Patent EP0404560A2 successfully refreshed from Google Patents.
EP0404560A2
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EP
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Improved multiprocessor system
Assignee: Sun Microsystems Inc
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Filing: 1990-06-21
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Granted: —
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Expires: 2010-06-21
Abstract
Abstract A digital data processing system includes a plurality of central processor units (40A, 40B, 40C) which share and access a common memory (44A, 44B, 44C) through a memory management element (46) . The memory management element permits, inter alia, data in the common memory to be accessed in at least two modes. In the first mode, all central processing units requesting access to a given datum residing in memory are signalled of the datums existence. In the second mode, only selected central processing units requesting access to a resident datum are notified that it exists, while others requesting access to the datum are signalled that it does not exist. The common memory can include a plurality of independent memory elements (44A, 44B, 44C) each coupled to and associated with, a respective one of the central processing units. A central processing unit can include a post-store element for effecting the transfer of copies of data stored in its associated memory element to a memory element associated with another central processing unit.
Inventors
- 👤 Steven J. Frank
- 👤 Henry Burkhardt, Iii
- 👤 James B. Rothnie
- 👤 Benson I. Margulies
- 👤 Frederick D. Weber
- 👤 Linda Q. Lee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 21:12
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/30; G06F9/38; G06F9/3861; G06F9/3865; G06F11/00; G06F11/004; G06F15/00; G06F15/16; G06F15/163; G06F15/173; G06F15/17337
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
222 words
A digital data processing system comprising A. at least first and second central processing units, B. common memory means, coupled to said first and second central processing units, for storing an information-representative signal, said information-representative signal normally being concurrently accessible for access by said first and second central processing units, C. said first and second central processing units each including access request means for generating a signal representative of a request for access to said information-representative signal, and D. memory management means, coupled to said first and second central processing units and to said common memory means, for selectively providing at least first and second alternative modes of access to said information-representative signal, said first alternative mode for responding to an access-request signal generated by any of said first and second central processing units for signalling the requesting central processing unit that the requested information-representative signal is stored in said common memory means, said second alternative mode for responding to an access-request signal generated by a selected one of said central processing units for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other of said central processing units for signalling that the requested information-representative signal is not stored in said common memory means.
Claim 2
Dependent Claim
222 words
A digital data processing system comprising A. at least first and second central processing units, B. common memory means, coupled to said first and second central processing units, for storing an information-representative signal, said information-representative signal normally being concurrently accessible for access by said first and second central processing units, C. said first and second central processing units each including access request means for generating a signal representative of a request for access to said information-representative signal, and D. memory management means, coupled to said first and second central processing units and to said common memory means, for selectively providing at least first and second alternative modes of access to said information-representative signal, said first alternative mode for responding to an access-request signal generated by any of said first and second central processing units for signalling the requesting central processing unit that the requested information-representative signal is stored in said common memory means, said second alternative mode for responding to an access-request signal generated by a selected one of said central processing units for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other of said central processing units for signalling that the requested information-representative signal is not stored in said common memory means.
Claim 3
Dependent Claim
39 words
A digital data processing system according to claim 1, wherein at least said selected central processing unit includes anchor means for determining which of said first and second alternative access modes to provide for accessing the requested information-representative signal.
Claim 4
Dependent Claim
50 words
A digital data processing system according to claim 1, wherein said common memory means comprises first and second memory elements, said first memory element being coupled to and associated with said first central processing unit, said second memory element being coupled to and associated with said second central processing unit.
Claim 5
Dependent Claim
38 words
A digital data processing system according to claim 3, wherein said memory management means includes means for selectively storing the requested information-representative signal exclusively in the memory element associated with a requesting one of said central processing units.
Claim 6
Dependent Claim
132 words
A digital data processing system according to claim 4, wherein said memory management means includes means for selectively responding, in said first alternative access mode, to an access-request signal generated by any said central processing unit for signalling that central processing unit that the requested information-representative signal is stored in the common memory means, and responding, in said second alternative mode, to an access-request signal generated by the central processing unit associated with the memory element exclusively storing the requested information-representative signal for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other central processing unit, for signalling that central processing unit the requested information-representative signal is not stored in said common memory means.
Claim 7
Dependent Claim
88 words
A digital data processing system according to claim 5, wherein the memory management means comprises directory means associated with at least a memory element storing a selected information-representative signal, said descriptor signal representing one or more characteristics of that information-representative signal and including an ANCHOR signal having a status indicative of accessibility of that information-representative signal, and B. said memory management means including means responsive to said ANCHOR signal for determining which of said first and second alternative access modes to provide for accessing the selected information-representative signal.
Claim 8
Dependent Claim
34 words
A digital data processing system according to claim 6, wherein the central processing unit associated with the memory element storing the selected information-representative signal includes means for setting the status of said ANCHOR signal.
Claim 9
Dependent Claim
187 words
A digital data processing system comprising A. plural processing cells, each including a central processing unit coupled to an associated memory element, each said memory element being capable of storing one or more information-representative signals, B. memory management means coupled to said plural memory elements for accessing one or more information-representative signals stored in said plural memory elements, C. at least a first one of said central processing units including means for generating an ownership-request signal representative of a request for priority access to an information-representative signal, D. said memory management means including memory coherence means responsive to said ownership-request signals for allocating, exclusively, within the memory element associated with the first central processing unit, physical storage space for a first requested information-representative signal and for storing that signal therein, said first information-representative signal being one for which physical storage space is allocated in the memory element associated with the second central processing unit, and E. at least the first central processing unit including post-store means for effecting transfer of a copy of said information-representative signal to the memory element associated with said second central processing unit.
