EP0415515A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Computer system
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1990-04-06
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Granted: —
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Expires: 2010-04-06
Abstract
Abstract A computer system (10) configured particularly for operation of real time tasks (30) includes an executive scheduling function (2) for scheduling tasks in accordance with predetermined priorities and categories. Asynchronous I/O interrupts are prohibited as well as task execution exceeding a predetermined worst case execution time. Attempts to access unauthorised memory or I/O addresses terminates execution of the task and returns operation to the next most critical task.
Inventors
- 👤 Harry R. Seebode
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:54
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/46; G06F9/48; G06F9/4806; G06F9/4843; G06F9/4881; G06F9/4887; G06F13/00; G06F12/00; G06F12/14; G06F12/1458; G06F12/1483; G06F9/44
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
91 words
A method for operating a computer system to perform real time tasks (30), comprising the steps of: invoking an executive scheduling function (22) upon receipt of a real time interrupt; scheduling real time tasks (30) during time interval ticks sufficient to support all such real time tasks; scheduling real time tasks in accordance with a predetermined categorisation of each task based on the ability of that task to tolerate interruption; and selectively prohibiting access by each task to memory addresses outside a predetermined contiguous address space authorised for each such task.
Claim 2
Independent Claim
91 words
A method for operating a computer system to perform real time tasks (30), comprising the steps of: invoking an executive scheduling function (22) upon receipt of a real time interrupt; scheduling real time tasks (30) during time interval ticks sufficient to support all such real time tasks; scheduling real time tasks in accordance with a predetermined categorisation of each task based on the ability of that task to tolerate interruption; and selectively prohibiting access by each task to memory addresses outside a predetermined contiguous address space authorised for each such task.
Claim 3
Dependent Claim
20 words
A method as defined in Claim 1, wherein the real time tasks are scheduled in accordance with a predetermined prioritization.
Claim 4
Dependent Claim
22 words
A method as defined in Claim 1 or 3, wherein required internal computer assets are individually initialised for each task as scheduled.
Claim 5
Dependent Claim
17 words
A method as defined in Claim 1, 2 or 3, wherein only synchronous I/O interrupts are accepted.
Claim 6
Dependent Claim
33 words
A method as defined Claim 1, 2, 3 or 4, wherein the execution time of each real time task is monitored in accordance with a predetermined worst case execution time for that task.
Claim 7
Dependent Claim
29 words
A method as defined in Claim 5, wherein any task is terminated upon the detection of execution time exceeding the predetermined worst case execution time specified for that task.
Claim 8
Independent Claim
32 words
A method as defined in any one of Claims 1 to 6, wherein access by each scheduled task is prohibited to I/O buffer addresses except those specifically authorised for each such task.
Claim 9
Dependent Claim
27 words
A method as defined in Claim 7, wherein any task is terminated upon the detection of an attempt by that task to access unauthorised I/O buffer addresses.
Claim 10
Independent Claim
40 words
A method as defined in any one of Claims 1 to 9, wherein any task is terminated upon the detection of any attempt by that task to access memory addresses outside the predetermined contiguous address space authorised for that task.
Claim 11
Dependent Claim
81 words
Apparatus (10) for performing real time computer tasks (30), comprising, in combination: means (22) responsive to real time interrupts for scheduling real time tasks (30) during time interval ticks sufficient to support all such real time tasks (30) in accordance with a predetermined categorisation of each task based on the ability of that task to tolerate interruption; and means (20) for selectively prohibiting access by each task to memory addresses outside a predetermined contiguous address space authorised for each such task.
Claim 12
Dependent Claim
81 words
Apparatus (10) for performing real time computer tasks (30), comprising, in combination: means (22) responsive to real time interrupts for scheduling real time tasks (30) during time interval ticks sufficient to support all such real time tasks (30) in accordance with a predetermined categorisation of each task based on the ability of that task to tolerate interruption; and means (20) for selectively prohibiting access by each task to memory addresses outside a predetermined contiguous address space authorised for each such task.
Claim 13
Dependent Claim
37 words
Apparatus as defined in Claim 10 further including: means (22) for terminating any task (30) upon detection of an attempt by that task to acess memory addresses outside the predetermined contiguous address space authorised for that task.
Claim 14
Dependent Claim
21 words
Apparatus as defined in Claim 10 or 11, wherein the real time tasks are scheduled in accordance with a predetermined prioritisation.
Claim 15
Dependent Claim
25 words
Apparatus as defined in Claim 10, 11 or 12 further including: means (22) for individually initialising required internal computer assets for each tasks as scheduled.
Claim 16
Dependent Claim
17 words
Apparatus as defined in Claim 10, 11, 12 or 13, wherein only synchronous I/O interrupts are accepted.
Claim 17
Dependent Claim
37 words
Apparatus as defined in anyone of Claims 10 to 14 further including: means (22) for terminating the execution of each real time task when the execution time for that task exceeds a predetermined worst case execution time.
Claim 18
Dependent Claim
34 words
Apparatus as defined in any one of Claims 10 to 15 further including: means (28) for denying access by each scheduled task to I/O buffer addresses except those specifically authorised for each such task.
Claim 19
Dependent Claim
38 words
Apparatus as defined in any one of Claims 10 to 16 further including: means (22) for terminating the execution of each real time task upon detection of an attempt by that task to access unauthorised I/O buffer addresses.
References Cited (Backward Citations)
No citation records indexed.
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