Encrypted program executing apparatus
CA 2193114 C · Owner: Hirotani, Takayuki · Inventors: Hirotani, Takayuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An encrypted part of the encrypted program loaded in an memory device is received by a one-chip microcomputer and decrypted according to a decrypting program which is stored in advance in an ROM and which cannot be read out to an external bus. The decrypted program is stored in an cache memory, and a cache function inhibition flag is set in a control register in accordance with a storage area of the decrypted program in the cache memory. Therefore, the decrypted program is inhibited from being read out to the external bus. The decrypted program is combined with the non-encrypted part of the program stored in the memory device and the, combined program is executed by a CPU. The encrypted …
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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 April 18, 1996 and granted June 13, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 18, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 18, 2018.
- 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
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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.