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Expired Canadian patentCanada

Multiprocessor system and data transmission apparatus thereof

CA 2062909 C · Owner: International Business Machines Corporation · Inventors: Shimizu, Shigenori; Murata, Hiroki

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

The bandwidth of the data transfer among a main memory and snoopy caches is improved by solving the bus neck in a multiprocessor system using a snoopy cache technique. Shared bus coupling is employed for an address/command bus requiring bus snoop whereas multiple data paths coupled by an interconnection network are used for the data bus not requiring bus snoop. The multiple data paths reflect the order of the snoopy operations on the order of data transfer such as to maintain data consistency among the caches.

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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 March 12, 1992 and granted April 1, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 12, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 12, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 12, 1992
GrantedApril 1, 1997
Term endedMarch 12, 2012
Patent numberCA 2062909 C
Classification (IPC)G06F15/16 +1 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedMarch 12, 1992Patent grantedApril 1, 1997Term endedMarch 12, 2012

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.