Claim 10
Dependent Claim
187 words
A digital data processing system comprising A. plural processing cells, each including a central processing unit coupled to an associated memory element, each said memory element being capable of storing one or more information-representative signals, B. memory management means coupled to said plural memory elements for accessing one or more information-representative signals stored in said plural memory elements, C. at least a first one of said central processing units including means for generating an ownership-request signal representative of a request for priority access to an information-representative signal, D. said memory management means including memory coherence means responsive to said ownership-request signals for allocating, exclusively, within the memory element associated with the first central processing unit, physical storage space for a first requested information-representative signal and for storing that signal therein, said first information-representative signal being one for which physical storage space is allocated in the memory element associated with the second central processing unit, and E. at least the first central processing unit including post-store means for effecting transfer of a copy of said information-representative signal to the memory element associated with said second central processing unit.
Claim 11
Independent Claim
215 words
A method for operating a multiprocessor digital data processing system of the type having at least first and second central processing units and a common memory means coupled to said first and second central processing units for storing an information-representative signal, said information-representative signal normally being concurrently accessible for access by said first and second central processing units, said method comprising the steps of A. generating, within any of first and second central processing units, an access-request signal representative of a request for access to said information-representative signal, B. responding to the access-request signal for selectively executing at least first and second alternative access steps, said first access step including responding to an access-request signal generated by any of said first and second central processing units for signalling the requesting central processing unit that the requested information-representative signal is stored in said common memory means, said second alternative access step including responding to an access-request signal generated by a selected one of said central processing units for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other of said central processing units for signalling that the requested information-representative signal is not stored in said common memory means.
Claim 12
Independent Claim
215 words
A method for operating a multiprocessor digital data processing system of the type having at least first and second central processing units and a common memory means coupled to said first and second central processing units for storing an information-representative signal, said information-representative signal normally being concurrently accessible for access by said first and second central processing units, said method comprising the steps of A. generating, within any of first and second central processing units, an access-request signal representative of a request for access to said information-representative signal, B. responding to the access-request signal for selectively executing at least first and second alternative access steps, said first access step including responding to an access-request signal generated by any of said first and second central processing units for signalling the requesting central processing unit that the requested information-representative signal is stored in said common memory means, said second alternative access step including responding to an access-request signal generated by a selected one of said central processing units for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other of said central processing units for signalling that the requested information-representative signal is not stored in said common memory means.
Claim 13
Dependent Claim
45 words
A method of operating a multiprocessor digital data processing system according to claim 9, including the step of determining, with a one of said selected central processing units, which of said first and second alternative access modes to provide for accessing the requested information-representative signal.
Claim 14
Dependent Claim
81 words
A method of operating a multiprocessor digital data processing system according to claim 8, wherein said common memory means comprises first and second memory elements, said first memory element being coupled to and associated with said first central processing unit, said second memory element being coupled to and associated with said second central processing unit, said method comprising the step of storing the requested information-representative signal exclusively in the memory element associated with a selected one of said central processing units.
Claim 15
Dependent Claim
137 words
A method of operating a multiprocessor digital data processing system according to claim 11, wherein said first alternative access step includes the steps of responding to an access-request signal generated by any of said central processing unit for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and said second alternative access step includes the step of responding to an access-request signal generated by the central processing unit associated with the memory element exclusively storing the requested information-representative signal for signalling that central processing unit that the requested information-representative signal is stored in said common memory means, and for responding to an access-request signal generated by the other central processing unit, for signalling that central processing unit the requested information-representative signal is not stored in said common memory means.
Claim 16
Independent Claim
220 words
A method for operating a multiprocessor digital data processing system of the type having plural processing cells, each including a central processing unit coupled to an associated memory element, each said memory element being capable of storing one or more information-representative signals, memory management means coupled to said plural memory elements for accessing one or more information-representative signals stored in said plural memory elements, said method comprising the steps of A. generating, within at least a first one of said central processing units, an ownership-request signal representative of a request for priority access to an information-representative signal, B. responding to said ownership-request signal for allocating, exclusively, within the memory element associated with the first central processing unit, physical storage space for a first requested information-representative signal and for storing that signal therein, C. generating, within at least a second one of said central processing units, a read-only request signal representative of a request for secondary access to said first information-representative signal, D. responding to said read-only request signal for transferring a copy of a first information-representative signal to the memory element associated with said second central processing unit, E. selectively transferring a copy of the first information-representative signal from the memory element associated with said first central processing unit to the memory element associated with said second central processing unit.
Claim 17
Independent Claim
220 words
A method for operating a multiprocessor digital data processing system of the type having plural processing cells, each including a central processing unit coupled to an associated memory element, each said memory element being capable of storing one or more information-representative signals, memory management means coupled to said plural memory elements for accessing one or more information-representative signals stored in said plural memory elements, said method comprising the steps of A. generating, within at least a first one of said central processing units, an ownership-request signal representative of a request for priority access to an information-representative signal, B. responding to said ownership-request signal for allocating, exclusively, within the memory element associated with the first central processing unit, physical storage space for a first requested information-representative signal and for storing that signal therein, C. generating, within at least a second one of said central processing units, a read-only request signal representative of a request for secondary access to said first information-representative signal, D. responding to said read-only request signal for transferring a copy of a first information-representative signal to the memory element associated with said second central processing unit, E. selectively transferring a copy of the first information-representative signal from the memory element associated with said first central processing unit to the memory element associated with said second central processing unit.
References Cited (Backward Citations)
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