Multiprocessor interrupt control
CA 2026770 A1 · Owner: Compaq Computer Corporation · Inventors: Culley, Paul R.; Landry, John A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Two independently operating microprocessors share common control, data and address buses. A first of the microprocessors is assigned, when it is on the buses to, respond to all maskable interrupts by causing placement of an interrupt vector on the bus at the start of the next bus cycle. When the second microprocessor is on the buses and a maskable interrupt is received, the start of the next bus cycle is inhibited from causing an interrupt vector to be placed on the bus.
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 October 2, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 2, 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.