Microprocessor back-up system
CA 1282151 C · Owner: Gec Plessey Telecommunications Limited · Inventors: Harrold, David R.; Williams, Howard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Microprocessor Back-up System A back-up system for the main processor of a digital telephone exchange comprises a storage array (120) of CMOS dynamic RAMS. Failure of the normal power supply triggers power changeover logic (20) so that the array (120) is refreshed in a manner to make best possible use of the failing power supply. Thereafter the system supplies regular refreshing to the array (120) but prevents changes in the data already stored.
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
- Granted March 26, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 26, 2008.
- 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.