US4974148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bus arbiter with equitable priority scheme
Assignee: Motorola Solutions Inc
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Filing: 1987-07-06
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Granted: 1990-11-27
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Expires: 2007-07-06
Abstract
Abstract A bus arbiter for a multi-processor computer provides fair access by dynamically adjusting a base variable of a counter which is determined from a processor number of a previously access-requesting processor having the highest processor number. The counter then varies priority between a minimum processor number, such as zero, and the base variable of the counter. The priority signal from the counter and the current access-requesting processors are then provided to a memory device. The memory device is used to determine which current access-requesting processor is permitted to access the bus.
Inventors
- 👤 Keith D. Matteson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:40
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/14; G06F13/36; G06F13/362; G06F13/364
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
199 words
A bus arbiter for a computer system comprising a plurality of processors coupled to a bus to which at least one of said processors requests access by generating a bus request signal, each of said plurality of processors having associated therewith a processor number, said bus arbiter comprising: clock means for generating a clock signal, said clock means comprising; a first gate responsive to said bus request signal and generating a first output signal; first logic means responsive to said bus request signal, to a delayed clock signal, and to a bus grant signal for generating a second output signal; a second gate responsive to said first and second output signals and generating said clock signal; signal delay means responsive to said clock signal for generating said delayed clock signal; second logic means for generating a count signal representing a number of a processor being given priority; latch means responsive to said bus request signal and to said clock signal for generating a latched bus request signal; and bus grant means responsive to said latched bus request signal and to said count signal for generating said bus grant signal, permitting one of said access-requesting processors to access said bus.
Claim 2
Dependent Claim
199 words
A bus arbiter for a computer system comprising a plurality of processors coupled to a bus to which at least one of said processors requests access by generating a bus request signal, each of said plurality of processors having associated therewith a processor number, said bus arbiter comprising: clock means for generating a clock signal, said clock means comprising; a first gate responsive to said bus request signal and generating a first output signal; first logic means responsive to said bus request signal, to a delayed clock signal, and to a bus grant signal for generating a second output signal; a second gate responsive to said first and second output signals and generating said clock signal; signal delay means responsive to said clock signal for generating said delayed clock signal; second logic means for generating a count signal representing a number of a processor being given priority; latch means responsive to said bus request signal and to said clock signal for generating a latched bus request signal; and bus grant means responsive to said latched bus request signal and to said count signal for generating said bus grant signal, permitting one of said access-requesting processors to access said bus.
Claim 3
Dependent Claim
44 words
The bus arbiter recited in claim 1, wherein said bus grant means comprises: a memory receiving said latched bus request signal and said count signal and providing said bus grant signal; and buffer means coupled to said memory for driving said bus grant signal.
Claim 4
Dependent Claim
38 words
The bus arbiter recited in claim 2 wherein said signal delay means delays said clock signal by a time greater than a time delay of a signal transmitted through said latch means, said memory, and said buffer means.
Claim 5
Dependent Claim
16 words
The bus arbiter recited in claim 1 wherein said first gate comprises a logical NAND gate.
Claim 6
Dependent Claim
19 words
The bus arbiter recited in claim 1 wherein said first and second logic means comprise programmable array logic devices.
Claim 7
Dependent Claim
16 words
The bus arbiter recited in claim 1 wherein said second gate comprises a logical AND gate.
Claim 8
Dependent Claim
25 words
The bus arbiter of claim 1 wherein said number of said processor being given priority is a highest processor number of a previously requesting processor.
References Cited (Backward Citations)
US3603935A
Cited
US4017841A
Cited
US4009470A
Cited
US4023143A
Cited
US4232294A
Cited
US4314335A
Cited
US4320467A
Cited
US4536839A
Cited
US4535330A
Cited
US4814974A
Cited
US4675812A
Cited
US4730268A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |