Patent US5289583A successfully refreshed from Google Patents.
US5289583A
Expired / Lapsed
US
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Bus master with antilockup and no idle bus cycles
Assignee: International Business Machines Corp
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Filing: 1990-10-19
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Granted: 1994-02-22
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Expires: 2010-10-19
Abstract
Abstract Bus master for use in computer system includes logic for determining the number of words remaining to be transferred in a DMA operation to supply signals to permit arbitration to start for the next DMA request, thereby avoiding an idle cycle. A timeout state machine is also included to prevent the bus master state machine from hanging in a state with no exit. Errors can be masked to permit analysis of system problems.
Inventors
- 👤 Lisa L. Fischer
- 👤 Stephen D. Hanna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:55
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/14; G06F13/20; G06F13/28; G06F13/30; G06F13/36; G06F13/368
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
141 words
An arbitration system comprising: resource means; resource arbiter means for controlling access to the resource means by arbitrating requests therefor; and a plurality of resource masters, each resource master including means for supplying to said resource arbiter means signals representing requests for access to the resource means, sequencing means for controlling steps in communicating with the resource means, means for supplying signals to the resource arbiter when access to the resource means is attained to retain access to the resource means by preventing arbitration of other access requests to the resource means, means for determining that a given number of transfers remain, said given number being determined from the total number of transfers to be made and the total number of transfers to be made consecutively, and means responsive to said determining means for inhibiting signals from the signal supplying means.
Claim 2
Dependent Claim
141 words
An arbitration system comprising: resource means; resource arbiter means for controlling access to the resource means by arbitrating requests therefor; and a plurality of resource masters, each resource master including means for supplying to said resource arbiter means signals representing requests for access to the resource means, sequencing means for controlling steps in communicating with the resource means, means for supplying signals to the resource arbiter when access to the resource means is attained to retain access to the resource means by preventing arbitration of other access requests to the resource means, means for determining that a given number of transfers remain, said given number being determined from the total number of transfers to be made and the total number of transfers to be made consecutively, and means responsive to said determining means for inhibiting signals from the signal supplying means.
Claim 3
Dependent Claim
22 words
The arbitration system claimed in claim 1 wherein said given number is further determined from the number of scans required for tessellation.
Claim 4
Dependent Claim
47 words
The arbitration system as claimed in claim 1 wherein each resource master further includes timeout means for timing delays between steps controlled by said sequencing means, and means responsive to said timeout means for resetting said sequencing means when a predetermined time has elapsed between consecutive steps.
Claim 5
Dependent Claim
42 words
The arbitration system as claimed in claim 1 wherein each resource master further includes means responsive to error signals for inhibiting said sequencing means when an error occurs, and means for selectively inhibiting said error responsive means for inhibiting said sequencing means.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |