System direct memory access (dma) support logic for pci based computer system
CA 2124031 C · Owner: International Business Machines Corporation · Inventors: Hofmann, Richard Gerard; Amini, Nader; Bland, Patrick Maurice
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A direct memory access (DMA) support mechanism is provided for use in a computer system which comprises (i) a central processing unit (CPU) connected to system memory by a first system bus and a second system bus connected to the CPU; (ii) a host bridge connecting the second system bus to a peripheral bus; (iii) an input/output (I/O) bridge connecting the peripheral bus to a standard I/O bus the standard I/O bus having a plurality of standard I/O devices attached thereto; and (v) arbitration logic which functions in an arbitration mode for arbitrating between the plurality of standard I/O devices competing for access to the standard I/O bus and in a grant mode wherein a selected standard …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 20, 1994 and granted August 24, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 2016.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.