Patent US5760792A successfully refreshed from Google Patents.
US5760792A
Expired / Lapsed
US
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Fifo logical addresses for control and error recovery
Assignee: ZiiLabs Inc Ltd
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Filing: 1995-05-01
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Granted: 1998-06-02
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Expires: 2015-05-01
Abstract
Abstract An improved graphics processor is of the type having a graphics engine and a graphics FIFO buffer in communication with the graphics engine. The buffer is also in communication with a host processor over a bus so as to provide request code and data from the host processor to the graphics engine. The improvement in a preferred embodiment utilizes a plurality of logical FIFOs, including a normal FIFO and a protected FIFO, having addresses all mapping to the same physical graphics FIFO buffer. User access via an application is provided only to the normal FIFO, whereas system level code is provided access to all of the logical FIFOs, so that the protected FIFO can be used for control of the graphics processor. In a further embodiment, a logical sync FIFO is employed also. The sync FIFO is used in error recovery to receive and store a request that can be detected by the graphics engine as a cue to restart normal processing. Related methods are also provided.
Inventors
- 👤 Jeffrey J. Holt
- 👤 David W. Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:29
CPC Classifications
G; G06; G06T; G06T1/00; G06T1/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
An improved graphics processor of the type having a graphics engine and a graphics FIFO buffer in communication with the graphics engine, the buffer also in communication with a host processor over a bus so as to provide request code and data from the host processor to the graphics engine, wherein the improvement comprises: (a) a plurality of logical FIFOs, including a normal FIFO and a protected FIFO, having addresses all mapping to the same physical graphics FIFO buffer; (b) means for providing user access via an application only to the normal FIFO; and (c) means for providing system level code access to all of the logical FIFOs, so that the protected FIFO can be used for control of the graphics processor.
Claim 2
Dependent Claim
122 words
An improved graphics processor of the type having a graphics engine and a graphics FIFO buffer in communication with the graphics engine, the buffer also in communication with a host processor over a bus so as to provide request code and data from the host processor to the graphics engine, wherein the improvement comprises: (a) a plurality of logical FIFOs, including a normal FIFO and a protected FIFO, having addresses all mapping to the same physical graphics FIFO buffer; (b) means for providing user access via an application only to the normal FIFO; and (c) means for providing system level code access to all of the logical FIFOs, so that the protected FIFO can be used for control of the graphics processor.
Claim 3
Dependent Claim
64 words
A processor according to claim 1, further comprising: a logical sync FIFO, in addition to the normal FIFO and the protected FIFO, having an address mapping to the same physical graphics FIFO buffer; and means for using the sync FIFO in error recovery to receive and store a request that can be detected by the graphics engine as a cue to restart normal processing.
Claim 4
Independent Claim
140 words
A method of controlling a graphics processor of the type having a graphics engine and a graphics FIFO buffer in communication with the graphics engine, the buffer also in communication with a host processor over a bus so as to provide request code and data from the host processor to the graphics engine, the method comprising: (a) causing the graphics FIFO buffer to have a plurality of logical addresses, including a normal address and a protected address, all mapping to this same physical buffer, so as to create a plurality of logical FIFOs including a normal FIFO and a protected FIFO; (b) providing user access via an application only to the normal FIFO; and (c) providing system level code access to all of the logical FIFOs, so that the protected FIFO can be used for control of the graphics processor.
Claim 5
Independent Claim
140 words
A method of controlling a graphics processor of the type having a graphics engine and a graphics FIFO buffer in communication with the graphics engine, the buffer also in communication with a host processor over a bus so as to provide request code and data from the host processor to the graphics engine, the method comprising: (a) causing the graphics FIFO buffer to have a plurality of logical addresses, including a normal address and a protected address, all mapping to this same physical buffer, so as to create a plurality of logical FIFOs including a normal FIFO and a protected FIFO; (b) providing user access via an application only to the normal FIFO; and (c) providing system level code access to all of the logical FIFOs, so that the protected FIFO can be used for control of the graphics processor.
Claim 6
Dependent Claim
74 words
A method according to claim 3, wherein step (a) includes the step of causing the graphics FIFO buffer to have a sync address so as to create a logical sync FIFO, in addition to the normal FIFO and the protected FIFO, the method further comprising: (d) using the sync FIFO in error recovery to receive and store a request that can be detected by the graphics engine as a cue to restart normal processing.
References Cited (Backward Citations)
US5185878A
Cited
US5291608A
Cited
US5043981A
Cited
US5119374A
Cited
US5371849A
Cited
US5303321A
Cited
US5295246A
Cited
US5426639A
Cited
US5434957A
Cited
US5402147A
Cited
US5485626A
Cited
US5428779A
Cited
US5524265A
Cited
US5555244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-01 | 2001-12-01 | 2002-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-01 | 2005-12-01 | 2006-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-01 | 2009-12-01 | 2010-06-02 | $7700.00 | Window Closed / Lapsed |