 60 (depends on 59) The apparatus of claim 59, wherein said computer executes an initial instruction set upon said selected stored data in response to clearing said stored fixed pattern data and said all data. ### Claim 61 A method for initializing a data processing system, regardless of the operating state of said data processing system said data processing system powered by a power source supplying electrical power via a switching means, said switching means operative to momentarily interrupt said electrical power to said data processing system, comprising the steps of: applying a warning signal with a first time interval to said data processing system to provide notice of initialization to said data processing system; and applying an interrupt signal with a second time interval to said switching means to momentarily interrupt said electrical power supplied to said data processing system, said second time interval being a greater time interval than said first time interval, to reset said data processing system. ### Claim 62 (depends on 61) The method of claim 61, including the step of applying a reset signal in response to said switching means operating to restore said electrical power to said data processing system to cause said data processing system to execute an initialization program. ### Claim 63 (depends on 62) The method of claim 62, including the step of synchronously resetting said first time interval and said second time interval in response to said switching means operating to restore said electrical power to said data processing system. ### Claim 64 (depends on 62) The method of claim 62, including the step of completing current processing of operating data and causing the storage of a selected set of said operating data and fixed pattern data in a memory storage device connected to said data processing system to provide stored selected data and stored fixed pattern data in response to said warning signal and within said second time interval, wherein said memory storage device remains powered when said electrical power is interrupted to said data processing system. ### Claim 65 (depends on 64) The method of claim 64, including the step of calculating a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, in response to said warning signal and within said second time interval. ### Claim 66 (depends on 65) The method of claim 65, including the step of storing said checksum in said memory storage device to provide a stored checksum in response to said warning signal and within said second time interval. ### Claim 67 (depends on 66) The method of claim 66, including the step of verifying the validity of said stored fixed pattern data, in response to said reset signal, by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 68 (depends on 67) The method of claim 67, including the step of clearing said stored selected data, said stored fixed pattern data, stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 69 (depends on 68) The method of claim 68, including the step of executing an initial instruction set and building new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 70 (depends on 66) The method of claim 66, including the step of verifying said stored checksum, in response to verifying that said fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 71 (depends on 70) The method of claim 70, including the step of clearing said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 72 (depends on 71) The method of claim 71, including the step of executing an initial instruction set and building new operating data after said step of clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 73 (depends on 70) The method of claim 70, including the step of clearing said stored fixed pattern data from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 74 (depends on 73) The method of claim 73, including the step of clearing all of said data, other than said stored selected data, and said stored fixed pattern data from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 75 (depends on 74) The method of claim 74, including the step of executing an initial instruction set upon said selected stored data in response to clearing said all data other than said stored selected data, and said stored fixed pattern data. ### Claim 76 An apparatus for indicating the state of initialization readiness of a data processing system and for initializing said data processing system regardless of the operating state, comprising: first timing means for producing a first timing signal with a first time interval to provide said data processing system with notice of an impending initialization; second timing means, synchronized with said first means, for producing a second timing signal with a second time interval, said second time interval being a greater time interval than said first time interval; means for generating an initialization status signal to indicate the state of initialization readiness of said data processing system; switching means for momentarily interrupting electrical power supplied by a power source to said data processing system; and initialization means for applying a reset signal within said second time interval for initializing said data processing system in response to said initialization status signal or applying said initialization signal to said switching means in response to said second timing signal; wherein said switching means operates to momentarily interrupt said electrical power to said data processing system in response to said initiliazation signal and thereby resets said data processing system. ### Claim 77 (depends on 76) The apparatus of claim 76, wherein said initialization means supplies said reset signal to said data processing system in response to said switching means operating to restore said electrical power to said data processing system, said reset signal causing said data processing system to execute an initialization program. ### Claim 78 (depends on 77) The apparatus of claim 77, wherein said initialization means synchronously resets said first timing means and said second timing means by applying a timing reset signal to said first timing means and said second timing means in response to said initialization status signal and within said second time interval or by applying said timing reset signal in response to said switching means operating to restore said electrical power to said data processing system. ### Claim 79 (depends on 77) The apparatus of claim 77 further comprising a memory storage device connected to said data processing system, wherein said memory storage device remains powered when said switching means operates to momentarily interrupt electrical power to said data processing system. ### Claim 80 (depends on 79) The apparatus of claim 79, wherein said memory storage device is powered by a source other than said power source. ### Claim 81 (depends on 79) The apparatus of claim 79, wherein said data processing system comprises means for generating fixed pattern data. ### Claim 82 (depends on 81) The apparatus of claim 81, wherein said data processing system operates to complete current processing of operating data and causes the storage of a selected set of said operating data and said fixed pattern data within said memory storage device to provide stored selected data and stored fixed pattern data in response to said first timing signal and within said second time interval. ### Claim 83 (depends on 82) The apparatus of claim 82, wherein said data processing system calculates a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, in response to said first timing signal and within said second time interval. ### Claim 84 (depends on 83) The apparatus of claim 83, wherein said data processing system causes the storage of said checksum within said memory storage device to provide a stored checksum in response to said first timing signal and within said second time interval. ### Claim 85 (depends on 84) The apparatus of claim 84, wherein said data processing system generates said initialization status signal in response to causing the storage of said selected data, said fixed pattern data, and said checksum. ### Claim 86 (depends on 85) The apparatus of claim 85, wherein said data processing system, in response to said reset signal, verifies the validity of said stored fixed pattern data by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 87 (depends on 86) The apparatus of claim 86, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 88 (depends on 87) The apparatus of claim 87, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 89 (depends on 86) The apparatus of claim 86, wherein said data processing system verifies the validity of said stored checksum in response to verifying that said fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 90 (depends on 89) The apparatus of claim 89, wherein said data processing system clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 91 (depends on 90) The apparatus of claim 90, wherein said data processing system executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 92 (depends on 89) The apparatus of claim 89, wherein said data processing system clears said stored fixed pattern data from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 93 (depends on 92) The apparatus of claim 92, wherein said data processing system clears all of said operating data, other than said stored selected data, from said memory storage device in response to clearing said fixed pattern data. ### Claim 94 (depends on 93) The apparatus of claim 93, wherein said data processing system executes an initial instruction set using said selected stored data in response to clearing all of said operating data other than said stored selected data. ### Claim 95 An apparatus for initializing a data processing system, regardless of the operating state of said data processing system comprising: a computer for processing operating data, said computer providing an initialization status signal to indicate the state of initialization readiness of said computer; a switch for momentarily interrupting electrical power supplied by a power source to said computer; a memory storage device, connected to said computer, for storing said operating data, said memory storage device operative to remain powered when said switch operates to momentarily interrupt said electrical power to said computer; a first timer for producing a first timing signal with a first time interval to provide said computer with notice of an impending initialization; a second timer for producing a second timing signal with a second time interval, said second time interval being a greater time interval than said first time interval; and an initialization circuit for applying a reset signal to said computer in response to said initialization status signal to cause said computer to execute an initialization program or applying an initialization signal to said switch in response to said second timing signal, wherein said switch operates to momentarily interrupt said electrical power to said computer in response to said initialization signal and thereby resets said computer, wherein said initialization circuit synchronously resets said first timer and said second timer by applying a timing reset signal to each of said first timer and said second timer in response to said initialization status signal and within said second time interval or by applying said timing reset signal in response to said switch operating to restore said electrical power to said computer. ### Claim 96 (depends on 95) The apparatus of claim 95, wherein each of said first time interval and said second time interval is a fixed time