Deferred comparison multiplier checker
CA 2019064 C · Owner: Tandem Computers Incorporated · Inventors: Jardine, Robert L.; Horst, Robert W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a data processing system, a multiplication operation is immediately followed by a redundant multiplication operation, using the same albeit altered, operands, to check the initial result. The initial result is immediately available for use, but the check is not performed until some time later. The original operands are altered for the redundant multiplication operation by shifting one operand 1 bit, and swapping them before multiplication.
Read the whole patent
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 June 15, 1990 and granted May 11, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 2012.
- 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.