Overflow detection system and its circuit for use in addition and subtraction
CA 2072265 C · Owner: Nec Corporation · Inventors: Suzuki, Kazumasa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In an overflow detection circuit for A+B operation an inverter outputs a value V B, comprising inverted bits of a numeric part of an addend B. A comparator receives as an input a numeric part V A of an augend A and an output V B of, the inventer, and responsive thereto outputs a signal C indicating whether or not V A > V B, is given. Sign parts S A and S B of A and B and the output C of the comparator are inputted into a decoder and an overflow signal "0" is outputted. The decoder is a circuit which outputs "1" when S A and S B are "0" and V A(V A > V B') is large and when S A and S B are "1" and V A is small (VA=V B'), and output "0" in other cases. If the comparator is a circuit for …
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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 June 25, 1992 and granted December 16, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 25, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 25, 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.
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.