period. ### Claim 97 (depends on 95) The apparatus of claim 95, wherein each of said first time interval and said second time interval is a variable time period. ### Claim 98 (depends on 95) The apparatus of claim 95, wherein said memory storage device is powered by a source other than said power source. ### Claim 99 (depends on 95) The apparatus of claim 95, wherein said initialization circuit supplies said reset signal to said computer in response to said switch operating to momentarily interrupt said electrical power to said computer, said reset signal causing said computer to execute said initialization program. ### Claim 100 (depends on 99) The apparatus of claim 99, wherein said computer comprises means for generating fixed pattern data. ### Claim 101 (depends on 100) The apparatus of claim 100, wherein said computer operates to complete current processing of said operating data and causes the storage of a selected set of said operating data and said fixed pattern data within said memory storage device to provide stored selected data and stored fixed pattern data in response to said first timing signal and within said second time interval. ### Claim 102 (depends on 101) The apparatus of claim 101, wherein said computer calculates a checksum, representative of the sum of said stored selected data and said stored fixed pattern data, and causes the storage of said checksum within said memory storage device to provide a stored checksum in response to said first timing signal and within said second time interval. ### Claim 103 (depends on 102) The apparatus of claim 102, wherein said computer generates said initialization status signal in response to storing said selected data, said fixed pattern data, and said checksum. ### Claim 104 (depends on 103) The apparatus of claim 103, wherein said computer, in response to said reset signal, verifies the validity of said stored fixed pattern data by comparing said stored fixed pattern data to said fixed pattern data. ### Claim 105 (depends on 104) The apparatus of claim 104, wherein said computer clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored fixed pattern data. ### Claim 106 (depends on 105) The apparatus of claim 105, wherein said computer executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 107 (depends on 104) The apparatus of claim 104, wherein said computer verifies the validity of said stored checksum in response to verifying that said fixed pattern data is valid, by calculating the sum of said stored selected data and said stored fixed pattern data to produce a new checksum and comparing said new checksum to said stored checksum. ### Claim 108 (depends on 107) The apparatus of claim 107, wherein said computer clears said stored selected data, said stored fixed pattern data, and said stored checksum from said memory storage device in response to detecting corruption of said stored checksum. ### Claim 109 (depends on 108) The apparatus of claim 108, wherein said computer executes an initial instruction set and builds new operating data in response to clearing said stored selected data, said stored fixed pattern data, and said stored checksum. ### Claim 110 (depends on 107) The apparatus of claim 107, wherein said computer clears said stored fixed pattern data and all of said operating data, other than said stored selected data, from said memory storage device in response to verifying that said stored checksum is valid. ### Claim 111 (depends on 110) The apparatus of claim 110, wherein said computer executes an initial instruction set upon said selected stored data in response to clearing said stored fixed pattern data and said all data. ### Claim 112 An apparatus for initializing a data processing system, regardless of the operating state of said data processing system, comprising: notice means for applying a warning signal upon expiration of a first time interval to said data processing system to provide notice of initialization to said data processing system; means for generating an initialization status signal subsequent to said warning signal to indicate the state of initialization readiness of said data processing system; switching means for momentarily interrupting electrical power by a power source to said data processing system; and interrupt means for applying an interrupt signal in response to said initialization status signal or upon expiration of a second time interval to cause said switching means to momentarily interrupt said electrical power and thereby reset said data processing system regardless of the operating state of said data processing system, wherein said notice means and said interrupt means are reset when said switching means operates to restore said electrical power to said data processing system. ### Claim 113 (depends on 112) The apparatus of claim 112, further comprising reset means for generating a processor reset signal to synchronously reset said notice means and said interrupt means when said switching means operates to restore said electrical power to said data processing system. ### Claim 114 (depends on 113) The apparatus of claim 113, wherein said reset means applies said processor reset signal to said data processing system when said switching means operates to restore said electrical power to said data processing system, said processor reset signal causing said data processing system to execute an initialization program. ### Claim 115 (depends on 114) The apparatus of claim 114, further comprising a memory storage device connected to said data processing system, wherein said memory storage device remains powered when said switching means operates to momentarily interrupt said electrical power to said data processing system. ### Claim 116 (depends on 115) The apparatus of claim 115, wherein said memory storage device is powered by a source other than said power source.